Merge lp:~raharper/ubuntu/xenial/curtin/pkg-sru-revno425 into lp:~smoser/ubuntu/xenial/curtin/pkg

[Ryan Harper]

Import new upstream snapshot (revno 425)

New Upstream snapshot:
- unittest,tox.ini: catch and fix issue with trusty-level mock of open
- block/mdadm: add option to ignore mdadm_assemble errors (LP: #1618429)
- curtin/doc: overhaul curtin documentation for readthedocs.org (LP: #1351085)
- curtin.util: re-add support for RunInChroot (LP: #1617375)
- curtin/net: overhaul of eni rendering to handle mixed ipv4/ipv6 configs
- curtin.block: refactor clear_holders logic into block.clear_holders and cli cmd
- curtin.apply_net should exit non-zero upon exception. (LP: #1615780)
- apt: fix bug in disable_suites if sources.list line is blank.
- vmtests: disable Wily in vmtests
- Fix the unittests for test_apt_source.
- get CURTIN_VMTEST_PARALLEL shown correctly in jenkins-runner output
- fix vmtest check_file_strippedline to strip lines before comparing
- fix whitespace damage in tests/vmtests/__init__.py
- fix dpkg-reconfigure when debconf_selections was provided. (LP: #1609614)
- fix apt tests on non-intel arch
- Add apt features to curtin. (LP: #1574113)
- vmtest: easier use of parallel and controlling timeouts
- mkfs.vfat: add force flag for formating whole disks (LP: #1597923)
- block.mkfs: fix sectorsize flag (LP: #1597522)
- block_meta: cleanup use of sys_block_path and handle cciss knames (LP: #1562249)
- block.get_blockdev_sector_size: handle _lsblock multi result return (LP: #1598310)
- util: add target (chroot) support to subp, add target_path helper.
- block_meta: fallback to parted if blkid does not produce output (LP: #1524031)
- commands.block_wipe: correct default wipe mode to 'superblock'
- tox.ini: run coverage normally rather than separately
- move uefi boot knowledge from launch and vmtest to xkvm

=== modified file 'Makefile'
--- Makefile	2016-05-10 16:13:29 +0000
+++ Makefile	2016-10-03 18:55:20 +0000
@@ -49,5 +49,7 @@
 sync-images:
 	@$(CWD)/tools/vmtest-sync-images
 
+clean:
+	rm -rf doc/_build
 
-.PHONY: all test pyflakes pyflakes3 pep8 build
+.PHONY: all clean test pyflakes pyflakes3 pep8 build
 
=== modified file 'curtin/__init__.py'
--- curtin/__init__.py	2015-11-23 16:22:09 +0000
+++ curtin/__init__.py	2016-10-03 18:55:20 +0000
@@ -33,6 +33,10 @@
     'SUBCOMMAND_SYSTEM_INSTALL',
     # subcommand 'system-upgrade' is present
     'SUBCOMMAND_SYSTEM_UPGRADE',
+    # supports new format of apt configuration
+    'APT_CONFIG_V1',
 ]
 
+__version__ = "0.1.0"
+
 # vi: ts=4 expandtab syntax=python
 
=== modified file 'curtin/block/__init__.py'
--- curtin/block/__init__.py	2016-10-03 18:00:41 +0000
+++ curtin/block/__init__.py	2016-10-03 18:55:20 +0000
@@ -23,21 +23,31 @@
 import itertools
 
 from curtin import util
+from curtin.block import lvm
+from curtin.log import LOG
 from curtin.udev import udevadm_settle
-from curtin.log import LOG
 
 
 def get_dev_name_entry(devname):
+    """
+    convert device name to path in /dev
+    """
     bname = devname.split('/dev/')[-1]
     return (bname, "/dev/" + bname)
 
 
 def is_valid_device(devname):
+    """
+    check if device is a valid device
+    """
     devent = get_dev_name_entry(devname)[1]
     return is_block_device(devent)
 
 
 def is_block_device(path):
+    """
+    check if path is a block device
+    """
     try:
         return stat.S_ISBLK(os.stat(path).st_mode)
     except OSError as e:
@@ -47,26 +57,99 @@
 
 
 def dev_short(devname):
+    """
+    get short form of device name
+    """
+    devname = os.path.normpath(devname)
     if os.path.sep in devname:
         return os.path.basename(devname)
     return devname
 
 
 def dev_path(devname):
+    """
+    convert device name to path in /dev
+    """
     if devname.startswith('/dev/'):
         return devname
     else:
         return '/dev/' + devname
 
 
+def path_to_kname(path):
+    """
+    converts a path in /dev or a path in /sys/block to the device kname,
+    taking special devices and unusual naming schemes into account
+    """
+    # if path given is a link, get real path
+    # only do this if given a path though, if kname is already specified then
+    # this would cause a failure where the function should still be able to run
+    if os.path.sep in path:
+        path = os.path.realpath(path)
+    # using basename here ensures that the function will work given a path in
+    # /dev, a kname, or a path in /sys/block as an arg
+    dev_kname = os.path.basename(path)
+    # cciss devices need to have 'cciss!' prepended
+    if path.startswith('/dev/cciss'):
+        dev_kname = 'cciss!' + dev_kname
+    LOG.debug("path_to_kname input: '{}' output: '{}'".format(path, dev_kname))
+    return dev_kname
+
+
+def kname_to_path(kname):
+    """
+    converts a kname to a path in /dev, taking special devices and unusual
+    naming schemes into account
+    """
+    # if given something that is already a dev path, return it
+    if os.path.exists(kname) and is_valid_device(kname):
+        path = kname
+        LOG.debug("kname_to_path input: '{}' output: '{}'".format(kname, path))
+        return os.path.realpath(path)
+    # adding '/dev' to path is not sufficient to handle cciss devices and
+    # possibly other special devices which have not been encountered yet
+    path = os.path.realpath(os.sep.join(['/dev'] + kname.split('!')))
+    # make sure path we get is correct
+    if not (os.path.exists(path) and is_valid_device(path)):
+        raise OSError('could not get path to dev from kname: {}'.format(kname))
+    LOG.debug("kname_to_path input: '{}' output: '{}'".format(kname, path))
+    return path
+
+
+def partition_kname(disk_kname, partition_number):
+    """
+    Add number to disk_kname prepending a 'p' if needed
+    """
+    for dev_type in ['nvme', 'mmcblk', 'cciss', 'mpath', 'dm']:
+        if disk_kname.startswith(dev_type):
+            partition_number = "p%s" % partition_number
+            break
+    return "%s%s" % (disk_kname, partition_number)
+
+
+def sysfs_to_devpath(sysfs_path):
+    """
+    convert a path in /sys/class/block to a path in /dev
+    """
+    path = kname_to_path(path_to_kname(sysfs_path))
+    if not is_block_device(path):
+        raise ValueError('could not find blockdev for sys path: {}'
+                         .format(sysfs_path))
+    return path
+
+
 def sys_block_path(devname, add=None, strict=True):
+    """
+    get path to device in /sys/class/block
+    """
     toks = ['/sys/class/block']
     # insert parent dev if devname is partition
+    devname = os.path.normpath(devname)
     (parent, partnum) = get_blockdev_for_partition(devname)
     if partnum:
-        toks.append(dev_short(parent))
+        toks.append(path_to_kname(parent))
 
-    toks.append(dev_short(devname))
+    toks.append(path_to_kname(devname))
 
     if add is not None:
         toks.append(add)
@@ -83,6 +166,9 @@
 
 
 def _lsblock_pairs_to_dict(lines):
+    """
+    parse lsblock output and convert to dict
+    """
     ret = {}
     for line in lines.splitlines():
         toks = shlex.split(line)
@@ -98,6 +184,9 @@
 
 
 def _lsblock(args=None):
+    """
+    get lsblock data as dict
+    """
     # lsblk  --help | sed -n '/Available/,/^$/p' |
     #     sed -e 1d -e '$d' -e 's,^[ ]\+,,' -e 's, .*,,' | sort
     keys = ['ALIGNMENT', 'DISC-ALN', 'DISC-GRAN', 'DISC-MAX', 'DISC-ZERO',
@@ -120,8 +209,10 @@
 
 
 def get_unused_blockdev_info():
-    # return a list of unused block devices. These are devices that
-    # do not have anything mounted on them.
+    """
+    return a list of unused block devices.
+    These are devices that do not have anything mounted on them.
+    """
 
     # get a list of top level block devices, then iterate over it to get
     # devices dependent on those.  If the lsblk call for that specific
@@ -137,7 +228,9 @@
 
 
 def get_devices_for_mp(mountpoint):
-    # return a list of devices (full paths) used by the provided mountpoint
+    """
+    return a list of devices (full paths) used by the provided mountpoint
+    """
     bdinfo = _lsblock()
     found = set()
     for devname, data in bdinfo.items():
@@ -158,6 +251,9 @@
 
 
 def get_installable_blockdevs(include_removable=False, min_size=1024**3):
+    """
+    find blockdevs suitable for installation
+    """
     good = []
     unused = get_unused_blockdev_info()
     for devname, data in unused.items():
@@ -172,21 +268,25 @@
 
 
 def get_blockdev_for_partition(devpath):
+    """
+    find the parent device for a partition.
+    returns a tuple of the parent block device and the partition number
+    if device is not a partition, None will be returned for partition number
+    """
+    # normalize path
+    rpath = os.path.realpath(devpath)
+
     # convert an entry in /dev/ to parent disk and partition number
     # if devpath is a block device and not a partition, return (devpath, None)
-
-    # input of /dev/vdb or /dev/disk/by-label/foo
-    # rpath is hopefully a real-ish path in /dev (vda, sdb..)
-    rpath = os.path.realpath(devpath)
-
-    bname = os.path.basename(rpath)
-    syspath = "/sys/class/block/%s" % bname
-
+    base = '/sys/class/block'
+
+    # input of /dev/vdb, /dev/disk/by-label/foo, /sys/block/foo,
+    # /sys/block/class/foo, or just foo
+    syspath = os.path.join(base, path_to_kname(devpath))
+
+    # don't need to try out multiple sysfs paths as path_to_kname handles cciss
     if not os.path.exists(syspath):
-        syspath2 = "/sys/class/block/cciss!%s" % bname
-        if not os.path.exists(syspath2):
-            raise ValueError("%s had no syspath (%s)" % (devpath, syspath))
-        syspath = syspath2
+        raise OSError("%s had no syspath (%s)" % (devpath, syspath))
 
     ptpath = os.path.join(syspath, "partition")
     if not os.path.exists(ptpath):
@@ -207,8 +307,21 @@
     return (diskdevpath, ptnum)
 
 
+def get_sysfs_partitions(device):
+    """
+    get a list of sysfs paths for partitions under a block device
+    accepts input as a device kname, sysfs path, or dev path
+    returns empty list if no partitions available
+    """
+    sysfs_path = sys_block_path(device)
+    return [sys_block_path(kname) for kname in os.listdir(sysfs_path)
+            if os.path.exists(os.path.join(sysfs_path, kname, 'partition'))]
+
+
 def get_pardevs_on_blockdevs(devs):
-    # return a dict of partitions with their info that are on provided devs
+    """
+    return a dict of partitions with their info that are on provided devs
+    """
     if devs is None:
         devs = []
     devs = [get_dev_name_entry(d)[1] for d in devs]
@@ -243,7 +356,9 @@
 
 
 def rescan_block_devices():
-    # run 'blockdev --rereadpt' for all block devices not currently mounted
+    """
+    run 'blockdev --rereadpt' for all block devices not currently mounted
+    """
     unused = get_unused_blockdev_info()
     devices = []
     for devname, data in unused.items():
@@ -271,6 +386,9 @@
 
 
 def blkid(devs=None, cache=True):
+    """
+    get data about block devices from blkid and convert to dict
+    """
     if devs is None:
         devs = []
 
@@ -423,7 +541,18 @@
     """
     info = _lsblock([devpath])
     LOG.debug('get_blockdev_sector_size: info:\n%s' % util.json_dumps(info))
-    [parent] = info
+    # (LP: 1598310) The call to _lsblock() may return multiple results.
+    # If it does, then search for a result with the correct device path.
+    # If no such device is found among the results, then fall back to previous
+    # behavior, which was taking the first of the results
+    assert len(info) > 0
+    for (k, v) in info.items():
+        if v.get('device_path') == devpath:
+            parent = k
+            break
+    else:
+        parent = list(info.keys())[0]
+
     return (int(info[parent]['LOG-SEC']), int(info[parent]['PHY-SEC']))
 
 
@@ -499,50 +628,108 @@
 def sysfs_partition_data(blockdev=None, sysfs_path=None):
     # given block device or sysfs_path, return a list of tuples
     # of (kernel_name, number, offset, size)
-    if blockdev is None and sysfs_path is None:
-        raise ValueError("Blockdev and sysfs_path cannot both be None")
-
     if blockdev:
+        blockdev = os.path.normpath(blockdev)
         sysfs_path = sys_block_path(blockdev)
-
-    ptdata = []
-    # /sys/class/block/dev has entries of 'kname' for each partition
+    elif sysfs_path:
+        # use normpath to ensure that paths with trailing slash work
+        sysfs_path = os.path.normpath(sysfs_path)
+        blockdev = os.path.join('/dev', os.path.basename(sysfs_path))
+    else:
+        raise ValueError("Blockdev and sysfs_path cannot both be None")
 
     # queue property is only on parent devices, ie, we can't read
     # /sys/class/block/vda/vda1/queue/* as queue is only on the
     # parent device
+    sysfs_prefix = sysfs_path
     (parent, partnum) = get_blockdev_for_partition(blockdev)
-    sysfs_prefix = sysfs_path
     if partnum:
         sysfs_prefix = sys_block_path(parent)
-
-    block_size = int(util.load_file(os.path.join(sysfs_prefix,
-                                    'queue/logical_block_size')))
-
-    block_size = int(
-        util.load_file(os.path.join(sysfs_path, 'queue/logical_block_size')))
+        partnum = int(partnum)
+
+    block_size = int(util.load_file(os.path.join(
+        sysfs_prefix, 'queue/logical_block_size')))
     unit = block_size
-    for d in os.listdir(sysfs_path):
-        partd = os.path.join(sysfs_path, d)
+
+    ptdata = []
+    for part_sysfs in get_sysfs_partitions(sysfs_prefix):
         data = {}
         for sfile in ('partition', 'start', 'size'):
-            dfile = os.path.join(partd, sfile)
+            dfile = os.path.join(part_sysfs, sfile)
             if not os.path.isfile(dfile):
                 continue
             data[sfile] = int(util.load_file(dfile))
-        if 'partition' not in data:
-            continue
-        ptdata.append((d, data['partition'], data['start'] * unit,
-                       data['size'] * unit,))
+        if partnum is None or data['partition'] == partnum:
+            ptdata.append((path_to_kname(part_sysfs), data['partition'],
+                           data['start'] * unit, data['size'] * unit,))
 
     return ptdata
 
 
+def get_part_table_type(device):
+    """
+    check the type of partition table present on the specified device
+    returns None if no ptable was present or device could not be read
+    """
+    # it is neccessary to look for the gpt signature first, then the dos
+    # signature, because a gpt formatted disk usually has a valid mbr to
+    # protect the disk from being modified by older partitioning tools
+    return ('gpt' if check_efi_signature(device) else
+            'dos' if check_dos_signature(device) else None)
+
+
+def check_dos_signature(device):
+    """
+    check if there is a dos partition table signature present on device
+    """
+    # the last 2 bytes of a dos partition table have the signature with the
+    # value 0xAA55. the dos partition table is always 0x200 bytes long, even if
+    # the underlying disk uses a larger logical block size, so the start of
+    # this signature must be at 0x1fe
+    # https://en.wikipedia.org/wiki/Master_boot_record#Sector_layout
+    return (is_block_device(device) and util.file_size(device) >= 0x200 and
+            (util.load_file(device, mode='rb', read_len=2, offset=0x1fe) ==
+             b'\x55\xAA'))
+
+
+def check_efi_signature(device):
+    """
+    check if there is a gpt partition table signature present on device
+    """
+    # the gpt partition table header is always on lba 1, regardless of the
+    # logical block size used by the underlying disk. therefore, a static
+    # offset cannot be used, the offset to the start of the table header is
+    # always the sector size of the disk
+    # the start of the gpt partition table header shoult have the signaure
+    # 'EFI PART'.
+    # https://en.wikipedia.org/wiki/GUID_Partition_Table
+    sector_size = get_blockdev_sector_size(device)[0]
+    return (is_block_device(device) and
+            util.file_size(device) >= 2 * sector_size and
+            (util.load_file(device, mode='rb', read_len=8,
+                            offset=sector_size) == b'EFI PART'))
+
+
+def is_extended_partition(device):
+    """
+    check if the specified device path is a dos extended partition
+    """
+    # an extended partition must be on a dos disk, must be a partition, must be
+    # within the first 4 partitions and will have a valid dos signature,
+    # because the format of the extended partition matches that of a real mbr
+    (parent_dev, part_number) = get_blockdev_for_partition(device)
+    return (get_part_table_type(parent_dev) in ['dos', 'msdos'] and
+            part_number is not None and int(part_number) <= 4 and
+            check_dos_signature(device))
+
+
 def wipe_file(path, reader=None, buflen=4 * 1024 * 1024):
-    # wipe the existing file at path.
-    #  if reader is provided, it will be called as a 'reader(buflen)'
-    #  to provide data for each write.  Otherwise, zeros are used.
-    #  writes will be done in size of buflen.
+    """
+    wipe the existing file at path.
+    if reader is provided, it will be called as a 'reader(buflen)'
+    to provide data for each write.  Otherwise, zeros are used.
+    writes will be done in size of buflen.
+    """
     if reader:
         readfunc = reader
     else:
@@ -551,13 +738,11 @@
         def readfunc(size):
             return buf
 
+    size = util.file_size(path)
+    LOG.debug("%s is %s bytes. wiping with buflen=%s",
+              path, size, buflen)
+
     with open(path, "rb+") as fp:
-        # get the size by seeking to end.
-        fp.seek(0, 2)
-        size = fp.tell()
-        LOG.debug("%s is %s bytes. wiping with buflen=%s",
-                  path, size, buflen)
-        fp.seek(0)
         while True:
             pbuf = readfunc(buflen)
             pos = fp.tell()
@@ -574,16 +759,18 @@
 
 
 def quick_zero(path, partitions=True):
-    # zero 1M at front, 1M at end, and 1M at front
-    # if this is a block device and partitions is true, then
-    # zero 1M at front and end of each partition.
+    """
+    zero 1M at front, 1M at end, and 1M at front
+    if this is a block device and partitions is true, then
+    zero 1M at front and end of each partition.
+    """
     buflen = 1024
     count = 1024
     zero_size = buflen * count
     offsets = [0, -zero_size]
     is_block = is_block_device(path)
     if not (is_block or os.path.isfile(path)):
-        raise ValueError("%s: not an existing file or block device")
+        raise ValueError("%s: not an existing file or block device", path)
 
     if partitions and is_block:
         ptdata = sysfs_partition_data(path)
@@ -596,6 +783,9 @@
 
 
 def zero_file_at_offsets(path, offsets, buflen=1024, count=1024, strict=False):
+    """
+    write zeros to file at specified offsets
+    """
     bmsg = "{path} (size={size}): "
     m_short = bmsg + "{tot} bytes from {offset} > size."
     m_badoff = bmsg + "invalid offset {offset}."
@@ -657,15 +847,13 @@
     if mode == "pvremove":
         # We need to use --force --force in case it's already in a volgroup and
         # pvremove doesn't want to remove it
-        cmds = []
-        cmds.append(["pvremove", "--force", "--force", "--yes", path])
-        cmds.append(["pvscan", "--cache"])
-        cmds.append(["vgscan", "--mknodes", "--cache"])
+
         # If pvremove is run and there is no label on the system,
         # then it exits with 5. That is also okay, because we might be
         # wiping something that is already blank
-        for cmd in cmds:
-            util.subp(cmd, rcs=[0, 5], capture=True)
+        util.subp(['pvremove', '--force', '--force', '--yes', path],
+                  rcs=[0, 5], capture=True)
+        lvm.lvm_scan()
     elif mode == "zero":
         wipe_file(path)
     elif mode == "random":
 
=== added file 'curtin/block/clear_holders.py'
--- curtin/block/clear_holders.py	1970-01-01 00:00:00 +0000
+++ curtin/block/clear_holders.py	2016-10-03 18:55:20 +0000
@@ -0,0 +1,387 @@
+#   Copyright (C) 2016 Canonical Ltd.
+#
+#   Author: Wesley Wiedenmeier <[e-mail]>
+#
+#   Curtin is free software: you can redistribute it and/or modify it under
+#   the terms of the GNU Affero General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   Curtin is distributed in the hope that it will be useful, but WITHOUT ANY
+#   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#   FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+#   more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with Curtin.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+This module provides a mechanism for shutting down virtual storage layers on
+top of a block device, making it possible to reuse the block device without
+having to reboot the system
+"""
+
+import os
+
+from curtin import (block, udev, util)
+from curtin.block import lvm
+from curtin.log import LOG
+
+
+def _define_handlers_registry():
+    """
+    returns instantiated dev_types
+    """
+    return {
+        'partition': {'shutdown': wipe_superblock,
+                      'ident': identify_partition},
+        'lvm': {'shutdown': shutdown_lvm, 'ident': identify_lvm},
+        'crypt': {'shutdown': shutdown_crypt, 'ident': identify_crypt},
+        'raid': {'shutdown': shutdown_mdadm, 'ident': identify_mdadm},
+        'bcache': {'shutdown': shutdown_bcache, 'ident': identify_bcache},
+        'disk': {'ident': lambda x: False, 'shutdown': wipe_superblock},
+    }
+
+
+def get_dmsetup_uuid(device):
+    """
+    get the dm uuid for a specified dmsetup device
+    """
+    blockdev = block.sysfs_to_devpath(device)
+    (out, _) = util.subp(['dmsetup', 'info', blockdev, '-C', '-o', 'uuid',
+                          '--noheadings'], capture=True)
+    return out.strip()
+
+
+def get_bcache_using_dev(device):
+    """
+    Get the /sys/fs/bcache/ path of the bcache volume using specified device
+    """
+    # FIXME: when block.bcache is written this should be moved there
+    sysfs_path = block.sys_block_path(device)
+    return os.path.realpath(os.path.join(sysfs_path, 'bcache', 'cache'))
+
+
+def shutdown_bcache(device):
+    """
+    Shut down bcache for specified bcache device
+    """
+    bcache_shutdown_message = ('shutdown_bcache running on {} has determined '
+                               'that the device has already been shut down '
+                               'during handling of another bcache dev. '
+                               'skipping'.format(device))
+    if not os.path.exists(device):
+        LOG.info(bcache_shutdown_message)
+        return
+
+    bcache_sysfs = get_bcache_using_dev(device)
+    if not os.path.exists(bcache_sysfs):
+        LOG.info(bcache_shutdown_message)
+        return
+
+    LOG.debug('stopping bcache at: %s', bcache_sysfs)
+    util.write_file(os.path.join(bcache_sysfs, 'stop'), '1', mode=None)
+
+
+def shutdown_lvm(device):
+    """
+    Shutdown specified lvm device.
+    """
+    device = block.sys_block_path(device)
+    # lvm devices have a dm directory that containes a file 'name' containing
+    # '{volume group}-{logical volume}'. The volume can be freed using lvremove
+    name_file = os.path.join(device, 'dm', 'name')
+    (vg_name, lv_name) = lvm.split_lvm_name(util.load_file(name_file))
+    # use two --force flags here in case the volume group that this lv is
+    # attached two has been damaged
+    LOG.debug('running lvremove on %s/%s', vg_name, lv_name)
+    util.subp(['lvremove', '--force', '--force',
+               '{}/{}'.format(vg_name, lv_name)], rcs=[0, 5])
+    # if that was the last lvol in the volgroup, get rid of volgroup
+    if len(lvm.get_lvols_in_volgroup(vg_name)) == 0:
+        util.subp(['vgremove', '--force', '--force', vg_name], rcs=[0, 5])
+    # refresh lvmetad
+    lvm.lvm_scan()
+
+
+def shutdown_crypt(device):
+    """
+    Shutdown specified cryptsetup device
+    """
+    blockdev = block.sysfs_to_devpath(device)
+    util.subp(['cryptsetup', 'remove', blockdev], capture=True)
+
+
+def shutdown_mdadm(device):
+    """
+    Shutdown specified mdadm device.
+    """
+    blockdev = block.sysfs_to_devpath(device)
+    LOG.debug('using mdadm.mdadm_stop on dev: %s', blockdev)
+    block.mdadm.mdadm_stop(blockdev)
+    block.mdadm.mdadm_remove(blockdev)
+
+
+def wipe_superblock(device):
+    """
+    Wrapper for block.wipe_volume compatible with shutdown function interface
+    """
+    blockdev = block.sysfs_to_devpath(device)
+    # when operating on a disk that used to have a dos part table with an
+    # extended partition, attempting to wipe the extended partition will fail
+    if block.is_extended_partition(blockdev):
+        LOG.info("extended partitions do not need wiping, so skipping: '%s'",
+                 blockdev)
+    else:
+        LOG.info('wiping superblock on %s', blockdev)
+        block.wipe_volume(blockdev, mode='superblock')
+
+
+def identify_lvm(device):
+    """
+    determine if specified device is a lvm device
+    """
+    return (block.path_to_kname(device).startswith('dm') and
+            get_dmsetup_uuid(device).startswith('LVM'))
+
+
+def identify_crypt(device):
+    """
+    determine if specified device is dm-crypt device
+    """
+    return (block.path_to_kname(device).startswith('dm') and
+            get_dmsetup_uuid(device).startswith('CRYPT'))
+
+
+def identify_mdadm(device):
+    """
+    determine if specified device is a mdadm device
+    """
+    return block.path_to_kname(device).startswith('md')
+
+
+def identify_bcache(device):
+    """
+    determine if specified device is a bcache device
+    """
+    return block.path_to_kname(device).startswith('bcache')
+
+
+def identify_partition(device):
+    """
+    determine if specified device is a partition
+    """
+    path = os.path.join(block.sys_block_path(device), 'partition')
+    return os.path.exists(path)
+
+
+def get_holders(device):
+    """
+    Look up any block device holders, return list of knames
+    """
+    # block.sys_block_path works when given a /sys or /dev path
+    sysfs_path = block.sys_block_path(device)
+    # get holders
+    holders = os.listdir(os.path.join(sysfs_path, 'holders'))
+    LOG.debug("devname '%s' had holders: %s", device, holders)
+    return holders
+
+
+def gen_holders_tree(device):
+    """
+    generate a tree representing the current storage hirearchy above 'device'
+    """
+    device = block.sys_block_path(device)
+    dev_name = block.path_to_kname(device)
+    # the holders for a device should consist of the devices in the holders/
+    # dir in sysfs and any partitions on the device. this ensures that a
+    # storage tree starting from a disk will include all devices holding the
+    # disk's partitions
+    holder_paths = ([block.sys_block_path(h) for h in get_holders(device)] +
+                    block.get_sysfs_partitions(device))
+    # the DEV_TYPE registry contains a function under the key 'ident' for each
+    # device type entry that returns true if the device passed to it is of the
+    # correct type. there should never be a situation in which multiple
+    # identify functions return true. therefore, it will always work to take
+    # the device type with the first identify function that returns true as the
+    # device type for the current device. in the event that no identify
+    # functions return true, the device will be treated as a disk
+    # (DEFAULT_DEV_TYPE). the identify function for disk never returns true.
+    # the next() builtin in python will not raise a StopIteration exception if
+    # there is a default value defined
+    dev_type = next((k for k, v in DEV_TYPES.items() if v['ident'](device)),
+                    DEFAULT_DEV_TYPE)
+    return {
+        'device': device, 'dev_type': dev_type, 'name': dev_name,
+        'holders': [gen_holders_tree(h) for h in holder_paths],
+    }
+
+
+def plan_shutdown_holder_trees(holders_trees):
+    """
+    plan best order to shut down holders in, taking into account high level
+    storage layers that may have many devices below them
+
+    returns a sorted list of descriptions of storage config entries including
+    their path in /sys/block and their dev type
+
+    can accept either a single storage tree or a list of storage trees assumed
+    to start at an equal place in storage hirearchy (i.e. a list of trees
+    starting from disk)
+    """
+    # holds a temporary registry of holders to allow cross references
+    # key = device sysfs path, value = {} of priority level, shutdown function
+    reg = {}
+
+    # normalize to list of trees
+    if not isinstance(holders_trees, (list, tuple)):
+        holders_trees = [holders_trees]
+
+    def flatten_holders_tree(tree, level=0):
+        """
+        add entries from holders tree to registry with level key corresponding
+        to how many layers from raw disks the current device is at
+        """
+        device = tree['device']
+
+        # always go with highest level if current device has been
+        # encountered already. since the device and everything above it is
+        # re-added to the registry it ensures that any increase of level
+        # required here will propagate down the tree
+        # this handles a scenario like mdadm + bcache, where the backing
+        # device for bcache is a 3nd level item like mdadm, but the cache
+        # device is 1st level (disk) or second level (partition), ensuring
+        # that the bcache item is always considered higher level than
+        # anything else regardless of whether it was added to the tree via
+        # the cache device or backing device first
+        if device in reg:
+            level = max(reg[device]['level'], level)
+
+        reg[device] = {'level': level, 'device': device,
+                       'dev_type': tree['dev_type']}
+
+        # handle holders above this level
+        for holder in tree['holders']:
+            flatten_holders_tree(holder, level=level + 1)
+
+    # flatten the holders tree into the registry
+    for holders_tree in holders_trees:
+        flatten_holders_tree(holders_tree)
+
+    # return list of entry dicts with highest level first
+    return [reg[k] for k in sorted(reg, key=lambda x: reg[x]['level'] * -1)]
+
+
+def format_holders_tree(holders_tree):
+    """
+    draw a nice dirgram of the holders tree
+    """
+    # spacer styles based on output of 'tree --charset=ascii'
+    spacers = (('`-- ', ' ' * 4), ('|-- ', '|' + ' ' * 3))
+
+    def format_tree(tree):
+        """
+        format entry and any subentries
+        """
+        result = [tree['name']]
+        holders = tree['holders']
+        for (holder_no, holder) in enumerate(holders):
+            spacer_style = spacers[min(len(holders) - (holder_no + 1), 1)]
+            subtree_lines = format_tree(holder)
+            for (line_no, line) in enumerate(subtree_lines):
+                result.append(spacer_style[min(line_no, 1)] + line)
+        return result
+
+    return '\n'.join(format_tree(holders_tree))
+
+
+def get_holder_types(tree):
+    """
+    get flattened list of types of holders in holders tree and the devices
+    they correspond to
+    """
+    types = {(tree['dev_type'], tree['device'])}
+    for holder in tree['holders']:
+        types.update(get_holder_types(holder))
+    return types
+
+
+def assert_clear(base_paths):
+    """
+    Check if all paths in base_paths are clear to use
+    """
+    valid = ('disk', 'partition')
+    if not isinstance(base_paths, (list, tuple)):
+        base_paths = [base_paths]
+    base_paths = [block.sys_block_path(path) for path in base_paths]
+    for holders_tree in [gen_holders_tree(p) for p in base_paths]:
+        if any(holder_type not in valid and path not in base_paths
+               for (holder_type, path) in get_holder_types(holders_tree)):
+            raise OSError('Storage not clear, remaining:\n{}'
+                          .format(format_holders_tree(holders_tree)))
+
+
+def clear_holders(base_paths, try_preserve=False):
+    """
+    Clear all storage layers depending on the devices specified in 'base_paths'
+    A single device or list of devices can be specified.
+    Device paths can be specified either as paths in /dev or /sys/block
+    Will throw OSError if any holders could not be shut down
+    """
+    # handle single path
+    if not isinstance(base_paths, (list, tuple)):
+        base_paths = [base_paths]
+
+    # get current holders and plan how to shut them down
+    holder_trees = [gen_holders_tree(path) for path in base_paths]
+    LOG.info('Current device storage tree:\n%s',
+             '\n'.join(format_holders_tree(tree) for tree in holder_trees))
+    ordered_devs = plan_shutdown_holder_trees(holder_trees)
+
+    # run shutdown functions
+    for dev_info in ordered_devs:
+        dev_type = DEV_TYPES.get(dev_info['dev_type'])
+        shutdown_function = dev_type.get('shutdown')
+        if not shutdown_function:
+            continue
+        if try_preserve and shutdown_function in DATA_DESTROYING_HANDLERS:
+            LOG.info('shutdown function for holder type: %s is destructive. '
+                     'attempting to preserve data, so not skipping' %
+                     dev_info['dev_type'])
+            continue
+        LOG.info("shutdown running on holder type: '%s' syspath: '%s'",
+                 dev_info['dev_type'], dev_info['device'])
+        shutdown_function(dev_info['device'])
+        udev.udevadm_settle()
+
+
+def start_clear_holders_deps():
+    """
+    prepare system for clear holders to be able to scan old devices
+    """
+    # a mdadm scan has to be started in case there is a md device that needs to
+    # be detected. if the scan fails, it is either because there are no mdadm
+    # devices on the system, or because there is a mdadm device in a damaged
+    # state that could not be started. due to the nature of mdadm tools, it is
+    # difficult to know which is the case. if any errors did occur, then ignore
+    # them, since no action needs to be taken if there were no mdadm devices on
+    # the system, and in the case where there is some mdadm metadata on a disk,
+    # but there was not enough to start the array, the call to wipe_volume on
+    # all disks and partitions should be sufficient to remove the mdadm
+    # metadata
+    block.mdadm.mdadm_assemble(scan=True, ignore_errors=True)
+    # the bcache module needs to be present to properly detect bcache devs
+    # on some systems (precise without hwe kernel) it may not be possible to
+    # lad the bcache module bcause it is not present in the kernel. if this
+    # happens then there is no need to halt installation, as the bcache devices
+    # will never appear and will never prevent the disk from being reformatted
+    util.subp(['modprobe', 'bcache'], rcs=[0, 1])
+
+
+# anything that is not identified can assumed to be a 'disk' or similar
+DEFAULT_DEV_TYPE = 'disk'
+# handlers that should not be run if an attempt is being made to preserve data
+DATA_DESTROYING_HANDLERS = [wipe_superblock]
+# types of devices that could be encountered by clear holders and functions to
+# identify them and shut them down
+DEV_TYPES = _define_handlers_registry()
 
=== added file 'curtin/block/lvm.py'
--- curtin/block/lvm.py	1970-01-01 00:00:00 +0000
+++ curtin/block/lvm.py	2016-10-03 18:55:20 +0000
@@ -0,0 +1,96 @@
+#   Copyright (C) 2016 Canonical Ltd.
+#
+#   Author: Wesley Wiedenmeier <[e-mail]>
+#
+#   Curtin is free software: you can redistribute it and/or modify it under
+#   the terms of the GNU Affero General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   Curtin is distributed in the hope that it will be useful, but WITHOUT ANY
+#   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#   FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+#   more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with Curtin.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+This module provides some helper functions for manipulating lvm devices
+"""
+
+from curtin import util
+from curtin.log import LOG
+import os
+
+# separator to use for lvm/dm tools
+_SEP = '='
+
+
+def _filter_lvm_info(lvtool, match_field, query_field, match_key):
+    """
+    filter output of pv/vg/lvdisplay tools
+    """
+    (out, _) = util.subp([lvtool, '-C', '--separator', _SEP, '--noheadings',
+                          '-o', ','.join([match_field, query_field])],
+                         capture=True)
+    return [qf for (mf, qf) in
+            [l.strip().split(_SEP) for l in out.strip().splitlines()]
+            if mf == match_key]
+
+
+def get_pvols_in_volgroup(vg_name):
+    """
+    get physical volumes used by volgroup
+    """
+    return _filter_lvm_info('pvdisplay', 'vg_name', 'pv_name', vg_name)
+
+
+def get_lvols_in_volgroup(vg_name):
+    """
+    get logical volumes in volgroup
+    """
+    return _filter_lvm_info('lvdisplay', 'vg_name', 'lv_name', vg_name)
+
+
+def split_lvm_name(full):
+    """
+    split full lvm name into tuple of (volgroup, lv_name)
+    """
+    # 'dmsetup splitname' is the authoratative source for lvm name parsing
+    (out, _) = util.subp(['dmsetup', 'splitname', full, '-c', '--noheadings',
+                          '--separator', _SEP, '-o', 'vg_name,lv_name'],
+                         capture=True)
+    return out.strip().split(_SEP)
+
+
+def lvmetad_running():
+    """
+    check if lvmetad is running
+    """
+    return os.path.exists(os.environ.get('LVM_LVMETAD_PIDFILE',
+                                         '/run/lvmetad.pid'))
+
+
+def lvm_scan():
+    """
+    run full scan for volgroups, logical volumes and physical volumes
+    """
+    # the lvm tools lvscan, vgscan and pvscan on ubuntu precise do not
+    # support the flag --cache. the flag is present for the tools in ubuntu
+    # trusty and later. since lvmetad is used in current releases of
+    # ubuntu, the --cache flag is needed to ensure that the data cached by
+    # lvmetad is updated.
+
+    # before appending the cache flag though, check if lvmetad is running. this
+    # ensures that we do the right thing even if lvmetad is supported but is
+    # not running
+    release = util.lsb_release().get('codename')
+    if release in [None, 'UNAVAILABLE']:
+        LOG.warning('unable to find release number, assuming xenial or later')
+        release = 'xenial'
+
+    for cmd in [['pvscan'], ['vgscan', '--mknodes']]:
+        if release != 'precise' and lvmetad_running():
+            cmd.append('--cache')
+        util.subp(cmd, capture=True)
 
=== modified file 'curtin/block/mdadm.py'
--- curtin/block/mdadm.py	2016-05-10 16:13:29 +0000
+++ curtin/block/mdadm.py	2016-10-03 18:55:20 +0000
@@ -28,7 +28,7 @@
 from subprocess import CalledProcessError
 
 from curtin.block import (dev_short, dev_path, is_valid_device, sys_block_path)
-from curtin import util
+from curtin import (util, udev)
 from curtin.log import LOG
 
 NOSPARE_RAID_LEVELS = [
@@ -117,21 +117,34 @@
 #
 
 
-def mdadm_assemble(md_devname=None, devices=[], spares=[], scan=False):
+def mdadm_assemble(md_devname=None, devices=[], spares=[], scan=False,
+                   ignore_errors=False):
     # md_devname is a /dev/XXXX
     # devices is non-empty list of /dev/xxx
     # if spares is non-empt list append of /dev/xxx
     cmd = ["mdadm", "--assemble"]
     if scan:
-        cmd += ['--scan']
+        cmd += ['--scan', '-v']
     else:
         valid_mdname(md_devname)
         cmd += [md_devname, "--run"] + devices
         if spares:
             cmd += spares
 
-    util.subp(cmd, capture=True, rcs=[0, 1, 2])
-    util.subp(["udevadm", "settle"])
+    try:
+        # mdadm assemble returns 1 when no arrays are found. this might not be
+        # an error depending on the situation this function was called in, so
+        # accept a return code of 1
+        # mdadm assemble returns 2 when called on an array that is already
+        # assembled. this is not an error, so accept return code of 2
+        # all other return codes can be accepted with ignore_error set to true
+        util.subp(cmd, capture=True, rcs=[0, 1, 2])
+    except util.ProcessExecutionError:
+        LOG.warning("mdadm_assemble had unexpected return code")
+        if not ignore_errors:
+            raise
+
+    udev.udevadm_settle()
 
 
 def mdadm_create(md_devname, raidlevel, devices, spares=None, md_name=""):
 
=== modified file 'curtin/block/mkfs.py'
--- curtin/block/mkfs.py	2016-05-10 16:13:29 +0000
+++ curtin/block/mkfs.py	2016-10-03 18:55:20 +0000
@@ -78,6 +78,7 @@
              "swap": "--uuid"},
     "force": {"btrfs": "--force",
               "ext": "-F",
+              "fat": "-I",
               "ntfs": "--force",
               "reiserfs": "-f",
               "swap": "--force",
@@ -91,6 +92,7 @@
         "btrfs": "--sectorsize",
         "ext": "-b",
         "fat": "-S",
+        "xfs": "-s",
         "ntfs": "--sector-size",
         "reiserfs": "--block-size"}
 }
@@ -165,12 +167,15 @@
     # use device logical block size to ensure properly formated filesystems
     (logical_bsize, physical_bsize) = block.get_blockdev_sector_size(path)
     if logical_bsize > 512:
+        lbs_str = ('size={}'.format(logical_bsize) if fs_family == "xfs"
+                   else str(logical_bsize))
         cmd.extend(get_flag_mapping("sectorsize", fs_family,
-                                    param=str(logical_bsize),
-                                    strict=strict))
-        # mkfs.vfat doesn't calculate this right for non-512b sector size
-        # lp:1569576 , d-i uses the same setting.
-        cmd.extend(["-s", "1"])
+                                    param=lbs_str, strict=strict))
+
+        if fs_family == 'fat':
+            # mkfs.vfat doesn't calculate this right for non-512b sector size
+            # lp:1569576 , d-i uses the same setting.
+            cmd.extend(["-s", "1"])
 
     if force:
         cmd.extend(get_flag_mapping("force", fs_family, strict=strict))
 
=== modified file 'curtin/commands/apply_net.py'
--- curtin/commands/apply_net.py	2016-05-10 16:13:29 +0000
+++ curtin/commands/apply_net.py	2016-10-03 18:55:20 +0000
@@ -26,6 +26,57 @@
 
 LOG = log.LOG
 
+IFUPDOWN_IPV6_MTU_PRE_HOOK = """#!/bin/bash -e
+# injected by curtin installer
+
+[ "${IFACE}" != "lo" ] || exit 0
+
+# Trigger only if MTU configured
+[ -n "${IF_MTU}" ] || exit 0
+
+read CUR_DEV_MTU </sys/class/net/${IFACE}/mtu ||:
+read CUR_IPV6_MTU </proc/sys/net/ipv6/conf/${IFACE}/mtu ||:
+[ -n "${CUR_DEV_MTU}" ] && echo ${CUR_DEV_MTU} > /run/network/${IFACE}_dev.mtu
+[ -n "${CUR_IPV6_MTU}" ] &&
+  echo ${CUR_IPV6_MTU} > /run/network/${IFACE}_ipv6.mtu
+exit 0
+"""
+
+IFUPDOWN_IPV6_MTU_POST_HOOK = """#!/bin/bash -e
+# injected by curtin installer
+
+[ "${IFACE}" != "lo" ] || exit 0
+
+# Trigger only if MTU configured
+[ -n "${IF_MTU}" ] || exit 0
+
+read PRE_DEV_MTU </run/network/${IFACE}_dev.mtu ||:
+read CUR_DEV_MTU </sys/class/net/${IFACE}/mtu ||:
+read PRE_IPV6_MTU </run/network/${IFACE}_ipv6.mtu ||:
+read CUR_IPV6_MTU </proc/sys/net/ipv6/conf/${IFACE}/mtu ||:
+
+if [ "${ADDRFAM}" = "inet6" ]; then
+  # We need to check the underlying interface MTU and
+  # raise it if the IPV6 mtu is larger
+  if [ ${CUR_DEV_MTU} -lt ${IF_MTU} ]; then
+      ip link set ${IFACE} mtu ${IF_MTU}
+  fi
+  # sysctl -q -e -w net.ipv6.conf.${IFACE}.mtu=${IF_MTU}
+  echo ${IF_MTU} >/proc/sys/net/ipv6/conf/${IFACE}/mtu ||:
+
+elif [ "${ADDRFAM}" = "inet" ]; then
+  # handle the clobber case where inet mtu changes v6 mtu.
+  # ifupdown will already have set dev mtu, so lower mtu
+  # if needed.  If v6 mtu was larger, it get's clamped down
+  # to the dev MTU value.
+  if [ ${PRE_IPV6_MTU} -lt ${CUR_IPV6_MTU} ]; then
+    # sysctl -q -e -w net.ipv6.conf.${IFACE}.mtu=${PRE_IPV6_MTU}
+    echo ${PRE_IPV6_MTU} >/proc/sys/net/ipv6/conf/${IFACE}/mtu ||:
+  fi
+fi
+exit 0
+"""
+
 
 def apply_net(target, network_state=None, network_config=None):
     if network_state is None and network_config is None:
@@ -45,6 +96,108 @@
 
     net.render_network_state(target=target, network_state=ns)
 
+    _maybe_remove_legacy_eth0(target)
+    LOG.info('Attempting to remove ipv6 privacy extensions')
+    _disable_ipv6_privacy_extensions(target)
+    _patch_ifupdown_ipv6_mtu_hook(target)
+
+
+def _patch_ifupdown_ipv6_mtu_hook(target,
+                                  prehookfn="etc/network/if-pre-up.d/mtuipv6",
+                                  posthookfn="etc/network/if-up.d/mtuipv6"):
+
+    contents = {
+        'prehook': IFUPDOWN_IPV6_MTU_PRE_HOOK,
+        'posthook': IFUPDOWN_IPV6_MTU_POST_HOOK,
+    }
+
+    hookfn = {
+        'prehook': prehookfn,
+        'posthook': posthookfn,
+    }
+
+    for hook in ['prehook', 'posthook']:
+        fn = hookfn[hook]
+        cfg = util.target_path(target, path=fn)
+        LOG.info('Injecting fix for ipv6 mtu settings: %s', cfg)
+        util.write_file(cfg, contents[hook], mode=0o755)
+
+
+def _disable_ipv6_privacy_extensions(target,
+                                     path="etc/sysctl.d/10-ipv6-privacy.conf"):
+
+    """Ubuntu server image sets a preference to use IPv6 privacy extensions
+       by default; this races with the cloud-image desire to disable them.
+       Resolve this by allowing the cloud-image setting to win. """
+
+    cfg = util.target_path(target, path=path)
+    if not os.path.exists(cfg):
+        LOG.warn('Failed to find ipv6 privacy conf file %s', cfg)
+        return
+
+    bmsg = "Disabling IPv6 privacy extensions config may not apply."
+    try:
+        contents = util.load_file(cfg)
+        known_contents = ["net.ipv6.conf.all.use_tempaddr = 2",
+                          "net.ipv6.conf.default.use_tempaddr = 2"]
+        lines = [f.strip() for f in contents.splitlines()
+                 if not f.startswith("#")]
+        if lines == known_contents:
+            LOG.info('deleting file: %s', cfg)
+            util.del_file(cfg)
+            msg = "removed %s with known contents" % cfg
+            curtin_contents = '\n'.join(
+                ["# IPv6 Privacy Extensions (RFC 4941)",
+                 "# Disabled by curtin",
+                 "# net.ipv6.conf.all.use_tempaddr = 2",
+                 "# net.ipv6.conf.default.use_tempaddr = 2"])
+            util.write_file(cfg, curtin_contents)
+        else:
+            LOG.info('skipping, content didnt match')
+            LOG.debug("found content:\n%s", lines)
+            LOG.debug("expected contents:\n%s", known_contents)
+            msg = (bmsg + " '%s' exists with user configured content." % cfg)
+    except:
+        msg = bmsg + " %s exists, but could not be read." % cfg
+        LOG.exception(msg)
+        return
+
+
+def _maybe_remove_legacy_eth0(target,
+                              path="etc/network/interfaces.d/eth0.cfg"):
+    """Ubuntu cloud images previously included a 'eth0.cfg' that had
+       hard coded content.  That file would interfere with the rendered
+       configuration if it was present.
+
+       if the file does not exist do nothing.
+       If the file exists:
+         - with known content, remove it and warn
+         - with unknown content, leave it and warn
+    """
+
+    cfg = util.target_path(target, path=path)
+    if not os.path.exists(cfg):
+        LOG.warn('Failed to find legacy network conf file %s', cfg)
+        return
+
+    bmsg = "Dynamic networking config may not apply."
+    try:
+        contents = util.load_file(cfg)
+        known_contents = ["auto eth0", "iface eth0 inet dhcp"]
+        lines = [f.strip() for f in contents.splitlines()
+                 if not f.startswith("#")]
+        if lines == known_contents:
+            util.del_file(cfg)
+            msg = "removed %s with known contents" % cfg
+        else:
+            msg = (bmsg + " '%s' exists with user configured content." % cfg)
+    except:
+        msg = bmsg + " %s exists, but could not be read." % cfg
+        LOG.exception(msg)
+        return
+
+    LOG.warn(msg)
+
 
 def apply_net_main(args):
     #  curtin apply_net [--net-state=/config/netstate.yml] [--target=/]
@@ -76,8 +229,10 @@
         apply_net(target=state['target'],
                   network_state=state['network_state'],
                   network_config=state['network_config'])
+
     except Exception:
         LOG.exception('failed to apply network config')
+        return 1
 
     LOG.info('Applied network configuration successfully')
     sys.exit(0)
@@ -90,7 +245,7 @@
       'metavar': 'NETSTATE', 'action': 'store',
       'default': os.environ.get('OUTPUT_NETWORK_STATE')}),
      (('-t', '--target'),
-      {'help': ('target filesystem root to add swap file to. '
+      {'help': ('target filesystem root to configure networking to. '
                 'default is env["TARGET_MOUNT_POINT"]'),
        'metavar': 'TARGET', 'action': 'store',
        'default': os.environ.get('TARGET_MOUNT_POINT')}),
 
=== added file 'curtin/commands/apt_config.py'
--- curtin/commands/apt_config.py	1970-01-01 00:00:00 +0000
+++ curtin/commands/apt_config.py	2016-10-03 18:55:20 +0000
@@ -0,0 +1,668 @@
+#   Copyright (C) 2016 Canonical Ltd.
+#
+#   Author: Christian Ehrhardt <[e-mail]>
+#
+#   Curtin is free software: you can redistribute it and/or modify it under
+#   the terms of the GNU Affero General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   Curtin is distributed in the hope that it will be useful, but WITHOUT ANY
+#   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#   FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+#   more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with Curtin.  If not, see <http://www.gnu.org/licenses/>.
+"""
+apt.py
+Handle the setup of apt related tasks like proxies, mirrors, repositories.
+"""
+
+import argparse
+import glob
+import os
+import re
+import sys
+import yaml
+
+from curtin.log import LOG
+from curtin import (config, util, gpg)
+
+from . import populate_one_subcmd
+
+# this will match 'XXX:YYY' (ie, 'cloud-archive:foo' or 'ppa:bar')
+ADD_APT_REPO_MATCH = r"^[\w-]+:\w"
+
+# place where apt stores cached repository data
+APT_LISTS = "/var/lib/apt/lists"
+
+# Files to store proxy information
+APT_CONFIG_FN = "/etc/apt/apt.conf.d/94curtin-config"
+APT_PROXY_FN = "/etc/apt/apt.conf.d/90curtin-aptproxy"
+
+# Default keyserver to use
+DEFAULT_KEYSERVER = "keyserver.ubuntu.com"
+
+# Default archive mirrors
+PRIMARY_ARCH_MIRRORS = {"PRIMARY": "http://archive.ubuntu.com/ubuntu/",
+                        "SECURITY": "http://security.ubuntu.com/ubuntu/"}
+PORTS_MIRRORS = {"PRIMARY": "http://ports.ubuntu.com/ubuntu-ports",
+                 "SECURITY": "http://ports.ubuntu.com/ubuntu-ports"}
+PRIMARY_ARCHES = ['amd64', 'i386']
+PORTS_ARCHES = ['s390x', 'arm64', 'armhf', 'powerpc', 'ppc64el']
+
+
+def get_default_mirrors(arch=None):
+    """returns the default mirrors for the target. These depend on the
+       architecture, for more see:
+       https://wiki.ubuntu.com/UbuntuDevelopment/PackageArchive#Ports"""
+    if arch is None:
+        arch = util.get_architecture()
+    if arch in PRIMARY_ARCHES:
+        return PRIMARY_ARCH_MIRRORS.copy()
+    if arch in PORTS_ARCHES:
+        return PORTS_MIRRORS.copy()
+    raise ValueError("No default mirror known for arch %s" % arch)
+
+
+def handle_apt(cfg, target=None):
+    """ handle_apt
+        process the config for apt_config. This can be called from
+        curthooks if a global apt config was provided or via the "apt"
+        standalone command.
+    """
+    release = util.lsb_release(target=target)['codename']
+    arch = util.get_architecture(target)
+    mirrors = find_apt_mirror_info(cfg, arch)
+    LOG.debug("Apt Mirror info: %s", mirrors)
+
+    apply_debconf_selections(cfg, target)
+
+    if not config.value_as_boolean(cfg.get('preserve_sources_list',
+                                           True)):
+        generate_sources_list(cfg, release, mirrors, target)
+        rename_apt_lists(mirrors, target)
+
+    try:
+        apply_apt_proxy_config(cfg, target + APT_PROXY_FN,
+                               target + APT_CONFIG_FN)
+    except (IOError, OSError):
+        LOG.exception("Failed to apply proxy or apt config info:")
+
+    # Process 'apt_source -> sources {dict}'
+    if 'sources' in cfg:
+        params = mirrors
+        params['RELEASE'] = release
+        params['MIRROR'] = mirrors["MIRROR"]
+
+        matcher = None
+        matchcfg = cfg.get('add_apt_repo_match', ADD_APT_REPO_MATCH)
+        if matchcfg:
+            matcher = re.compile(matchcfg).search
+
+        add_apt_sources(cfg['sources'], target,
+                        template_params=params, aa_repo_match=matcher)
+
+
+def debconf_set_selections(selections, target=None):
+    util.subp(['debconf-set-selections'], data=selections, target=target,
+              capture=True)
+
+
+def dpkg_reconfigure(packages, target=None):
+    # For any packages that are already installed, but have preseed data
+    # we populate the debconf database, but the filesystem configuration
+    # would be preferred on a subsequent dpkg-reconfigure.
+    # so, what we have to do is "know" information about certain packages
+    # to unconfigure them.
+    unhandled = []
+    to_config = []
+    for pkg in packages:
+        if pkg in CONFIG_CLEANERS:
+            LOG.debug("unconfiguring %s", pkg)
+            CONFIG_CLEANERS[pkg](target)
+            to_config.append(pkg)
+        else:
+            unhandled.append(pkg)
+
+    if len(unhandled):
+        LOG.warn("The following packages were installed and preseeded, "
+                 "but cannot be unconfigured: %s", unhandled)
+
+    if len(to_config):
+        util.subp(['dpkg-reconfigure', '--frontend=noninteractive'] +
+                  list(to_config), data=None, target=target, capture=True)
+
+
+def apply_debconf_selections(cfg, target=None):
+    """apply_debconf_selections - push content to debconf"""
+    # debconf_selections:
+    #  set1: |
+    #   cloud-init cloud-init/datasources multiselect MAAS
+    #  set2: pkg pkg/value string bar
+    selsets = cfg.get('debconf_selections')
+    if not selsets:
+        LOG.debug("debconf_selections was not set in config")
+        return
+
+    selections = '\n'.join(
+        [selsets[key] for key in sorted(selsets.keys())])
+    debconf_set_selections(selections.encode() + b"\n", target=target)
+
+    # get a complete list of packages listed in input
+    pkgs_cfgd = set()
+    for key, content in selsets.items():
+        for line in content.splitlines():
+            if line.startswith("#"):
+                continue
+            pkg = re.sub(r"[:\s].*", "", line)
+            pkgs_cfgd.add(pkg)
+
+    pkgs_installed = util.get_installed_packages(target)
+
+    LOG.debug("pkgs_cfgd: %s", pkgs_cfgd)
+    LOG.debug("pkgs_installed: %s", pkgs_installed)
+    need_reconfig = pkgs_cfgd.intersection(pkgs_installed)
+
+    if len(need_reconfig) == 0:
+        LOG.debug("no need for reconfig")
+        return
+
+    dpkg_reconfigure(need_reconfig, target=target)
+
+
+def clean_cloud_init(target):
+    """clean out any local cloud-init config"""
+    flist = glob.glob(
+        util.target_path(target, "/etc/cloud/cloud.cfg.d/*dpkg*"))
+
+    LOG.debug("cleaning cloud-init config from: %s", flist)
+    for dpkg_cfg in flist:
+        os.unlink(dpkg_cfg)
+
+
+def mirrorurl_to_apt_fileprefix(mirror):
+    """ mirrorurl_to_apt_fileprefix
+        Convert a mirror url to the file prefix used by apt on disk to
+        store cache information for that mirror.
+        To do so do:
+        - take off ???://
+        - drop tailing /
+        - convert in string / to _
+    """
+    string = mirror
+    if string.endswith("/"):
+        string = string[0:-1]
+    pos = string.find("://")
+    if pos >= 0:
+        string = string[pos + 3:]
+    string = string.replace("/", "_")
+    return string
+
+
+def rename_apt_lists(new_mirrors, target=None):
+    """rename_apt_lists - rename apt lists to preserve old cache data"""
+    default_mirrors = get_default_mirrors(util.get_architecture(target))
+
+    pre = util.target_path(target, APT_LISTS)
+    for (name, omirror) in default_mirrors.items():
+        nmirror = new_mirrors.get(name)
+        if not nmirror:
+            continue
+
+        oprefix = pre + os.path.sep + mirrorurl_to_apt_fileprefix(omirror)
+        nprefix = pre + os.path.sep + mirrorurl_to_apt_fileprefix(nmirror)
+        if oprefix == nprefix:
+            continue
+        olen = len(oprefix)
+        for filename in glob.glob("%s_*" % oprefix):
+            newname = "%s%s" % (nprefix, filename[olen:])
+            LOG.debug("Renaming apt list %s to %s", filename, newname)
+            try:
+                os.rename(filename, newname)
+            except OSError:
+                # since this is a best effort task, warn with but don't fail
+                LOG.warn("Failed to rename apt list:", exc_info=True)
+
+
+def mirror_to_placeholder(tmpl, mirror, placeholder):
+    """ mirror_to_placeholder
+        replace the specified mirror in a template with a placeholder string
+        Checks for existance of the expected mirror and warns if not found
+    """
+    if mirror not in tmpl:
+        LOG.warn("Expected mirror '%s' not found in: %s", mirror, tmpl)
+    return tmpl.replace(mirror, placeholder)
+
+
+def map_known_suites(suite):
+    """there are a few default names which will be auto-extended.
+       This comes at the inability to use those names literally as suites,
+       but on the other hand increases readability of the cfg quite a lot"""
+    mapping = {'updates': '$RELEASE-updates',
+               'backports': '$RELEASE-backports',
+               'security': '$RELEASE-security',
+               'proposed': '$RELEASE-proposed',
+               'release': '$RELEASE'}
+    try:
+        retsuite = mapping[suite]
+    except KeyError:
+        retsuite = suite
+    return retsuite
+
+
+def disable_suites(disabled, src, release):
+    """reads the config for suites to be disabled and removes those
+       from the template"""
+    if not disabled:
+        return src
+
+    retsrc = src
+    for suite in disabled:
+        suite = map_known_suites(suite)
+        releasesuite = util.render_string(suite, {'RELEASE': release})
+        LOG.debug("Disabling suite %s as %s", suite, releasesuite)
+
+        newsrc = ""
+        for line in retsrc.splitlines(True):
+            if line.startswith("#"):
+                newsrc += line
+                continue
+
+            # sources.list allow options in cols[1] which can have spaces
+            # so the actual suite can be [2] or later. example:
+            # deb [ arch=amd64,armel k=v ] http://example.com/debian
+            cols = line.split()
+            if len(cols) > 1:
+                pcol = 2
+                if cols[1].startswith("["):
+                    for col in cols[1:]:
+                        pcol += 1
+                        if col.endswith("]"):
+                            break
+
+                if cols[pcol] == releasesuite:
+                    line = '# suite disabled by curtin: %s' % line
+            newsrc += line
+        retsrc = newsrc
+
+    return retsrc
+
+
+def generate_sources_list(cfg, release, mirrors, target=None):
+    """ generate_sources_list
+        create a source.list file based on a custom or default template
+        by replacing mirrors and release in the template
+    """
+    default_mirrors = get_default_mirrors(util.get_architecture(target))
+    aptsrc = "/etc/apt/sources.list"
+    params = {'RELEASE': release}
+    for k in mirrors:
+        params[k] = mirrors[k]
+
+    tmpl = cfg.get('sources_list', None)
+    if tmpl is None:
+        LOG.info("No custom template provided, fall back to modify"
+                 "mirrors in %s on the target system", aptsrc)
+        tmpl = util.load_file(util.target_path(target, aptsrc))
+        # Strategy if no custom template was provided:
+        # - Only replacing mirrors
+        # - no reason to replace "release" as it is from target anyway
+        # - The less we depend upon, the more stable this is against changes
+        # - warn if expected original content wasn't found
+        tmpl = mirror_to_placeholder(tmpl, default_mirrors['PRIMARY'],
+                                     "$MIRROR")
+        tmpl = mirror_to_placeholder(tmpl, default_mirrors['SECURITY'],
+                                     "$SECURITY")
+
+    orig = util.target_path(target, aptsrc)
+    if os.path.exists(orig):
+        os.rename(orig, orig + ".curtin.old")
+
+    rendered = util.render_string(tmpl, params)
+    disabled = disable_suites(cfg.get('disable_suites'), rendered, release)
+    util.write_file(util.target_path(target, aptsrc), disabled, mode=0o644)
+
+    # protect the just generated sources.list from cloud-init
+    cloudfile = "/etc/cloud/cloud.cfg.d/curtin-preserve-sources.cfg"
+    # this has to work with older cloud-init as well, so use old key
+    cloudconf = yaml.dump({'apt_preserve_sources_list': True}, indent=1)
+    try:
+        util.write_file(util.target_path(target, cloudfile),
+                        cloudconf, mode=0o644)
+    except IOError:
+        LOG.exception("Failed to protect source.list from cloud-init in (%s)",
+                      util.target_path(target, cloudfile))
+        raise
+
+
+def add_apt_key_raw(key, target=None):
+    """
+    actual adding of a key as defined in key argument
+    to the system
+    """
+    LOG.debug("Adding key:\n'%s'", key)
+    try:
+        util.subp(['apt-key', 'add', '-'], data=key.encode(), target=target)
+    except util.ProcessExecutionError:
+        LOG.exception("failed to add apt GPG Key to apt keyring")
+        raise
+
+
+def add_apt_key(ent, target=None):
+    """
+    Add key to the system as defined in ent (if any).
+    Supports raw keys or keyid's
+    The latter will as a first step fetched to get the raw key
+    """
+    if 'keyid' in ent and 'key' not in ent:
+        keyserver = DEFAULT_KEYSERVER
+        if 'keyserver' in ent:
+            keyserver = ent['keyserver']
+
+        ent['key'] = gpg.getkeybyid(ent['keyid'], keyserver)
+
+    if 'key' in ent:
+        add_apt_key_raw(ent['key'], target)
+
+
+def add_apt_sources(srcdict, target=None, template_params=None,
+                    aa_repo_match=None):
+    """
+    add entries in /etc/apt/sources.list.d for each abbreviated
+    sources.list entry in 'srcdict'.  When rendering template, also
+    include the values in dictionary searchList
+    """
+    if template_params is None:
+        template_params = {}
+
+    if aa_repo_match is None:
+        raise ValueError('did not get a valid repo matcher')
+
+    if not isinstance(srcdict, dict):
+        raise TypeError('unknown apt format: %s' % (srcdict))
+
+    for filename in srcdict:
+        ent = srcdict[filename]
+        if 'filename' not in ent:
+            ent['filename'] = filename
+
+        add_apt_key(ent, target)
+
+        if 'source' not in ent:
+            continue
+        source = ent['source']
+        source = util.render_string(source, template_params)
+
+        if not ent['filename'].startswith("/"):
+            ent['filename'] = os.path.join("/etc/apt/sources.list.d/",
+                                           ent['filename'])
+        if not ent['filename'].endswith(".list"):
+            ent['filename'] += ".list"
+
+        if aa_repo_match(source):
+            try:
+                with util.ChrootableTarget(
+                        target, sys_resolvconf=True) as in_chroot:
+                    in_chroot.subp(["add-apt-repository", source])
+            except util.ProcessExecutionError:
+                LOG.exception("add-apt-repository failed.")
+                raise
+            continue
+
+        sourcefn = util.target_path(target, ent['filename'])
+        try:
+            contents = "%s\n" % (source)
+            util.write_file(sourcefn, contents, omode="a")
+        except IOError as detail:
+            LOG.exception("failed write to file %s: %s", sourcefn, detail)
+            raise
+
+    util.apt_update(target=target, force=True,
+                    comment="apt-source changed config")
+
+    return
+
+
+def search_for_mirror(candidates):
+    """
+    Search through a list of mirror urls for one that works
+    This needs to return quickly.
+    """
+    if candidates is None:
+        return None
+
+    LOG.debug("search for mirror in candidates: '%s'", candidates)
+    for cand in candidates:
+        try:
+            if util.is_resolvable_url(cand):
+                LOG.debug("found working mirror: '%s'", cand)
+                return cand
+        except Exception:
+            pass
+    return None
+
+
+def update_mirror_info(pmirror, smirror, arch):
+    """sets security mirror to primary if not defined.
+       returns defaults if no mirrors are defined"""
+    if pmirror is not None:
+        if smirror is None:
+            smirror = pmirror
+        return {'PRIMARY': pmirror,
+                'SECURITY': smirror}
+    return get_default_mirrors(arch)
+
+
+def get_arch_mirrorconfig(cfg, mirrortype, arch):
+    """out of a list of potential mirror configurations select
+       and return the one matching the architecture (or default)"""
+    # select the mirror specification (if-any)
+    mirror_cfg_list = cfg.get(mirrortype, None)
+    if mirror_cfg_list is None:
+        return None
+
+    # select the specification matching the target arch
+    default = None
+    for mirror_cfg_elem in mirror_cfg_list:
+        arches = mirror_cfg_elem.get("arches")
+        if arch in arches:
+            return mirror_cfg_elem
+        if "default" in arches:
+            default = mirror_cfg_elem
+    return default
+
+
+def get_mirror(cfg, mirrortype, arch):
+    """pass the three potential stages of mirror specification
+       returns None is neither of them found anything otherwise the first
+       hit is returned"""
+    mcfg = get_arch_mirrorconfig(cfg, mirrortype, arch)
+    if mcfg is None:
+        return None
+
+    # directly specified
+    mirror = mcfg.get("uri", None)
+
+    # fallback to search if specified
+    if mirror is None:
+        # list of mirrors to try to resolve
+        mirror = search_for_mirror(mcfg.get("search", None))
+
+    return mirror
+
+
+def find_apt_mirror_info(cfg, arch=None):
+    """find_apt_mirror_info
+       find an apt_mirror given the cfg provided.
+       It can check for separate config of primary and security mirrors
+       If only primary is given security is assumed to be equal to primary
+       If the generic apt_mirror is given that is defining for both
+    """
+
+    if arch is None:
+        arch = util.get_architecture()
+        LOG.debug("got arch for mirror selection: %s", arch)
+    pmirror = get_mirror(cfg, "primary", arch)
+    LOG.debug("got primary mirror: %s", pmirror)
+    smirror = get_mirror(cfg, "security", arch)
+    LOG.debug("got security mirror: %s", smirror)
+
+    # Note: curtin has no cloud-datasource fallback
+
+    mirror_info = update_mirror_info(pmirror, smirror, arch)
+
+    # less complex replacements use only MIRROR, derive from primary
+    mirror_info["MIRROR"] = mirror_info["PRIMARY"]
+
+    return mirror_info
+
+
+def apply_apt_proxy_config(cfg, proxy_fname, config_fname):
+    """apply_apt_proxy_config
+       Applies any apt*proxy config from if specified
+    """
+    # Set up any apt proxy
+    cfgs = (('proxy', 'Acquire::http::Proxy "%s";'),
+            ('http_proxy', 'Acquire::http::Proxy "%s";'),
+            ('ftp_proxy', 'Acquire::ftp::Proxy "%s";'),
+            ('https_proxy', 'Acquire::https::Proxy "%s";'))
+
+    proxies = [fmt % cfg.get(name) for (name, fmt) in cfgs if cfg.get(name)]
+    if len(proxies):
+        LOG.debug("write apt proxy info to %s", proxy_fname)
+        util.write_file(proxy_fname, '\n'.join(proxies) + '\n')
+    elif os.path.isfile(proxy_fname):
+        util.del_file(proxy_fname)
+        LOG.debug("no apt proxy configured, removed %s", proxy_fname)
+
+    if cfg.get('conf', None):
+        LOG.debug("write apt config info to %s", config_fname)
+        util.write_file(config_fname, cfg.get('conf'))
+    elif os.path.isfile(config_fname):
+        util.del_file(config_fname)
+        LOG.debug("no apt config configured, removed %s", config_fname)
+
+
+def apt_command(args):
+    """ Main entry point for curtin apt-config standalone command
+        This does not read the global config as handled by curthooks, but
+        instead one can specify a different "target" and a new cfg via --config
+        """
+    cfg = config.load_command_config(args, {})
+
+    if args.target is not None:
+        target = args.target
+    else:
+        state = util.load_command_environment()
+        target = state['target']
+
+    if target is None:
+        sys.stderr.write("Unable to find target.  "
+                         "Use --target or set TARGET_MOUNT_POINT\n")
+        sys.exit(2)
+
+    apt_cfg = cfg.get("apt")
+    # if no apt config section is available, do nothing
+    if apt_cfg is not None:
+        LOG.debug("Handling apt to target %s with config %s",
+                  target, apt_cfg)
+        try:
+            with util.ChrootableTarget(target, sys_resolvconf=True):
+                handle_apt(apt_cfg, target)
+        except (RuntimeError, TypeError, ValueError, IOError):
+            LOG.exception("Failed to configure apt features '%s'", apt_cfg)
+            sys.exit(1)
+    else:
+        LOG.info("No apt config provided, skipping")
+
+    sys.exit(0)
+
+
+def translate_old_apt_features(cfg):
+    """translate the few old apt related features into the new config format"""
+    predef_apt_cfg = cfg.get("apt")
+    if predef_apt_cfg is None:
+        cfg['apt'] = {}
+        predef_apt_cfg = cfg.get("apt")
+
+    if cfg.get('apt_proxy') is not None:
+        if predef_apt_cfg.get('proxy') is not None:
+            msg = ("Error in apt_proxy configuration: "
+                   "old and new format of apt features "
+                   "are mutually exclusive")
+            LOG.error(msg)
+            raise ValueError(msg)
+
+        cfg['apt']['proxy'] = cfg.get('apt_proxy')
+        LOG.debug("Transferred %s into new format: %s", cfg.get('apt_proxy'),
+                  cfg.get('apte'))
+        del cfg['apt_proxy']
+
+    if cfg.get('apt_mirrors') is not None:
+        if predef_apt_cfg.get('mirrors') is not None:
+            msg = ("Error in apt_mirror configuration: "
+                   "old and new format of apt features "
+                   "are mutually exclusive")
+            LOG.error(msg)
+            raise ValueError(msg)
+
+        old = cfg.get('apt_mirrors')
+        cfg['apt']['primary'] = [{"arches": ["default"],
+                                  "uri": old.get('ubuntu_archive')}]
+        cfg['apt']['security'] = [{"arches": ["default"],
+                                   "uri": old.get('ubuntu_security')}]
+        LOG.debug("Transferred %s into new format: %s", cfg.get('apt_mirror'),
+                  cfg.get('apt'))
+        del cfg['apt_mirrors']
+        # to work this also needs to disable the default protection
+        psl = predef_apt_cfg.get('preserve_sources_list')
+        if psl is not None:
+            if config.value_as_boolean(psl) is True:
+                msg = ("Error in apt_mirror configuration: "
+                       "apt_mirrors and preserve_sources_list: True "
+                       "are mutually exclusive")
+                LOG.error(msg)
+                raise ValueError(msg)
+        cfg['apt']['preserve_sources_list'] = False
+
+    if cfg.get('debconf_selections') is not None:
+        if predef_apt_cfg.get('debconf_selections') is not None:
+            msg = ("Error in debconf_selections configuration: "
+                   "old and new format of apt features "
+                   "are mutually exclusive")
+            LOG.error(msg)
+            raise ValueError(msg)
+
+        selsets = cfg.get('debconf_selections')
+        cfg['apt']['debconf_selections'] = selsets
+        LOG.info("Transferred %s into new format: %s",
+                 cfg.get('debconf_selections'),
+                 cfg.get('apt'))
+        del cfg['debconf_selections']
+
+    return cfg
+
+
+CMD_ARGUMENTS = (
+    ((('-c', '--config'),
+      {'help': 'read configuration from cfg', 'action': util.MergedCmdAppend,
+       'metavar': 'FILE', 'type': argparse.FileType("rb"),
+       'dest': 'cfgopts', 'default': []}),
+     (('-t', '--target'),
+      {'help': 'chroot to target. default is env[TARGET_MOUNT_POINT]',
+       'action': 'store', 'metavar': 'TARGET',
+       'default': os.environ.get('TARGET_MOUNT_POINT')}),)
+)
+
+
+def POPULATE_SUBCMD(parser):
+    """Populate subcommand option parsing for apt-config"""
+    populate_one_subcmd(parser, CMD_ARGUMENTS, apt_command)
+
+CONFIG_CLEANERS = {
+    'cloud-init': clean_cloud_init,
+}
+
+# vi: ts=4 expandtab syntax=python
 
=== added file 'curtin/commands/block_info.py'
--- curtin/commands/block_info.py	1970-01-01 00:00:00 +0000
+++ curtin/commands/block_info.py	2016-10-03 18:55:20 +0000
@@ -0,0 +1,75 @@
+#   Copyright (C) 2016 Canonical Ltd.
+#
+#   Author: Wesley Wiedenmeier <[e-mail]>
+#
+#   Curtin is free software: you can redistribute it and/or modify it under
+#   the terms of the GNU Affero General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   Curtin is distributed in the hope that it will be useful, but WITHOUT ANY
+#   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#   FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+#   more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with Curtin.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+from . import populate_one_subcmd
+from curtin import (block, util)
+
+
+def block_info_main(args):
+    """get information about block devices, similar to lsblk"""
+    if not args.devices:
+        raise ValueError('devices to scan must be specified')
+    if not all(block.is_block_device(d) for d in args.devices):
+        raise ValueError('invalid device(s)')
+
+    def add_size_to_holders_tree(tree):
+        """add size information to generated holders trees"""
+        size_file = os.path.join(tree['device'], 'size')
+        # size file is always represented in 512 byte sectors even if
+        # underlying disk uses a larger logical_block_size
+        size = ((512 * int(util.load_file(size_file)))
+                if os.path.exists(size_file) else None)
+        tree['size'] = util.bytes2human(size) if args.human else str(size)
+        for holder in tree['holders']:
+            add_size_to_holders_tree(holder)
+        return tree
+
+    def format_name(tree):
+        """format information for human readable display"""
+        res = {
+            'name': ' - '.join((tree['name'], tree['dev_type'], tree['size'])),
+            'holders': []
+        }
+        for holder in tree['holders']:
+            res['holders'].append(format_name(holder))
+        return res
+
+    trees = [add_size_to_holders_tree(t) for t in
+             [block.clear_holders.gen_holders_tree(d) for d in args.devices]]
+
+    print(util.json_dumps(trees) if args.json else
+          '\n'.join(block.clear_holders.format_holders_tree(t) for t in
+                    [format_name(tree) for tree in trees]))
+
+    return 0
+
+
+CMD_ARGUMENTS = (
+    ('devices',
+     {'help': 'devices to get info for', 'default': [], 'nargs': '+'}),
+    ('--human',
+     {'help': 'output size in human readable format', 'default': False,
+      'action': 'store_true'}),
+    (('-j', '--json'),
+     {'help': 'output data in json format', 'default': False,
+      'action': 'store_true'}),
+)
+
+
+def POPULATE_SUBCMD(parser):
+    populate_one_subcmd(parser, CMD_ARGUMENTS, block_info_main)
 
=== modified file 'curtin/commands/block_meta.py'
--- curtin/commands/block_meta.py	2016-10-03 18:00:41 +0000
+++ curtin/commands/block_meta.py	2016-10-03 18:55:20 +0000
@@ -17,9 +17,8 @@
 
 from collections import OrderedDict
 from curtin import (block, config, util)
-from curtin.block import mdadm
+from curtin.block import (mdadm, mkfs, clear_holders, lvm)
 from curtin.log import LOG
-from curtin.block import mkfs
 from curtin.reporter import events
 
 from . import populate_one_subcmd
@@ -28,7 +27,7 @@
 import glob
 import os
 import platform
-import re
+import string
 import sys
 import tempfile
 import time
@@ -129,128 +128,6 @@
     return "mbr"
 
 
-def block_find_sysfs_path(devname):
-    # return the path in sys for device named devname
-    # support either short name ('sda') or full path /dev/sda
-    #  sda -> /sys/class/block/sda
-    #  sda1 -> /sys/class/block/sda/sda1
-    if not devname:
-        raise ValueError("empty devname provided to find_sysfs_path")
-
-    sys_class_block = '/sys/class/block/'
-    basename = os.path.basename(devname)
-    # try without parent blockdevice, then prepend parent
-    paths = [
-        os.path.join(sys_class_block, basename),
-        os.path.join(sys_class_block,
-                     re.split('[\d+]', basename)[0], basename),
-    ]
-
-    # find path to devname directory in sysfs
-    devname_sysfs = None
-    for path in paths:
-        if os.path.exists(path):
-            devname_sysfs = path
-
-    if devname_sysfs is None:
-        err = ('No sysfs path to device:'
-               ' {}'.format(devname_sysfs))
-        LOG.error(err)
-        raise ValueError(err)
-
-    return devname_sysfs
-
-
-def get_holders(devname):
-    # Look up any block device holders.
-    # Handle devices and partitions as devnames (vdb, md0, vdb7)
-    devname_sysfs = block_find_sysfs_path(devname)
-    if devname_sysfs:
-        holders = os.listdir(os.path.join(devname_sysfs, 'holders'))
-        LOG.debug("devname '%s' had holders: %s", devname, ','.join(holders))
-        return holders
-
-    LOG.debug('get_holders: did not find sysfs path for %s', devname)
-    return []
-
-
-def clear_holders(sys_block_path):
-    holders = os.listdir(os.path.join(sys_block_path, "holders"))
-    LOG.info("clear_holders running on '%s', with holders '%s'" %
-             (sys_block_path, holders))
-    for holder in holders:
-        # get path to holder in /sys/block, then clear it
-        try:
-            holder_realpath = os.path.realpath(
-                os.path.join(sys_block_path, "holders", holder))
-            clear_holders(holder_realpath)
-        except IOError as e:
-            # something might have already caused the holder to go away
-            if util.is_file_not_found_exc(e):
-                pass
-            pass
-
-    # detect what type of holder is using this volume and shut it down, need to
-    # find more robust name of doing detection
-    if "bcache" in sys_block_path:
-        # bcache device
-        part_devs = []
-        for part_dev in glob.glob(os.path.join(sys_block_path,
-                                               "slaves", "*", "dev")):
-            with open(part_dev, "r") as fp:
-                part_dev_id = fp.read().rstrip()
-                part_devs.append(
-                    os.path.split(os.path.realpath(os.path.join("/dev/block",
-                                  part_dev_id)))[-1])
-        for cache_dev in glob.glob("/sys/fs/bcache/*/bdev*"):
-            for part_dev in part_devs:
-                if part_dev in os.path.realpath(cache_dev):
-                    # This is our bcache device, stop it, wait for udev to
-                    # settle
-                    with open(os.path.join(os.path.split(cache_dev)[0],
-                              "stop"), "w") as fp:
-                        LOG.info("stopping: %s" % fp)
-                        fp.write("1")
-                        udevadm_settle()
-                    break
-        for part_dev in part_devs:
-            block.wipe_volume(os.path.join("/dev", part_dev),
-                              mode="superblock")
-
-    if os.path.exists(os.path.join(sys_block_path, "bcache")):
-        # bcache device that isn't running, if it were, we would have found it
-        # when we looked for holders
-        try:
-            with open(os.path.join(sys_block_path, "bcache", "set", "stop"),
-                      "w") as fp:
-                LOG.info("stopping: %s" % fp)
-                fp.write("1")
-        except IOError as e:
-            if not util.is_file_not_found_exc(e):
-                raise e
-            with open(os.path.join(sys_block_path, "bcache", "stop"),
-                      "w") as fp:
-                LOG.info("stopping: %s" % fp)
-                fp.write("1")
-        udevadm_settle()
-
-    if os.path.exists(os.path.join(sys_block_path, "md")):
-        # md device
-        block_dev = os.path.join("/dev/", os.path.split(sys_block_path)[-1])
-        # if these fail its okay, the array might not be assembled and thats
-        # fine
-        mdadm.mdadm_stop(block_dev)
-        mdadm.mdadm_remove(block_dev)
-
-    elif os.path.exists(os.path.join(sys_block_path, "dm")):
-        # Shut down any volgroups
-        with open(os.path.join(sys_block_path, "dm", "name"), "r") as fp:
-            name = fp.read().split('-')
-        util.subp(["lvremove", "--force", name[0].rstrip(), name[1].rstrip()],
-                  rcs=[0, 5])
-        util.subp(["vgremove", name[0].rstrip()], rcs=[0, 5, 6])
-
-
 def devsync(devpath):
     LOG.debug('devsync for %s', devpath)
     util.subp(['partprobe', devpath], rcs=[0, 1])
@@ -265,14 +142,6 @@
     raise OSError('Failed to find device at path: %s', devpath)
 
 
-def determine_partition_kname(disk_kname, partition_number):
-    for dev_type in ["nvme", "mmcblk"]:
-        if disk_kname.startswith(dev_type):
-            partition_number = "p%s" % partition_number
-            break
-    return "%s%s" % (disk_kname, partition_number)
-
-
 def determine_partition_number(partition_id, storage_config):
     vol = storage_config.get(partition_id)
     partnumber = vol.get('number')
@@ -304,6 +173,18 @@
     return partnumber
 
 
+def sanitize_dname(dname):
+    """
+    dnames should be sanitized before writing rule files, in case maas has
+    emitted a dname with a special character
+
+    only letters, numbers and '-' and '_' are permitted, as this will be
+    used for a device path. spaces are also not permitted
+    """
+    valid = string.digits + string.ascii_letters + '-_'
+    return ''.join(c if c in valid else '-' for c in dname)
+
+
 def make_dname(volume, storage_config):
     state = util.load_command_environment()
     rules_dir = os.path.join(state['scratch'], "rules.d")
@@ -321,7 +202,7 @@
     # we may not always be able to find a uniq identifier on devices with names
     if not ptuuid and vol.get('type') in ["disk", "partition"]:
         LOG.warning("Can't find a uuid for volume: {}. Skipping dname.".format(
-            dname))
+            volume))
         return
 
     rule = [
@@ -346,11 +227,24 @@
         volgroup_name = storage_config.get(vol.get('volgroup')).get('name')
         dname = "%s-%s" % (volgroup_name, dname)
         rule.append(compose_udev_equality("ENV{DM_NAME}", dname))
-    rule.append("SYMLINK+=\"disk/by-dname/%s\"" % dname)
+    else:
+        raise ValueError('cannot make dname for device with type: {}'
+                         .format(vol.get('type')))
+
+    # note: this sanitization is done here instead of for all name attributes
+    #       at the beginning of storage configuration, as some devices, such as
+    #       lvm devices may use the name attribute and may permit special chars
+    sanitized = sanitize_dname(dname)
+    if sanitized != dname:
+        LOG.warning(
+            "dname modified to remove invalid chars. old: '{}' new: '{}'"
+            .format(dname, sanitized))
+
+    rule.append("SYMLINK+=\"disk/by-dname/%s\"" % sanitized)
     LOG.debug("Writing dname udev rule '{}'".format(str(rule)))
     util.ensure_dir(rules_dir)
-    with open(os.path.join(rules_dir, volume), "w") as fp:
-        fp.write(', '.join(rule))
+    rule_file = os.path.join(rules_dir, '{}.rules'.format(sanitized))
+    util.write_file(rule_file, ', '.join(rule))
 
 
 def get_path_to_storage_volume(volume, storage_config):
@@ -368,9 +262,9 @@
         partnumber = determine_partition_number(vol.get('id'), storage_config)
         disk_block_path = get_path_to_storage_volume(vol.get('device'),
                                                      storage_config)
-        (base_path, disk_kname) = os.path.split(disk_block_path)
-        partition_kname = determine_partition_kname(disk_kname, partnumber)
-        volume_path = os.path.join(base_path, partition_kname)
+        disk_kname = block.path_to_kname(disk_block_path)
+        partition_kname = block.partition_kname(disk_kname, partnumber)
+        volume_path = block.kname_to_path(partition_kname)
         devsync_vol = os.path.join(disk_block_path)
 
     elif vol.get('type') == "disk":
@@ -419,13 +313,15 @@
         # block devs are in the slaves dir there. Then, those blockdevs can be
         # checked against the kname of the devs in the config for the desired
         # bcache device. This is not very elegant though
-        backing_device_kname = os.path.split(get_path_to_storage_volume(
-            vol.get('backing_device'), storage_config))[-1]
+        backing_device_path = get_path_to_storage_volume(
+            vol.get('backing_device'), storage_config)
+        backing_device_kname = block.path_to_kname(backing_device_path)
         sys_path = list(filter(lambda x: backing_device_kname in x,
                                glob.glob("/sys/block/bcache*/slaves/*")))[0]
         while "bcache" not in os.path.split(sys_path)[-1]:
             sys_path = os.path.split(sys_path)[0]
-        volume_path = os.path.join("/dev", os.path.split(sys_path)[-1])
+        bcache_kname = block.path_to_kname(sys_path)
+        volume_path = block.kname_to_path(bcache_kname)
         LOG.debug('got bcache volume path {}'.format(volume_path))
 
     else:
@@ -442,62 +338,35 @@
 
 
 def disk_handler(info, storage_config):
+    _dos_names = ['dos', 'msdos']
     ptable = info.get('ptable')
-
     disk = get_path_to_storage_volume(info.get('id'), storage_config)
 
-    # Handle preserve flag
-    if info.get('preserve'):
-        if not ptable:
-            # Don't need to check state, return
-            return
-
-        # Check state of current ptable
-        try:
-            (out, _err) = util.subp(["blkid", "-o", "export", disk],
-                                    capture=True)
-        except util.ProcessExecutionError:
-            raise ValueError("disk '%s' has no readable partition table or \
-                cannot be accessed, but preserve is set to true, so cannot \
-                continue")
-        current_ptable = list(filter(lambda x: "PTTYPE" in x,
-                                     out.splitlines()))[0].split("=")[-1]
-        if current_ptable == "dos" and ptable != "msdos" or \
-                current_ptable == "gpt" and ptable != "gpt":
-            raise ValueError("disk '%s' does not have correct \
-                partition table, but preserve is set to true, so not \
-                creating table, so not creating table." % info.get('id'))
-        LOG.info("disk '%s' marked to be preserved, so keeping partition \
-                 table")
-        return
-
-    # Wipe the disk
-    if info.get('wipe') and info.get('wipe') != "none":
-        # The disk has a lable, clear all partitions
-        mdadm.mdadm_assemble(scan=True)
-        disk_kname = os.path.split(disk)[-1]
-        syspath_partitions = list(
-            os.path.split(prt)[0] for prt in
-            glob.glob("/sys/block/%s/*/partition" % disk_kname))
-        for partition in syspath_partitions:
-            clear_holders(partition)
-            with open(os.path.join(partition, "dev"), "r") as fp:
-                block_no = fp.read().rstrip()
-            partition_path = os.path.realpath(
-                os.path.join("/dev/block", block_no))
-            block.wipe_volume(partition_path, mode=info.get('wipe'))
-
-        clear_holders("/sys/block/%s" % disk_kname)
-        block.wipe_volume(disk, mode=info.get('wipe'))
-
-    # Create partition table on disk
-    if info.get('ptable'):
-        LOG.info("labeling device: '%s' with '%s' partition table", disk,
-                 ptable)
-        if ptable == "gpt":
-            util.subp(["sgdisk", "--clear", disk])
-        elif ptable == "msdos":
-            util.subp(["parted", disk, "--script", "mklabel", "msdos"])
+    if config.value_as_boolean(info.get('preserve')):
+        # Handle preserve flag, verifying if ptable specified in config
+        if config.value_as_boolean(ptable):
+            current_ptable = block.get_part_table_type(disk)
+            if not ((ptable in _dos_names and current_ptable in _dos_names) or
+                    (ptable == 'gpt' and current_ptable == 'gpt')):
+                raise ValueError(
+                    "disk '%s' does not have correct partition table or "
+                    "cannot be read, but preserve is set to true. "
+                    "cannot continue installation." % info.get('id'))
+        LOG.info("disk '%s' marked to be preserved, so keeping partition "
+                 "table" % disk)
+    else:
+        # wipe the disk and create the partition table if instructed to do so
+        if config.value_as_boolean(info.get('wipe')):
+            block.wipe_volume(disk, mode=info.get('wipe'))
+        if config.value_as_boolean(ptable):
+            LOG.info("labeling device: '%s' with '%s' partition table", disk,
+                     ptable)
+            if ptable == "gpt":
+                util.subp(["sgdisk", "--clear", disk])
+            elif ptable in _dos_names:
+                util.subp(["parted", disk, "--script", "mklabel", "msdos"])
+            else:
+                raise ValueError('invalid partition table type: %s', ptable)
 
     # Make the name if needed
     if info.get('name'):
@@ -542,13 +411,12 @@
 
     disk = get_path_to_storage_volume(device, storage_config)
     partnumber = determine_partition_number(info.get('id'), storage_config)
-
-    disk_kname = os.path.split(
-        get_path_to_storage_volume(device, storage_config))[-1]
+    disk_kname = block.path_to_kname(disk)
+    disk_sysfs_path = block.sys_block_path(disk)
     # consider the disks logical sector size when calculating sectors
     try:
-        prefix = "/sys/block/%s/queue/" % disk_kname
-        with open(prefix + "logical_block_size", "r") as f:
+        lbs_path = os.path.join(disk_sysfs_path, 'queue', 'logical_block_size')
+        with open(lbs_path, 'r') as f:
             l = f.readline()
             logical_block_size_bytes = int(l)
     except:
@@ -566,17 +434,14 @@
                     extended_part_no = determine_partition_number(
                         key, storage_config)
                     break
-            partition_kname = determine_partition_kname(
-                disk_kname, extended_part_no)
-            previous_partition = "/sys/block/%s/%s/" % \
-                (disk_kname, partition_kname)
+            pnum = extended_part_no
         else:
             pnum = find_previous_partition(device, info['id'], storage_config)
-            LOG.debug("previous partition number for '%s' found to be '%s'",
-                      info.get('id'), pnum)
-            partition_kname = determine_partition_kname(disk_kname, pnum)
-            previous_partition = "/sys/block/%s/%s/" % \
-                (disk_kname, partition_kname)
+
+        LOG.debug("previous partition number for '%s' found to be '%s'",
+                  info.get('id'), pnum)
+        partition_kname = block.partition_kname(disk_kname, pnum)
+        previous_partition = os.path.join(disk_sysfs_path, partition_kname)
         LOG.debug("previous partition: {}".format(previous_partition))
         # XXX: sys/block/X/{size,start} is *ALWAYS* in 512b value
         previous_size = util.load_file(os.path.join(previous_partition,
@@ -629,9 +494,9 @@
         length_sectors = length_sectors + (logdisks * alignment_offset)
 
     # Handle preserve flag
-    if info.get('preserve'):
+    if config.value_as_boolean(info.get('preserve')):
         return
-    elif storage_config.get(device).get('preserve'):
+    elif config.value_as_boolean(storage_config.get(device).get('preserve')):
         raise NotImplementedError("Partition '%s' is not marked to be \
             preserved, but device '%s' is. At this time, preserving devices \
             but not also the partitions on the devices is not supported, \
@@ -674,11 +539,16 @@
     else:
         raise ValueError("parent partition has invalid partition table")
 
-    # Wipe the partition if told to do so
-    if info.get('wipe') and info.get('wipe') != "none":
-        block.wipe_volume(
-            get_path_to_storage_volume(info.get('id'), storage_config),
-            mode=info.get('wipe'))
+    # Wipe the partition if told to do so, do not wipe dos extended partitions
+    # as this may damage the extended partition table
+    if config.value_as_boolean(info.get('wipe')):
+        if info.get('flag') == "extended":
+            LOG.warn("extended partitions do not need wiping, so skipping: "
+                     "'%s'" % info.get('id'))
+        else:
+            block.wipe_volume(
+                get_path_to_storage_volume(info.get('id'), storage_config),
+                mode=info.get('wipe'))
     # Make the name if needed
     if storage_config.get(device).get('name') and partition_type != 'extended':
         make_dname(info.get('id'), storage_config)
@@ -694,7 +564,7 @@
     volume_path = get_path_to_storage_volume(volume, storage_config)
 
     # Handle preserve flag
-    if info.get('preserve'):
+    if config.value_as_boolean(info.get('preserve')):
         # Volume marked to be preserved, not formatting
         return
 
@@ -776,26 +646,21 @@
                             storage_config))
 
     # Handle preserve flag
-    if info.get('preserve'):
+    if config.value_as_boolean(info.get('preserve')):
         # LVM will probably be offline, so start it
         util.subp(["vgchange", "-a", "y"])
         # Verify that volgroup exists and contains all specified devices
-        current_paths = []
-        (out, _err) = util.subp(["pvdisplay", "-C", "--separator", "=", "-o",
-                                "vg_name,pv_name", "--noheadings"],
-                                capture=True)
-        for line in out.splitlines():
-            if name in line:
-                current_paths.append(line.split("=")[-1])
-        if set(current_paths) != set(device_paths):
-            raise ValueError("volgroup '%s' marked to be preserved, but does \
-                             not exist or does not contain the right physical \
-                             volumes" % info.get('id'))
+        if set(lvm.get_pvols_in_volgroup(name)) != set(device_paths):
+            raise ValueError("volgroup '%s' marked to be preserved, but does "
+                             "not exist or does not contain the right "
+                             "physical volumes" % info.get('id'))
     else:
         # Create vgrcreate command and run
-        cmd = ["vgcreate", name]
-        cmd.extend(device_paths)
-        util.subp(cmd)
+        # capture output to avoid printing it to log
+        util.subp(['vgcreate', name] + device_paths, capture=True)
+
+    # refresh lvmetad
+    lvm.lvm_scan()
 
 
 def lvm_partition_handler(info, storage_config):
@@ -805,28 +670,23 @@
         raise ValueError("lvm volgroup for lvm partition must be specified")
     if not name:
         raise ValueError("lvm partition name must be specified")
+    if info.get('ptable'):
+        raise ValueError("Partition tables on top of lvm logical volumes is "
+                         "not supported")
 
     # Handle preserve flag
-    if info.get('preserve'):
-        (out, _err) = util.subp(["lvdisplay", "-C", "--separator", "=", "-o",
-                                "lv_name,vg_name", "--noheadings"],
-                                capture=True)
-        found = False
-        for line in out.splitlines():
-            if name in line:
-                if volgroup == line.split("=")[-1]:
-                    found = True
-                    break
-        if not found:
-            raise ValueError("lvm partition '%s' marked to be preserved, but \
-                             does not exist or does not mach storage \
-                             configuration" % info.get('id'))
+    if config.value_as_boolean(info.get('preserve')):
+        if name not in lvm.get_lvols_in_volgroup(volgroup):
+            raise ValueError("lvm partition '%s' marked to be preserved, but "
+                             "does not exist or does not mach storage "
+                             "configuration" % info.get('id'))
     elif storage_config.get(info.get('volgroup')).get('preserve'):
-        raise NotImplementedError("Lvm Partition '%s' is not marked to be \
-            preserved, but volgroup '%s' is. At this time, preserving \
-            volgroups but not also the lvm partitions on the volgroup is \
-            not supported, because of the possibility of damaging lvm \
-            partitions intended to be preserved." % (info.get('id'), volgroup))
+        raise NotImplementedError(
+            "Lvm Partition '%s' is not marked to be preserved, but volgroup "
+            "'%s' is. At this time, preserving volgroups but not also the lvm "
+            "partitions on the volgroup is not supported, because of the "
+            "possibility of damaging lvm  partitions intended to be "
+            "preserved." % (info.get('id'), volgroup))
     else:
         cmd = ["lvcreate", volgroup, "-n", name]
         if info.get('size'):
@@ -836,9 +696,8 @@
 
         util.subp(cmd)
 
-    if info.get('ptable'):
-        raise ValueError("Partition tables on top of lvm logical volumes is \
-                         not supported")
+    # refresh lvmetad
+    lvm.lvm_scan()
 
     make_dname(info.get('id'), storage_config)
 
@@ -925,7 +784,7 @@
                   zip(spare_devices, spare_device_paths)))
 
     # Handle preserve flag
-    if info.get('preserve'):
+    if config.value_as_boolean(info.get('preserve')):
         # check if the array is already up, if not try to assemble
         if not mdadm.md_check(md_devname, raidlevel,
                               device_paths, spare_device_paths):
@@ -981,9 +840,6 @@
         raise ValueError("backing device and cache device for bcache"
                          " must be specified")
 
-    # The bcache module is not loaded when bcache is installed by apt-get, so
-    # we will load it now
-    util.subp(["modprobe", "bcache"])
     bcache_sysfs = "/sys/fs/bcache"
     udevadm_settle(exists=bcache_sysfs)
 
@@ -1003,7 +859,7 @@
                           bcache_device, expected)
                 return
             LOG.debug('bcache device path not found: %s', expected)
-            local_holders = get_holders(bcache_device)
+            local_holders = clear_holders.get_holders(bcache_device)
             LOG.debug('got initial holders being "%s"', local_holders)
             if len(local_holders) == 0:
                 raise ValueError("holders == 0 , expected non-zero")
@@ -1033,7 +889,7 @@
 
     if cache_device:
         # /sys/class/block/XXX/YYY/
-        cache_device_sysfs = block_find_sysfs_path(cache_device)
+        cache_device_sysfs = block.sys_block_path(cache_device)
 
         if os.path.exists(os.path.join(cache_device_sysfs, "bcache")):
             LOG.debug('caching device already exists at {}/bcache. Read '
@@ -1058,7 +914,7 @@
         ensure_bcache_is_registered(cache_device, target_sysfs_path)
 
     if backing_device:
-        backing_device_sysfs = block_find_sysfs_path(backing_device)
+        backing_device_sysfs = block.sys_block_path(backing_device)
         target_sysfs_path = os.path.join(backing_device_sysfs, "bcache")
         if not os.path.exists(os.path.join(backing_device_sysfs, "bcache")):
             util.subp(["make-bcache", "-B", backing_device])
@@ -1066,7 +922,7 @@
 
         # via the holders we can identify which bcache device we just created
         # for a given backing device
-        holders = get_holders(backing_device)
+        holders = clear_holders.get_holders(backing_device)
         if len(holders) != 1:
             err = ('Invalid number {} of holding devices:'
                    ' "{}"'.format(len(holders), holders))
@@ -1158,6 +1014,21 @@
     # set up reportstack
     stack_prefix = state.get('report_stack_prefix', '')
 
+    # shut down any already existing storage layers above any disks used in
+    # config that have 'wipe' set
+    with events.ReportEventStack(
+            name=stack_prefix, reporting_enabled=True, level='INFO',
+            description="removing previous storage devices"):
+        clear_holders.start_clear_holders_deps()
+        disk_paths = [get_path_to_storage_volume(k, storage_config_dict)
+                      for (k, v) in storage_config_dict.items()
+                      if v.get('type') == 'disk' and
+                      config.value_as_boolean(v.get('wipe')) and
+                      not config.value_as_boolean(v.get('preserve'))]
+        clear_holders.clear_holders(disk_paths)
+        # if anything was not properly shut down, stop installation
+        clear_holders.assert_clear(disk_paths)
+
     for item_id, command in storage_config_dict.items():
         handler = command_handlers.get(command['type'])
         if not handler:
 
=== modified file 'curtin/commands/block_wipe.py'
--- curtin/commands/block_wipe.py	2016-05-10 16:13:29 +0000
+++ curtin/commands/block_wipe.py	2016-10-03 18:55:20 +0000
@@ -21,7 +21,6 @@
 
 
 def wipe_main(args):
-    #  curtin clear-holders device [device2 [device3]]
     for blockdev in args.devices:
         try:
             block.wipe_volume(blockdev, mode=args.mode)
@@ -36,7 +35,7 @@
 CMD_ARGUMENTS = (
     ((('-m', '--mode'),
       {'help': 'mode for wipe.', 'action': 'store',
-       'default': 'superblocks',
+       'default': 'superblock',
        'choices': ['zero', 'superblock', 'superblock-recursive', 'random']}),
      ('devices',
       {'help': 'devices to wipe', 'default': [], 'nargs': '+'}),
 
=== added file 'curtin/commands/clear_holders.py'
--- curtin/commands/clear_holders.py	1970-01-01 00:00:00 +0000
+++ curtin/commands/clear_holders.py	2016-10-03 18:55:20 +0000
@@ -0,0 +1,48 @@
+#   Copyright (C) 2016 Canonical Ltd.
+#
+#   Author: Wesley Wiedenmeier <[e-mail]>
+#
+#   Curtin is free software: you can redistribute it and/or modify it under
+#   the terms of the GNU Affero General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   Curtin is distributed in the hope that it will be useful, but WITHOUT ANY
+#   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#   FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+#   more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with Curtin.  If not, see <http://www.gnu.org/licenses/>.
+
+from curtin import block
+from . import populate_one_subcmd
+
+
+def clear_holders_main(args):
+    """
+    wrapper for clear_holders accepting cli args
+    """
+    if (not all(block.is_block_device(device) for device in args.devices) or
+            len(args.devices) == 0):
+        raise ValueError('invalid devices specified')
+    block.clear_holders.start_clear_holders_deps()
+    block.clear_holders.clear_holders(args.devices, try_preserve=args.preserve)
+    if args.try_preserve:
+        print('ran clear_holders attempting to preserve data. however, '
+              'hotplug support for some devices may cause holders to restart ')
+    block.clear_holders.assert_clear(args.devices)
+
+
+CMD_ARGUMENTS = (
+    (('devices',
+      {'help': 'devices to free', 'default': [], 'nargs': '+'}),
+     (('-p', '--preserve'),
+      {'help': 'try to shut down holders without erasing anything',
+       'default': False, 'action': 'store_true'}),
+     )
+)
+
+
+def POPULATE_SUBCMD(parser):
+    populate_one_subcmd(parser, CMD_ARGUMENTS, clear_holders_main)
 
=== modified file 'curtin/commands/curthooks.py'
--- curtin/commands/curthooks.py	2016-10-03 18:00:41 +0000
+++ curtin/commands/curthooks.py	2016-10-03 18:55:20 +0000
@@ -16,10 +16,8 @@
 #   along with Curtin.  If not, see <http://www.gnu.org/licenses/>.
 
 import copy
-import glob
 import os
 import platform
-import re
 import sys
 import shutil
 import textwrap
@@ -30,8 +28,8 @@
 from curtin.log import LOG
 from curtin import swap
 from curtin import util
-from curtin import net
 from curtin.reporter import events
+from curtin.commands import apply_net, apt_config
 
 from . import populate_one_subcmd
 
@@ -90,45 +88,15 @@
                                          info.get('perms', "0644")))
 
 
-def apt_config(cfg, target):
-    # cfg['apt_proxy']
-
-    proxy_cfg_path = os.path.sep.join(
-        [target, '/etc/apt/apt.conf.d/90curtin-aptproxy'])
-    if cfg.get('apt_proxy'):
-        util.write_file(
-            proxy_cfg_path,
-            content='Acquire::HTTP::Proxy "%s";\n' % cfg['apt_proxy'])
+def do_apt_config(cfg, target):
+    cfg = apt_config.translate_old_apt_features(cfg)
+    apt_cfg = cfg.get("apt")
+    if apt_cfg is not None:
+        LOG.info("curthooks handling apt to target %s with config %s",
+                 target, apt_cfg)
+        apt_config.handle_apt(apt_cfg, target)
     else:
-        if os.path.isfile(proxy_cfg_path):
-            os.unlink(proxy_cfg_path)
-
-    # cfg['apt_mirrors']
-    # apt_mirrors:
-    #  ubuntu_archive: http://local.archive/ubuntu
-    #  ubuntu_security: http://local.archive/ubuntu
-    sources_list = os.path.sep.join([target, '/etc/apt/sources.list'])
-    if (isinstance(cfg.get('apt_mirrors'), dict) and
-            os.path.isfile(sources_list)):
-        repls = [
-            ('ubuntu_archive', r'http://\S*[.]*archive.ubuntu.com/\S*'),
-            ('ubuntu_security', r'http://security.ubuntu.com/\S*'),
-        ]
-        content = None
-        for name, regex in repls:
-            mirror = cfg['apt_mirrors'].get(name)
-            if not mirror:
-                continue
-
-            if content is None:
-                with open(sources_list) as fp:
-                    content = fp.read()
-                util.write_file(sources_list + ".dist", content)
-
-            content = re.sub(regex, mirror + " ", content)
-
-        if content is not None:
-            util.write_file(sources_list, content)
+        LOG.info("No apt config provided, skipping")
 
 
 def disable_overlayroot(cfg, target):
@@ -140,51 +108,6 @@
         shutil.move(local_conf, local_conf + ".old")
 
 
-def clean_cloud_init(target):
-    flist = glob.glob(
-        os.path.sep.join([target, "/etc/cloud/cloud.cfg.d/*dpkg*"]))
-
-    LOG.debug("cleaning cloud-init config from: %s" % flist)
-    for dpkg_cfg in flist:
-        os.unlink(dpkg_cfg)
-
-
-def _maybe_remove_legacy_eth0(target,
-                              path="/etc/network/interfaces.d/eth0.cfg"):
-    """Ubuntu cloud images previously included a 'eth0.cfg' that had
-       hard coded content.  That file would interfere with the rendered
-       configuration if it was present.
-
-       if the file does not exist do nothing.
-       If the file exists:
-         - with known content, remove it and warn
-         - with unknown content, leave it and warn
-    """
-
-    cfg = os.path.sep.join([target, path])
-    if not os.path.exists(cfg):
-        LOG.warn('Failed to find legacy conf file %s', cfg)
-        return
-
-    bmsg = "Dynamic networking config may not apply."
-    try:
-        contents = util.load_file(cfg)
-        known_contents = ["auto eth0", "iface eth0 inet dhcp"]
-        lines = [f.strip() for f in contents.splitlines()
-                 if not f.startswith("#")]
-        if lines == known_contents:
-            util.del_file(cfg)
-            msg = "removed %s with known contents" % cfg
-        else:
-            msg = (bmsg + " '%s' exists with user configured content." % cfg)
-    except:
-        msg = bmsg + " %s exists, but could not be read." % cfg
-        LOG.exception(msg)
-        return
-
-    LOG.warn(msg)
-
-
 def setup_zipl(cfg, target):
     if platform.machine() != 's390x':
         return
@@ -232,8 +155,8 @@
 def run_zipl(cfg, target):
     if platform.machine() != 's390x':
         return
-    with util.RunInChroot(target) as in_chroot:
-        in_chroot(['zipl'])
+    with util.ChrootableTarget(target) as in_chroot:
+        in_chroot.subp(['zipl'])
 
 
 def install_kernel(cfg, target):
@@ -250,126 +173,45 @@
     mapping = copy.deepcopy(KERNEL_MAPPING)
     config.merge_config(mapping, kernel_cfg.get('mapping', {}))
 
-    with util.RunInChroot(target) as in_chroot:
-
-        if kernel_package:
-            util.install_packages([kernel_package], target=target)
-            return
-
-        # uname[2] is kernel name (ie: 3.16.0-7-generic)
-        # version gets X.Y.Z, flavor gets anything after second '-'.
-        kernel = os.uname()[2]
-        codename, err = in_chroot(['lsb_release', '--codename', '--short'],
-                                  capture=True)
-        codename = codename.strip()
-        version, abi, flavor = kernel.split('-', 2)
-
-        try:
-            map_suffix = mapping[codename][version]
-        except KeyError:
-            LOG.warn("Couldn't detect kernel package to install for %s."
-                     % kernel)
-            if kernel_fallback is not None:
-                util.install_packages([kernel_fallback], target=target)
-            return
-
-        package = "linux-{flavor}{map_suffix}".format(
-            flavor=flavor, map_suffix=map_suffix)
-
-        if util.has_pkg_available(package, target):
-            if util.has_pkg_installed(package, target):
-                LOG.debug("Kernel package '%s' already installed", package)
-            else:
-                LOG.debug("installing kernel package '%s'", package)
-                util.install_packages([package], target=target)
-        else:
-            if kernel_fallback is not None:
-                LOG.info("Kernel package '%s' not available.  "
-                         "Installing fallback package '%s'.",
-                         package, kernel_fallback)
-                util.install_packages([kernel_fallback], target=target)
-            else:
-                LOG.warn("Kernel package '%s' not available and no fallback."
-                         " System may not boot.", package)
-
-
-def apply_debconf_selections(cfg, target):
-    # debconf_selections:
-    #  set1: |
-    #   cloud-init cloud-init/datasources multiselect MAAS
-    #  set2: pkg pkg/value string bar
-    selsets = cfg.get('debconf_selections')
-    if not selsets:
-        LOG.debug("debconf_selections was not set in config")
-        return
-
-    # for each entry in selections, chroot and apply them.
-    # keep a running total of packages we've seen.
-    pkgs_cfgd = set()
-    for key, content in selsets.items():
-        LOG.debug("setting for %s, %s" % (key, content))
-        util.subp(['chroot', target, 'debconf-set-selections'],
-                  data=content.encode())
-        for line in content.splitlines():
-            if line.startswith("#"):
-                continue
-            pkg = re.sub(r"[:\s].*", "", line)
-            pkgs_cfgd.add(pkg)
-
-    pkgs_installed = get_installed_packages(target)
-
-    LOG.debug("pkgs_cfgd: %s" % pkgs_cfgd)
-    LOG.debug("pkgs_installed: %s" % pkgs_installed)
-    need_reconfig = pkgs_cfgd.intersection(pkgs_installed)
-
-    if len(need_reconfig) == 0:
-        LOG.debug("no need for reconfig")
-        return
-
-    # For any packages that are already installed, but have preseed data
-    # we populate the debconf database, but the filesystem configuration
-    # would be preferred on a subsequent dpkg-reconfigure.
-    # so, what we have to do is "know" information about certain packages
-    # to unconfigure them.
-    unhandled = []
-    to_config = []
-    for pkg in need_reconfig:
-        if pkg in CONFIG_CLEANERS:
-            LOG.debug("unconfiguring %s" % pkg)
-            CONFIG_CLEANERS[pkg](target)
-            to_config.append(pkg)
-        else:
-            unhandled.append(pkg)
-
-    if len(unhandled):
-        LOG.warn("The following packages were installed and preseeded, "
-                 "but cannot be unconfigured: %s", unhandled)
-
-    util.subp(['chroot', target, 'dpkg-reconfigure',
-               '--frontend=noninteractive'] +
-              list(to_config), data=None)
-
-
-def get_installed_packages(target=None):
-    cmd = []
-    if target is not None:
-        cmd = ['chroot', target]
-    cmd.extend(['dpkg-query', '--list'])
-
-    (out, _err) = util.subp(cmd, capture=True)
-    if isinstance(out, bytes):
-        out = out.decode()
-
-    pkgs_inst = set()
-    for line in out.splitlines():
-        try:
-            (state, pkg, other) = line.split(None, 2)
-        except ValueError:
-            continue
-        if state.startswith("hi") or state.startswith("ii"):
-            pkgs_inst.add(re.sub(":.*", "", pkg))
-
-    return pkgs_inst
+    if kernel_package:
+        util.install_packages([kernel_package], target=target)
+        return
+
+    # uname[2] is kernel name (ie: 3.16.0-7-generic)
+    # version gets X.Y.Z, flavor gets anything after second '-'.
+    kernel = os.uname()[2]
+    codename, _ = util.subp(['lsb_release', '--codename', '--short'],
+                            capture=True, target=target)
+    codename = codename.strip()
+    version, abi, flavor = kernel.split('-', 2)
+
+    try:
+        map_suffix = mapping[codename][version]
+    except KeyError:
+        LOG.warn("Couldn't detect kernel package to install for %s."
+                 % kernel)
+        if kernel_fallback is not None:
+            util.install_packages([kernel_fallback], target=target)
+        return
+
+    package = "linux-{flavor}{map_suffix}".format(
+        flavor=flavor, map_suffix=map_suffix)
+
+    if util.has_pkg_available(package, target):
+        if util.has_pkg_installed(package, target):
+            LOG.debug("Kernel package '%s' already installed", package)
+        else:
+            LOG.debug("installing kernel package '%s'", package)
+            util.install_packages([package], target=target)
+    else:
+        if kernel_fallback is not None:
+            LOG.info("Kernel package '%s' not available.  "
+                     "Installing fallback package '%s'.",
+                     package, kernel_fallback)
+            util.install_packages([kernel_fallback], target=target)
+        else:
+            LOG.warn("Kernel package '%s' not available and no fallback."
+                     " System may not boot.", package)
 
 
 def setup_grub(cfg, target):
@@ -498,12 +340,11 @@
         util.subp(args + instdevs, env=env)
 
 
-def update_initramfs(target, all_kernels=False):
+def update_initramfs(target=None, all_kernels=False):
     cmd = ['update-initramfs', '-u']
     if all_kernels:
         cmd.extend(['-k', 'all'])
-    with util.RunInChroot(target) as in_chroot:
-        in_chroot(cmd)
+    util.subp(cmd, target=target)
 
 
 def copy_fstab(fstab, target):
@@ -533,7 +374,6 @@
 
 
 def apply_networking(target, state):
-    netstate = state.get('network_state')
     netconf = state.get('network_config')
     interfaces = state.get('interfaces')
 
@@ -544,22 +384,13 @@
                 return True
         return False
 
-    ns = None
-    if is_valid_src(netstate):
-        LOG.debug("applying network_state")
-        ns = net.network_state.from_state_file(netstate)
-    elif is_valid_src(netconf):
-        LOG.debug("applying network_config")
-        ns = net.parse_net_config(netconf)
-
-    if ns is not None:
-        net.render_network_state(target=target, network_state=ns)
+    if is_valid_src(netconf):
+        LOG.info("applying network_config")
+        apply_net.apply_net(target, network_state=None, network_config=netconf)
     else:
         LOG.debug("copying interfaces")
         copy_interfaces(interfaces, target)
 
-    _maybe_remove_legacy_eth0(target)
-
 
 def copy_interfaces(interfaces, target):
     if not interfaces:
@@ -704,8 +535,8 @@
 
         # FIXME: this assumes grub. need more generic way to update root=
         util.ensure_dir(os.path.sep.join([target, os.path.dirname(grub_dev)]))
-        with util.RunInChroot(target) as in_chroot:
-            in_chroot(['update-grub'])
+        with util.ChrootableTarget(target) as in_chroot:
+            in_chroot.subp(['update-grub'])
 
     else:
         LOG.warn("Not sure how this will boot")
@@ -740,7 +571,7 @@
     }
 
     needed_packages = []
-    installed_packages = get_installed_packages(target)
+    installed_packages = util.get_installed_packages(target)
     for cust_cfg, pkg_reqs in custom_configs.items():
         if cust_cfg not in cfg:
             continue
@@ -820,7 +651,7 @@
             name=stack_prefix, reporting_enabled=True, level="INFO",
             description="writing config files and configuring apt"):
         write_files(cfg, target)
-        apt_config(cfg, target)
+        do_apt_config(cfg, target)
         disable_overlayroot(cfg, target)
 
     # packages may be needed prior to installing kernel
@@ -834,8 +665,8 @@
         copy_mdadm_conf(mdadm_location, target)
         # as per https://bugs.launchpad.net/ubuntu/+source/mdadm/+bug/964052
         # reconfigure mdadm
-        util.subp(['chroot', target, 'dpkg-reconfigure',
-                   '--frontend=noninteractive', 'mdadm'], data=None)
+        util.subp(['dpkg-reconfigure', '--frontend=noninteractive', 'mdadm'],
+                  data=None, target=target)
 
     with events.ReportEventStack(
             name=stack_prefix, reporting_enabled=True, level="INFO",
@@ -843,7 +674,6 @@
         setup_zipl(cfg, target)
         install_kernel(cfg, target)
         run_zipl(cfg, target)
-        apply_debconf_selections(cfg, target)
 
         restore_dist_interfaces(cfg, target)
 
@@ -906,8 +736,4 @@
     populate_one_subcmd(parser, CMD_ARGUMENTS, curthooks)
 
 
-CONFIG_CLEANERS = {
-    'cloud-init': clean_cloud_init,
-}
-
 # vi: ts=4 expandtab syntax=python
 
=== modified file 'curtin/commands/main.py'
--- curtin/commands/main.py	2016-05-10 16:13:29 +0000
+++ curtin/commands/main.py	2016-10-03 18:55:20 +0000
@@ -26,9 +26,10 @@
 from ..deps import install_deps
 
 SUB_COMMAND_MODULES = [
-    'apply_net', 'block-meta', 'block-wipe', 'curthooks', 'extract',
-    'hook', 'in-target', 'install', 'mkfs', 'net-meta',
-    'pack', 'swap', 'system-install', 'system-upgrade']
+    'apply_net', 'block-info', 'block-meta', 'block-wipe', 'curthooks',
+    'clear-holders', 'extract', 'hook', 'in-target', 'install', 'mkfs',
+    'net-meta', 'apt-config', 'pack', 'swap', 'system-install',
+    'system-upgrade']
 
 
 def add_subcmd(subparser, subcmd):
 
=== modified file 'curtin/config.py'
--- curtin/config.py	2016-03-18 14:16:45 +0000
+++ curtin/config.py	2016-10-03 18:55:20 +0000
@@ -138,6 +138,5 @@
 
 
 def value_as_boolean(value):
-    if value in (False, None, '0', 0, 'False', 'false', ''):
-        return False
-    return True
+    false_values = (False, None, 0, '0', 'False', 'false', 'None', 'none', '')
+    return value not in false_values
 
=== added file 'curtin/gpg.py'
--- curtin/gpg.py	1970-01-01 00:00:00 +0000
+++ curtin/gpg.py	2016-10-03 18:55:20 +0000
@@ -0,0 +1,74 @@
+#   Copyright (C) 2016 Canonical Ltd.
+#
+#   Author: Scott Moser <[e-mail]>
+#           Christian Ehrhardt <[e-mail]>
+#
+#   Curtin is free software: you can redistribute it and/or modify it under
+#   the terms of the GNU Affero General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   Curtin is distributed in the hope that it will be useful, but WITHOUT ANY
+#   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#   FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+#   more details.
+#
+#   You should have received a copy of the GNU Affero General Public License
+#   along with Curtin.  If not, see <http://www.gnu.org/licenses/>.
+""" gpg.py
+gpg related utilities to get raw keys data by their id
+"""
+
+from curtin import util
+
+from .log import LOG
+
+
+def export_armour(key):
+    """Export gpg key, armoured key gets returned"""
+    try:
+        (armour, _) = util.subp(["gpg", "--export", "--armour", key],
+                                capture=True)
+    except util.ProcessExecutionError as error:
+        # debug, since it happens for any key not on the system initially
+        LOG.debug('Failed to export armoured key "%s": %s', key, error)
+        armour = None
+    return armour
+
+
+def recv_key(key, keyserver):
+    """Receive gpg key from the specified keyserver"""
+    LOG.debug('Receive gpg key "%s"', key)
+    try:
+        util.subp(["gpg", "--keyserver", keyserver, "--recv", key],
+                  capture=True)
+    except util.ProcessExecutionError as error:
+        raise ValueError(('Failed to import key "%s" '
+                          'from server "%s" - error %s') %
+                         (key, keyserver, error))
+
+
+def delete_key(key):
+    """Delete the specified key from the local gpg ring"""
+    try:
+        util.subp(["gpg", "--batch", "--yes", "--delete-keys", key],
+                  capture=True)
+    except util.ProcessExecutionError as error:
+        LOG.warn('Failed delete key "%s": %s', key, error)
+
+
+def getkeybyid(keyid, keyserver='keyserver.ubuntu.com'):
+    """get gpg keyid from keyserver"""
+    armour = export_armour(keyid)
+    if not armour:
+        try:
+            recv_key(keyid, keyserver=keyserver)
+            armour = export_armour(keyid)
+        except ValueError:
+            LOG.exception('Failed to obtain gpg key %s', keyid)
+            raise
+        finally:
+            # delete just imported key to leave environment as it was before
+            delete_key(keyid)
+
+    return armour
 
=== modified file 'curtin/net/__init__.py'
--- curtin/net/__init__.py	2016-10-03 18:00:41 +0000
+++ curtin/net/__init__.py	2016-10-03 18:55:20 +0000
@@ -299,7 +299,7 @@
             mac = iface.get('mac_address', '')
             # len(macaddr) == 2 * 6 + 5 == 17
             if ifname and mac and len(mac) == 17:
-                content += generate_udev_rule(ifname, mac)
+                content += generate_udev_rule(ifname, mac.lower())
 
     return content
 
@@ -349,7 +349,7 @@
         'subnets',
         'type',
     ]
-    if iface['type'] not in ['bond', 'bridge']:
+    if iface['type'] not in ['bond', 'bridge', 'vlan']:
         ignore_map.append('mac_address')
 
     for key, value in iface.items():
@@ -361,26 +361,52 @@
     return content
 
 
-def render_route(route):
-    content = "up route add"
+def render_route(route, indent=""):
+    """When rendering routes for an iface, in some cases applying a route
+    may result in the route command returning non-zero which produces
+    some confusing output for users manually using ifup/ifdown[1].  To
+    that end, we will optionally include an '|| true' postfix to each
+    route line allowing users to work with ifup/ifdown without using
+    --force option.
+
+    We may at somepoint not want to emit this additional postfix, and
+    add a 'strict' flag to this function.  When called with strict=True,
+    then we will not append the postfix.
+
+    1. http://askubuntu.com/questions/168033/
+             how-to-set-static-routes-in-ubuntu-server
+    """
+    content = []
+    up = indent + "post-up route add"
+    down = indent + "pre-down route del"
+    or_true = " || true"
     mapping = {
         'network': '-net',
         'netmask': 'netmask',
         'gateway': 'gw',
         'metric': 'metric',
     }
-    for k in ['network', 'netmask', 'gateway', 'metric']:
-        if k in route:
-            content += " %s %s" % (mapping[k], route[k])
-
-    content += '\n'
-    return content
-
-
-def iface_start_entry(iface, index):
+    if route['network'] == '0.0.0.0' and route['netmask'] == '0.0.0.0':
+        default_gw = " default gw %s" % route['gateway']
+        content.append(up + default_gw + or_true)
+        content.append(down + default_gw + or_true)
+    elif route['network'] == '::' and route['netmask'] == 0:
+        # ipv6!
+        default_gw = " -A inet6 default gw %s" % route['gateway']
+        content.append(up + default_gw + or_true)
+        content.append(down + default_gw + or_true)
+    else:
+        route_line = ""
+        for k in ['network', 'netmask', 'gateway', 'metric']:
+            if k in route:
+                route_line += " %s %s" % (mapping[k], route[k])
+        content.append(up + route_line + or_true)
+        content.append(down + route_line + or_true)
+    return "\n".join(content)
+
+
+def iface_start_entry(iface):
     fullname = iface['name']
-    if index != 0:
-        fullname += ":%s" % index
 
     control = iface['control']
     if control == "auto":
@@ -397,6 +423,16 @@
             "iface {fullname} {inet} {mode}\n").format(**subst)
 
 
+def subnet_is_ipv6(subnet):
+    # 'static6' or 'dhcp6'
+    if subnet['type'].endswith('6'):
+        # This is a request for DHCPv6.
+        return True
+    elif subnet['type'] == 'static' and ":" in subnet['address']:
+        return True
+    return False
+
+
 def render_interfaces(network_state):
     ''' Given state, emit etc/network/interfaces content '''
 
@@ -424,42 +460,43 @@
             content += "\n"
         subnets = iface.get('subnets', {})
         if subnets:
-            for index, subnet in zip(range(0, len(subnets)), subnets):
+            for index, subnet in enumerate(subnets):
                 if content[-2:] != "\n\n":
                     content += "\n"
                 iface['index'] = index
                 iface['mode'] = subnet['type']
                 iface['control'] = subnet.get('control', 'auto')
                 subnet_inet = 'inet'
-                if iface['mode'].endswith('6'):
-                    # This is a request for DHCPv6.
-                    subnet_inet += '6'
-                elif iface['mode'] == 'static' and ":" in subnet['address']:
-                    # This is a static IPv6 address.
+                if subnet_is_ipv6(subnet):
                     subnet_inet += '6'
                 iface['inet'] = subnet_inet
-                if iface['mode'].startswith('dhcp'):
+                if subnet['type'].startswith('dhcp'):
                     iface['mode'] = 'dhcp'
 
-                content += iface_start_entry(iface, index)
+                # do not emit multiple 'auto $IFACE' lines as older (precise)
+                # ifupdown complains
+                if "auto %s\n" % (iface['name']) in content:
+                    iface['control'] = 'alias'
+
+                content += iface_start_entry(iface)
                 content += iface_add_subnet(iface, subnet)
                 content += iface_add_attrs(iface, index)
-                if len(subnets) > 1 and index == 0:
-                    for i in range(1, len(subnets)):
-                        content += "    post-up ifup %s:%s\n" % (iface['name'],
-                                                                 i)
+
+                for route in subnet.get('routes', []):
+                    content += render_route(route, indent="    ") + '\n'
+
         else:
             # ifenslave docs say to auto the slave devices
-            if 'bond-master' in iface:
+            if 'bond-master' in iface or 'bond-slaves' in iface:
                 content += "auto {name}\n".format(**iface)
             content += "iface {name} {inet} {mode}\n".format(**iface)
-            content += iface_add_attrs(iface, index)
+            content += iface_add_attrs(iface, 0)
 
     for route in network_state.get('routes'):
         content += render_route(route)
 
     # global replacements until v2 format
-    content = content.replace('mac_address', 'hwaddress')
+    content = content.replace('mac_address', 'hwaddress ether')
 
     # Play nice with others and source eni config files
     content += "\nsource /etc/network/interfaces.d/*.cfg\n"
 
=== modified file 'curtin/net/network_state.py'
--- curtin/net/network_state.py	2015-10-02 16:19:07 +0000
+++ curtin/net/network_state.py	2016-10-03 18:55:20 +0000
@@ -121,6 +121,18 @@
         iface = interfaces.get(command['name'], {})
         for param, val in command.get('params', {}).items():
             iface.update({param: val})
+
+        # convert subnet ipv6 netmask to cidr as needed
+        subnets = command.get('subnets')
+        if subnets:
+            for subnet in subnets:
+                if subnet['type'] == 'static':
+                    if 'netmask' in subnet and ':' in subnet['address']:
+                        subnet['netmask'] = mask2cidr(subnet['netmask'])
+                        for route in subnet.get('routes', []):
+                            if 'netmask' in route:
+                                route['netmask'] = mask2cidr(route['netmask'])
+
         iface.update({
             'name': command.get('name'),
             'type': command.get('type'),
@@ -130,7 +142,7 @@
             'mtu': command.get('mtu'),
             'address': None,
             'gateway': None,
-            'subnets': command.get('subnets'),
+            'subnets': subnets,
         })
         self.network_state['interfaces'].update({command.get('name'): iface})
         self.dump_network_state()
@@ -141,6 +153,7 @@
             iface eth0.222 inet static
                     address 10.10.10.1
                     netmask 255.255.255.0
+                    hwaddress ether BC:76:4E:06:96:B3
                     vlan-raw-device eth0
         '''
         required_keys = [
@@ -332,6 +345,37 @@
     return ".".join([str(x) for x in mask])
 
 
+def ipv4mask2cidr(mask):
+    if '.' not in mask:
+        return mask
+    return sum([bin(int(x)).count('1') for x in mask.split('.')])
+
+
+def ipv6mask2cidr(mask):
+    if ':' not in mask:
+        return mask
+
+    bitCount = [0, 0x8000, 0xc000, 0xe000, 0xf000, 0xf800, 0xfc00, 0xfe00,
+                0xff00, 0xff80, 0xffc0, 0xffe0, 0xfff0, 0xfff8, 0xfffc,
+                0xfffe, 0xffff]
+    cidr = 0
+    for word in mask.split(':'):
+        if not word or int(word, 16) == 0:
+            break
+        cidr += bitCount.index(int(word, 16))
+
+    return cidr
+
+
+def mask2cidr(mask):
+    if ':' in mask:
+        return ipv6mask2cidr(mask)
+    elif '.' in mask:
+        return ipv4mask2cidr(mask)
+    else:
+        return mask
+
+
 if __name__ == '__main__':
     import sys
     import random
 
=== modified file 'curtin/util.py'
--- curtin/util.py	2016-10-03 18:00:41 +0000
+++ curtin/util.py	2016-10-03 18:55:20 +0000
@@ -16,18 +16,35 @@
 #   along with Curtin.  If not, see <http://www.gnu.org/licenses/>.
 
 import argparse
+import collections
 import errno
 import glob
 import json
 import os
 import platform
+import re
 import shutil
+import socket
 import subprocess
 import stat
 import sys
 import tempfile
 import time
 
+# avoid the dependency to python3-six as used in cloud-init
+try:
+    from urlparse import urlparse
+except ImportError:
+    # python3
+    # avoid triggering pylint, https://github.com/PyCQA/pylint/issues/769
+    # pylint:disable=import-error,no-name-in-module
+    from urllib.parse import urlparse
+
+try:
+    string_types = (basestring,)
+except NameError:
+    string_types = (str,)
+
 from .log import LOG
 
 _INSTALLED_HELPERS_PATH = '/usr/lib/curtin/helpers'
@@ -35,14 +52,22 @@
 
 _LSB_RELEASE = {}
 
+_DNS_REDIRECT_IP = None
+
+# matcher used in template rendering functions
+BASIC_MATCHER = re.compile(r'\$\{([A-Za-z0-9_.]+)\}|\$([A-Za-z0-9_.]+)')
+
 
 def _subp(args, data=None, rcs=None, env=None, capture=False, shell=False,
-          logstring=False, decode="replace"):
+          logstring=False, decode="replace", target=None):
     if rcs is None:
         rcs = [0]
 
     devnull_fp = None
     try:
+        if target_path(target) != "/":
+            args = ['chroot', target] + list(args)
+
         if not logstring:
             LOG.debug(("Running command %s with allowed return codes %s"
                        " (shell=%s, capture=%s)"), args, rcs, shell, capture)
@@ -118,6 +143,8 @@
         a list of times to sleep in between retries.  After each failure
         subp will sleep for N seconds and then try again.  A value of [1, 3]
         means to run, sleep 1, run, sleep 3, run and then return exit code.
+    :param target:
+        run the command as 'chroot target <args>'
     """
     retries = []
     if "retries" in kwargs:
@@ -277,15 +304,29 @@
 
 
 def write_file(filename, content, mode=0o644, omode="w"):
+    """
+    write 'content' to file at 'filename' using python open mode 'omode'.
+    if mode is not set, then chmod file to mode. mode is 644 by default
+    """
     ensure_dir(os.path.dirname(filename))
     with open(filename, omode) as fp:
         fp.write(content)
-    os.chmod(filename, mode)
-
-
-def load_file(path, mode="r"):
+    if mode:
+        os.chmod(filename, mode)
+
+
+def load_file(path, mode="r", read_len=None, offset=0):
     with open(path, mode) as fp:
-        return fp.read()
+        if offset:
+            fp.seek(offset)
+        return fp.read(read_len) if read_len else fp.read()
+
+
+def file_size(path):
+    """get the size of a file"""
+    with open(path, 'rb') as fp:
+        fp.seek(0, 2)
+        return fp.tell()
 
 
 def del_file(path):
@@ -311,7 +352,7 @@
          'done',
          ''])
 
-    fpath = os.path.join(target, "usr/sbin/policy-rc.d")
+    fpath = target_path(target, "/usr/sbin/policy-rc.d")
 
     if os.path.isfile(fpath):
         return False
@@ -322,7 +363,7 @@
 
 def undisable_daemons_in_root(target):
     try:
-        os.unlink(os.path.join(target, "usr/sbin/policy-rc.d"))
+        os.unlink(target_path(target, "/usr/sbin/policy-rc.d"))
     except OSError as e:
         if e.errno != errno.ENOENT:
             raise
@@ -334,7 +375,7 @@
     def __init__(self, target, allow_daemons=False, sys_resolvconf=True):
         if target is None:
             target = "/"
-        self.target = os.path.abspath(target)
+        self.target = target_path(target)
         self.mounts = ["/dev", "/proc", "/sys"]
         self.umounts = []
         self.disabled_daemons = False
@@ -344,20 +385,21 @@
 
     def __enter__(self):
         for p in self.mounts:
-            tpath = os.path.join(self.target, p[1:])
+            tpath = target_path(self.target, p)
             if do_mount(p, tpath, opts='--bind'):
                 self.umounts.append(tpath)
 
         if not self.allow_daemons:
             self.disabled_daemons = disable_daemons_in_root(self.target)
 
-        target_etc = os.path.join(self.target, "etc")
+        rconf = target_path(self.target, "/etc/resolv.conf")
+        target_etc = os.path.dirname(rconf)
         if self.target != "/" and os.path.isdir(target_etc):
             # never muck with resolv.conf on /
             rconf = os.path.join(target_etc, "resolv.conf")
             rtd = None
             try:
-                rtd = tempfile.mkdtemp(dir=os.path.dirname(rconf))
+                rtd = tempfile.mkdtemp(dir=target_etc)
                 tmp = os.path.join(rtd, "resolv.conf")
                 os.rename(rconf, tmp)
                 self.rconf_d = rtd
@@ -375,25 +417,23 @@
             undisable_daemons_in_root(self.target)
 
         # if /dev is to be unmounted, udevadm settle (LP: #1462139)
-        if os.path.join(self.target, "dev") in self.umounts:
+        if target_path(self.target, "/dev") in self.umounts:
             subp(['udevadm', 'settle'])
 
         for p in reversed(self.umounts):
             do_umount(p)
 
-        rconf = os.path.join(self.target, "etc", "resolv.conf")
+        rconf = target_path(self.target, "/etc/resolv.conf")
         if self.sys_resolvconf and self.rconf_d:
             os.rename(os.path.join(self.rconf_d, "resolv.conf"), rconf)
             shutil.rmtree(self.rconf_d)
 
+    def subp(self, *args, **kwargs):
+        kwargs['target'] = self.target
+        return subp(*args, **kwargs)
 
-class RunInChroot(ChrootableTarget):
-    def __call__(self, args, **kwargs):
-        if self.target != "/":
-            chroot = ["chroot", self.target]
-        else:
-            chroot = []
-        return subp(chroot + args, **kwargs)
+    def path(self, path):
+        return target_path(self.target, path)
 
 
 def is_exe(fpath):
@@ -402,14 +442,13 @@
 
 
 def which(program, search=None, target=None):
-    if target is None or os.path.realpath(target) == "/":
-        target = "/"
+    target = target_path(target)
 
     if os.path.sep in program:
         # if program had a '/' in it, then do not search PATH
         # 'which' does consider cwd here. (cd / && which bin/ls) = bin/ls
         # so effectively we set cwd to / (or target)
-        if is_exe(os.path.sep.join((target, program,))):
+        if is_exe(target_path(target, program)):
             return program
 
     if search is None:
@@ -424,8 +463,9 @@
     search = [os.path.abspath(p) for p in search]
 
     for path in search:
-        if is_exe(os.path.sep.join((target, path, program,))):
-            return os.path.sep.join((path, program,))
+        ppath = os.path.sep.join((path, program))
+        if is_exe(target_path(target, ppath)):
+            return ppath
 
     return None
 
@@ -467,33 +507,39 @@
 
 
 def get_architecture(target=None):
-    chroot = []
-    if target is not None:
-        chroot = ['chroot', target]
-    out, _ = subp(chroot + ['dpkg', '--print-architecture'],
-                  capture=True)
+    out, _ = subp(['dpkg', '--print-architecture'], capture=True,
+                  target=target)
     return out.strip()
 
 
 def has_pkg_available(pkg, target=None):
-    chroot = []
-    if target is not None:
-        chroot = ['chroot', target]
-    out, _ = subp(chroot + ['apt-cache', 'pkgnames'], capture=True)
+    out, _ = subp(['apt-cache', 'pkgnames'], capture=True, target=target)
     for item in out.splitlines():
         if pkg == item.strip():
             return True
     return False
 
 
+def get_installed_packages(target=None):
+    (out, _) = subp(['dpkg-query', '--list'], target=target, capture=True)
+
+    pkgs_inst = set()
+    for line in out.splitlines():
+        try:
+            (state, pkg, other) = line.split(None, 2)
+        except ValueError:
+            continue
+        if state.startswith("hi") or state.startswith("ii"):
+            pkgs_inst.add(re.sub(":.*", "", pkg))
+
+    return pkgs_inst
+
+
 def has_pkg_installed(pkg, target=None):
-    chroot = []
-    if target is not None:
-        chroot = ['chroot', target]
     try:
-        out, _ = subp(chroot + ['dpkg-query', '--show', '--showformat',
-                                '${db:Status-Abbrev}', pkg],
-                      capture=True)
+        out, _ = subp(['dpkg-query', '--show', '--showformat',
+                       '${db:Status-Abbrev}', pkg],
+                      capture=True, target=target)
         return out.rstrip() == "ii"
     except ProcessExecutionError:
         return False
@@ -542,13 +588,9 @@
     """Use dpkg-query to extract package pkg's version string
        and parse the version string into a dictionary
     """
-    chroot = []
-    if target is not None:
-        chroot = ['chroot', target]
     try:
-        out, _ = subp(chroot + ['dpkg-query', '--show', '--showformat',
-                                '${Version}', pkg],
-                      capture=True)
+        out, _ = subp(['dpkg-query', '--show', '--showformat',
+                       '${Version}', pkg], capture=True, target=target)
         raw = out.rstrip()
         return parse_dpkg_version(raw, name=pkg, semx=semx)
     except ProcessExecutionError:
@@ -600,11 +642,11 @@
     if comment.endswith("\n"):
         comment = comment[:-1]
 
-    marker = os.path.join(target, marker)
+    marker = target_path(target, marker)
     # if marker exists, check if there are files that would make it obsolete
-    listfiles = [os.path.join(target, "etc/apt/sources.list")]
+    listfiles = [target_path(target, "/etc/apt/sources.list")]
     listfiles += glob.glob(
-        os.path.join(target, "etc/apt/sources.list.d/*.list"))
+        target_path(target, "etc/apt/sources.list.d/*.list"))
 
     if os.path.exists(marker) and not force:
         if len(find_newer(marker, listfiles)) == 0:
@@ -612,7 +654,7 @@
 
     restore_perms = []
 
-    abs_tmpdir = tempfile.mkdtemp(dir=os.path.join(target, 'tmp'))
+    abs_tmpdir = tempfile.mkdtemp(dir=target_path(target, "/tmp"))
     try:
         abs_slist = abs_tmpdir + "/sources.list"
         abs_slistd = abs_tmpdir + "/sources.list.d"
@@ -621,8 +663,8 @@
         ch_slistd = ch_tmpdir + "/sources.list.d"
 
         # this file gets executed on apt-get update sometimes. (LP: #1527710)
-        motd_update = os.path.join(
-            target, "usr/lib/update-notifier/update-motd-updates-available")
+        motd_update = target_path(
+            target, "/usr/lib/update-notifier/update-motd-updates-available")
         pmode = set_unexecutable(motd_update)
         if pmode is not None:
             restore_perms.append((motd_update, pmode),)
@@ -647,8 +689,8 @@
             'update']
 
         # do not using 'run_apt_command' so we can use 'retries' to subp
-        with RunInChroot(target, allow_daemons=True) as inchroot:
-            inchroot(update_cmd, env=env, retries=retries)
+        with ChrootableTarget(target, allow_daemons=True) as inchroot:
+            inchroot.subp(update_cmd, env=env, retries=retries)
     finally:
         for fname, perms in restore_perms:
             os.chmod(fname, perms)
@@ -685,9 +727,8 @@
         return env, cmd
 
     apt_update(target, env=env, comment=' '.join(cmd))
-    ric = RunInChroot(target, allow_daemons=allow_daemons)
-    with ric as inchroot:
-        return inchroot(cmd, env=env)
+    with ChrootableTarget(target, allow_daemons=allow_daemons) as inchroot:
+        return inchroot.subp(cmd, env=env)
 
 
 def system_upgrade(aptopts=None, target=None, env=None, allow_daemons=False):
@@ -716,7 +757,7 @@
     """
     Look for "hook" in "target" and run it
     """
-    target_hook = os.path.join(target, 'curtin', hook)
+    target_hook = target_path(target, '/curtin/' + hook)
     if os.path.isfile(target_hook):
         LOG.debug("running %s" % target_hook)
         subp([target_hook])
@@ -828,6 +869,18 @@
     return val
 
 
+def bytes2human(size):
+    """convert size in bytes to human readable"""
+    if not (isinstance(size, (int, float)) and
+            int(size) == size and
+            int(size) >= 0):
+        raise ValueError('size must be a integral value')
+    mpliers = {'B': 1, 'K': 2 ** 10, 'M': 2 ** 20, 'G': 2 ** 30, 'T': 2 ** 40}
+    unit_order = sorted(mpliers, key=lambda x: -1 * mpliers[x])
+    unit = next((u for u in unit_order if (size / mpliers[u]) >= 1), 'B')
+    return str(int(size / mpliers[unit])) + unit
+
+
 def import_module(import_str):
     """Import a module."""
     __import__(import_str)
@@ -843,30 +896,42 @@
 
 
 def is_file_not_found_exc(exc):
-    return (isinstance(exc, IOError) and exc.errno == errno.ENOENT)
-
-
-def lsb_release():
+    return (isinstance(exc, (IOError, OSError)) and
+            hasattr(exc, 'errno') and
+            exc.errno in (errno.ENOENT, errno.EIO, errno.ENXIO))
+
+
+def _lsb_release(target=None):
     fmap = {'Codename': 'codename', 'Description': 'description',
             'Distributor ID': 'id', 'Release': 'release'}
+
+    data = {}
+    try:
+        out, _ = subp(['lsb_release', '--all'], capture=True, target=target)
+        for line in out.splitlines():
+            fname, _, val = line.partition(":")
+            if fname in fmap:
+                data[fmap[fname]] = val.strip()
+        missing = [k for k in fmap.values() if k not in data]
+        if len(missing):
+            LOG.warn("Missing fields in lsb_release --all output: %s",
+                     ','.join(missing))
+
+    except ProcessExecutionError as err:
+        LOG.warn("Unable to get lsb_release --all: %s", err)
+        data = {v: "UNAVAILABLE" for v in fmap.values()}
+
+    return data
+
+
+def lsb_release(target=None):
+    if target_path(target) != "/":
+        # do not use or update cache if target is provided
+        return _lsb_release(target)
+
     global _LSB_RELEASE
     if not _LSB_RELEASE:
-        data = {}
-        try:
-            out, err = subp(['lsb_release', '--all'], capture=True)
-            for line in out.splitlines():
-                fname, tok, val = line.partition(":")
-                if fname in fmap:
-                    data[fmap[fname]] = val.strip()
-            missing = [k for k in fmap.values() if k not in data]
-            if len(missing):
-                LOG.warn("Missing fields in lsb_release --all output: %s",
-                         ','.join(missing))
-
-        except ProcessExecutionError as e:
-            LOG.warn("Unable to get lsb_release --all: %s", e)
-            data = {v: "UNAVAILABLE" for v in fmap.values()}
-
+        data = _lsb_release()
         _LSB_RELEASE.update(data)
     return _LSB_RELEASE
 
@@ -881,8 +946,7 @@
 
 
 def json_dumps(data):
-    return json.dumps(data, indent=1, sort_keys=True,
-                      separators=(',', ': ')).encode('utf-8')
+    return json.dumps(data, indent=1, sort_keys=True, separators=(',', ': '))
 
 
 def get_platform_arch():
@@ -895,4 +959,137 @@
     }
     return platform2arch.get(platform.machine(), platform.machine())
 
+
+def basic_template_render(content, params):
+    """This does simple replacement of bash variable like templates.
+
+    It identifies patterns like ${a} or $a and can also identify patterns like
+    ${a.b} or $a.b which will look for a key 'b' in the dictionary rooted
+    by key 'a'.
+    """
+
+    def replacer(match):
+        """ replacer
+            replacer used in regex match to replace content
+        """
+        # Only 1 of the 2 groups will actually have a valid entry.
+        name = match.group(1)
+        if name is None:
+            name = match.group(2)
+        if name is None:
+            raise RuntimeError("Match encountered but no valid group present")
+        path = collections.deque(name.split("."))
+        selected_params = params
+        while len(path) > 1:
+            key = path.popleft()
+            if not isinstance(selected_params, dict):
+                raise TypeError("Can not traverse into"
+                                " non-dictionary '%s' of type %s while"
+                                " looking for subkey '%s'"
+                                % (selected_params,
+                                   selected_params.__class__.__name__,
+                                   key))
+            selected_params = selected_params[key]
+        key = path.popleft()
+        if not isinstance(selected_params, dict):
+            raise TypeError("Can not extract key '%s' from non-dictionary"
+                            " '%s' of type %s"
+                            % (key, selected_params,
+                               selected_params.__class__.__name__))
+        return str(selected_params[key])
+
+    return BASIC_MATCHER.sub(replacer, content)
+
+
+def render_string(content, params):
+    """ render_string
+        render a string following replacement rules as defined in
+        basic_template_render returning the string
+    """
+    if not params:
+        params = {}
+    return basic_template_render(content, params)
+
+
+def is_resolvable(name):
+    """determine if a url is resolvable, return a boolean
+    This also attempts to be resilent against dns redirection.
+
+    Note, that normal nsswitch resolution is used here.  So in order
+    to avoid any utilization of 'search' entries in /etc/resolv.conf
+    we have to append '.'.
+
+    The top level 'invalid' domain is invalid per RFC.  And example.com
+    should also not exist.  The random entry will be resolved inside
+    the search list.
+    """
+    global _DNS_REDIRECT_IP
+    if _DNS_REDIRECT_IP is None:
+        badips = set()
+        badnames = ("does-not-exist.example.com.", "example.invalid.")
+        badresults = {}
+        for iname in badnames:
+            try:
+                result = socket.getaddrinfo(iname, None, 0, 0,
+                                            socket.SOCK_STREAM,
+                                            socket.AI_CANONNAME)
+                badresults[iname] = []
+                for (_, _, _, cname, sockaddr) in result:
+                    badresults[iname].append("%s: %s" % (cname, sockaddr[0]))
+                    badips.add(sockaddr[0])
+            except (socket.gaierror, socket.error):
+                pass
+        _DNS_REDIRECT_IP = badips
+        if badresults:
+            LOG.debug("detected dns redirection: %s", badresults)
+
+    try:
+        result = socket.getaddrinfo(name, None)
+        # check first result's sockaddr field
+        addr = result[0][4][0]
+        if addr in _DNS_REDIRECT_IP:
+            LOG.debug("dns %s in _DNS_REDIRECT_IP", name)
+            return False
+        LOG.debug("dns %s resolved to '%s'", name, result)
+        return True
+    except (socket.gaierror, socket.error):
+        LOG.debug("dns %s failed to resolve", name)
+        return False
+
+
+def is_resolvable_url(url):
+    """determine if this url is resolvable (existing or ip)."""
+    return is_resolvable(urlparse(url).hostname)
+
+
+def target_path(target, path=None):
+    # return 'path' inside target, accepting target as None
+    if target in (None, ""):
+        target = "/"
+    elif not isinstance(target, string_types):
+        raise ValueError("Unexpected input for target: %s" % target)
+    else:
+        target = os.path.abspath(target)
+        # abspath("//") returns "//" specifically for 2 slashes.
+        if target.startswith("//"):
+            target = target[1:]
+
+    if not path:
+        return target
+
+    # os.path.join("/etc", "/foo") returns "/foo". Chomp all leading /.
+    while len(path) and path[0] == "/":
+        path = path[1:]
+
+    return os.path.join(target, path)
+
+
+class RunInChroot(ChrootableTarget):
+    """Backwards compatibility for RunInChroot (LP: #1617375).
+    It needs to work like:
+        with RunInChroot("/target") as in_chroot:
+            in_chroot(["your", "chrooted", "command"])"""
+    __call__ = ChrootableTarget.subp
+
+
 # vi: ts=4 expandtab syntax=python
 
=== modified file 'debian/changelog'
--- debian/changelog	2016-10-03 17:23:32 +0000
+++ debian/changelog	2016-10-03 18:55:20 +0000
@@ -1,8 +1,38 @@
-curtin (0.1.0~bzr399-0ubuntu1~16.04.1ubuntu1) UNRELEASED; urgency=medium
+curtin (0.1.0~bzr425-0ubuntu1~16.04.1) xenial-proposed; urgency=medium
 
+  [ Scott Moser ]
   * debian/new-upstream-snapshot: add writing of debian changelog entries. 
 
- -- Scott Moser <[e-mail]>  Mon, 03 Oct 2016 13:23:11 -0400
+  [ Ryan Harper ]
+  * New upstream snapshot.
+    - unittest,tox.ini: catch and fix issue with trusty-level mock of open 
+    - block/mdadm: add option to ignore mdadm_assemble errors  (LP: #1618429)
+    - curtin/doc: overhaul curtin documentation for readthedocs.org  (LP: #1351085)
+    - curtin.util: re-add support for RunInChroot  (LP: #1617375)
+    - curtin/net: overhaul of eni rendering to handle mixed ipv4/ipv6 configs 
+    - curtin.block: refactor clear_holders logic into block.clear_holders and cli cmd 
+    - curtin.apply_net should exit non-zero upon exception.  (LP: #1615780)
+    - apt: fix bug in disable_suites if sources.list line is blank. 
+    - vmtests: disable Wily in vmtests 
+    - Fix the unittests for test_apt_source. 
+    - get CURTIN_VMTEST_PARALLEL shown correctly in jenkins-runner output 
+    - fix vmtest check_file_strippedline to strip lines before comparing 
+    - fix whitespace damage in tests/vmtests/__init__.py 
+    - fix dpkg-reconfigure when debconf_selections was provided.  (LP: #1609614)
+    - fix apt tests on non-intel arch 
+    - Add apt features to curtin.  (LP: #1574113)
+    - vmtest: easier use of parallel and controlling timeouts 
+    - mkfs.vfat: add force flag for formating whole disks  (LP: #1597923)
+    - block.mkfs: fix sectorsize flag  (LP: #1597522)
+    - block_meta: cleanup use of sys_block_path and handle cciss knames  (LP: #1562249)
+    - block.get_blockdev_sector_size: handle _lsblock multi result return  (LP: #1598310)
+    - util: add target (chroot) support to subp, add target_path helper. 
+    - block_meta: fallback to parted if blkid does not produce output  (LP: #1524031)
+    - commands.block_wipe:  correct default wipe mode to 'superblock' 
+    - tox.ini: run coverage normally rather than separately 
+    - move uefi boot knowledge from launch and vmtest to xkvm 
+
+ -- Ryan Harper <[e-mail]>  Mon, 03 Oct 2016 13:43:54 -0500
 
 curtin (0.1.0~bzr399-0ubuntu1~16.04.1) xenial-proposed; urgency=medium
 
 
=== modified file 'doc/conf.py'
--- doc/conf.py	2015-10-02 16:19:07 +0000
+++ doc/conf.py	2016-10-03 18:55:20 +0000
@@ -13,6 +13,11 @@
 
 import sys, os
 
+# Fix path so we can import curtin.__version__
+sys.path.insert(1, os.path.realpath(os.path.join(
+                                    os.path.dirname(__file__), '..')))
+import curtin
+
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
@@ -41,16 +46,16 @@
 
 # General information about the project.
 project = u'curtin'
-copyright = u'2013, Scott Moser'
+copyright = u'2016, Scott Moser, Ryan Harper'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
 #
 # The short X.Y version.
-version = '0.3'
+version = curtin.__version__
 # The full version, including alpha/beta/rc tags.
-release = '0.3'
+release = version
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
@@ -93,6 +98,18 @@
 # a list of builtin themes.
 html_theme = 'classic'
 
+# on_rtd is whether we are on readthedocs.org, this line of code grabbed from
+# docs.readthedocs.org
+on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
+
+if not on_rtd:  # only import and set the theme if we're building docs locally
+    import sphinx_rtd_theme
+    html_theme = 'sphinx_rtd_theme'
+    html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
+
+# otherwise, readthedocs.org uses their theme by default, so no need to specify
+# it
+
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
@@ -120,7 +137,7 @@
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['static']
+#html_static_path = ['static']
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
 
=== removed file 'doc/devel/README-vmtest.txt'
--- doc/devel/README-vmtest.txt	2016-02-12 21:54:46 +0000
+++ doc/devel/README-vmtest.txt	1970-01-01 00:00:00 +0000
@@ -1,152 +0,0 @@
-== Background ==
-Curtin includes a mechanism called 'vmtest' that allows it to actually
-do installs and validate a number of configurations.
-
-The general flow of the vmtests is:
- 1. each test has an associated yaml config file for curtin in examples/tests
- 2. uses curtin-pack to create the user-data for cloud-init to trigger install
- 3. create and install a system using 'tools/launch'.
-    3.1 The install environment is booted from a maas ephemeral image.
-    3.2 kernel & initrd used are from maas images (not part of the image)
-    3.3 network by default is handled via user networking
-    3.4 It creates all empty disks required
-    3.5 cloud-init datasource is provided by launch
-      a) like: ds=nocloud-net;seedfrom=http://10.7.0.41:41518/
-         provided by python webserver start_http
-      b) via -drive file=/tmp/launch.8VOiOn/seed.img,if=virtio,media=cdrom
-         as a seed disk (if booted without external kernel)
-    3.6 dependencies and other preparations are installed at the beginning by
-        curtin inside the ephemeral image prior to configuring the target
- 4. power off the system.
- 5. configure a 'NoCloud' datasource seed image that provides scripts that
-    will run on first boot.
-    5.1 this will contain all our code to gather health data on the install
-    5.2 by cloud-init design this runs only once per instance, if you start
-        the system again this won't be called again
- 6. boot the installed system with 'tools/xkvm'.
-    6.1 reuses the disks that were installed/configured in the former steps
-    6.2 also adds an output disk
-    6.3 additionally the seed image for the data gathering is added
-    6.4 On this boot it will run the provided scripts, write their output to a
-        "data" disk and then shut itself down.
- 7. extract the data from the output disk
- 8. vmtest python code now verifies if the output is as expected.
-
-== Debugging ==
-At 3.1
-  - one can pull data out of the maas image with
-    sudo mount-image-callback your.img -- sh -c 'COMMAND'
-    e.g. sudo mount-image-callback your.img -- sh -c 'cp $MOUNTPOINT/boot/* .'
-At step 3.6 -> 4.
-  - tools/launch can be called in a way to give you console access
-    to do so just call tools/launch but drop the -serial=x parameter.
-    One might want to change "'power_state': {'mode': 'poweroff'}" to avoid
-    the auto reboot before getting control
-    Replace the directory usually seen in the launch calls with a clean fresh
-    directory
-  - In /curtin curtin and its config can be found
-  - if the system gets that far cloud-init will create a user ubuntu/passw0rd
-  - otherwise one can use a cloud-image from  https://cloud-images.ubuntu.com/
-    and add a backdoor user via
-    bzr branch lp:~maas-maintainers/maas/backdoor-image backdoor-image
-    sudo ./backdoor-image -v --user=<USER> --password-auth --password=<PW> IMG
-At step 6 -> 7
-  - You might want to keep all the temporary images around.
-    To do so you can set CURTIN_VMTEST_KEEP_DATA_PASS=all:
-    export CURTIN_VMTEST_KEEP_DATA_PASS=all CURTIN_VMTEST_KEEP_DATA_FAIL=all
-    That will keep the /tmp/tmpXXXXX directories and all files in there for
-    further execution.
-At step 7
-  - You might want to take a look at the output disk yourself.
-    It is a normal qcow image, so one can use mount-image-callback as described
-    above
-  - to invoke xkvm on your own take the command you see in the output and
-    remove the "-serial ..." but add -nographic instead
-    For graphical console one can add --vnc 127.0.0.1:1
-
-== Setup ==
-In order to run vmtest you'll need some dependencies.  To get them, you 
-can run:
-  make vmtest-deps
-
-That will install all necessary dependencies.
-
-== Running ==
-Running tests is done most simply by:
-
-  make vmtest
-
-If you wish to all tests in test_network.py, do so with:
-  sudo PATH=$PWD/tools:$PATH nosetests3 tests/vmtests/test_network.py
-
-Or run a single test with:
-  sudo PATH=$PWD/tools:$PATH nosetests3 tests/vmtests/test_network.py:WilyTestBasic
-
-Note:
-  * currently, the tests have to run as root.  The reason for this is that
-    the kernel and initramfs to boot are extracted from the maas ephemeral
-    image.  This should be fixed at some point, and then 'make vmtest'
-
-    The tests themselves don't actually have to run as root, but the
-    test setup does.
-  * the 'tools' directory must be in your path.
-  * test will set apt_proxy in the guests to the value of
-    'apt_proxy' environment variable.  If that is not set it will 
-    look at the host's apt config and read 'Acquire::HTTP::Proxy'
-
-== Environment Variables ==
-Some environment variables affect the running of vmtest
-  * apt_proxy: 
-    test will set apt_proxy in the guests to the value of 'apt_proxy'.
-    If that is not set it will look at the host's apt config and read
-    'Acquire::HTTP::Proxy'
-
-  * CURTIN_VMTEST_KEEP_DATA_PASS CURTIN_VMTEST_KEEP_DATA_FAIL:
-    default:
-      CURTIN_VMTEST_KEEP_DATA_PASS=none
-      CURTIN_VMTEST_KEEP_DATA_FAIL=all
-    These 2 variables determine what portions of the temporary
-    test data are kept.
-
-    The variables contain a comma ',' delimited list of directories
-    that should be kept in the case of pass or fail.  Additionally,
-    the values 'all' and 'none' are accepted.
-
-    Each vmtest that runs has its own sub-directory under the top level
-    CURTIN_VMTEST_TOPDIR.  In that directory are directories:
-      boot: inputs to the system boot (after install)
-      install: install phase related files
-      disks: the disks used for installation and boot
-      logs: install and boot logs
-      collect: data collected by the boot phase
-
-  * CURTIN_VMTEST_TOPDIR: default $TMPDIR/vmtest-<timestamp>
-    vmtest puts all test data under this value.  By default, it creates
-    a directory in TMPDIR (/tmp) named with as "vmtest-<timestamp>"
-
-    If you set this value, you must ensure that the directory is either
-    non-existant or clean.
-
-  * CURTIN_VMTEST_LOG: default $TMPDIR/vmtest-<timestamp>.log
-    vmtest writes extended log information to this file.
-    The default puts the log along side the TOPDIR.
-
-  * CURTIN_VMTEST_IMAGE_SYNC: default false (boolean)
-    if set to true, each run will attempt a sync of images.
-    If you want to make sure images are always up to date, then set to true.
-
-  * CURTIN_VMTEST_BRIDGE: default 'user'
-    the network devices will be attached to this bridge.  The default is
-    'user', which means to use qemu user mode networking.  Set it to
-    'virbr0' or 'lxcbr0' to use those bridges and then be able to ssh
-    in directly.
-
-  * IMAGE_DIR: default /srv/images
-    vmtest keeps a mirror of maas ephemeral images in this directory.
-
-  * IMAGES_TO_KEEP: default 1
-    keep this number of images of each release in the IMAGE_DIR.
-
-Environment 'boolean' values:
-   For boolean environment variables the value is considered True
-   if it is any value other than case insensitive 'false', '' or "0"
 
=== removed file 'doc/devel/README.txt'
--- doc/devel/README.txt	2015-03-11 13:19:43 +0000
+++ doc/devel/README.txt	1970-01-01 00:00:00 +0000
@@ -1,55 +0,0 @@
-## curtin development ##
-
-This document describes how to use kvm and ubuntu cloud images
-to develop curtin or test install configurations inside kvm.
-
-## get some dependencies ##
-sudo apt-get -qy install kvm libvirt-bin cloud-utils bzr
-
-## get cloud image to boot (-disk1.img) and one to install (-root.tar.gz)
-mkdir -p ~/download
-DLDIR=$( cd ~/download && pwd )
-rel="trusty"
-arch=amd64
-burl="http://cloud-images.ubuntu.com/$rel/current/"
-for f in $rel-server-cloudimg-${arch}-root.tar.gz $rel-server-cloudimg-${arch}-disk1.img; do
-  wget "$burl/$f" -O $DLDIR/$f; done
-( cd $DLDIR && qemu-img convert -O qcow $rel-server-cloudimg-${arch}-disk1.img $rel-server-cloudimg-${arch}-disk1.qcow2)
-
-BOOTIMG="$DLDIR/$rel-server-cloudimg-${arch}-disk1.qcow2"
-ROOTTGZ="$DLDIR/$rel-server-cloudimg-${arch}-root.tar.gz"
-
-## get curtin
-mkdir -p ~/src
-bzr init-repo ~/src/curtin
-( cd ~/src/curtin && bzr  branch lp:curtin trunk.dist )
-( cd ~/src/curtin && bzr branch trunk.dist trunk )
-
-## work with curtin
-cd ~/src/curtin/trunk
-# use 'launch' to launch a kvm instance with user data to pack
-# up local curtin and run it inside instance.
-./tools/launch $BOOTIMG --publish $ROOTTGZ -- curtin install "PUBURL/${ROOTTGZ##*/}"
-
-## notes about 'launch' ##
- * launch has --help so you can see that for some info.
- * '--publish' adds a web server at ${HTTP_PORT:-9923}
-   and puts the files you want available there.  You can reference
-   this url in config or cmdline with 'PUBURL'.  For example
-   '--publish foo.img' will put 'foo.img' at PUBURL/foo.img.
- * launch sets 'ubuntu' user password to 'passw0rd'
- * launch runs 'kvm -curses'
-   kvm -curses keyboard info:
-     'alt-2' to go to qemu console
- * launch puts serial console to 'serial.log' (look there for stuff)
- * when logged in
-   * you can look at /var/log/cloud-init-output.log
-   * archive should be extracted in /curtin
-   * shell archive should be in /var/lib/cloud/instance/scripts/part-002
- * when logged in, and archive available at
-
-
-## other notes ##
- * need to add '--install-deps' or something for curtin
-   cloud-image in 12.04 has no 'python3'
-   ideally 'curtin --install-deps install' would get the things it needs
 
=== added file 'doc/devel/clear_holders_doc.txt'
--- doc/devel/clear_holders_doc.txt	1970-01-01 00:00:00 +0000
+++ doc/devel/clear_holders_doc.txt	2016-10-03 18:55:20 +0000
@@ -0,0 +1,85 @@
+The new version of clear_holders is based around a data structure called a
+holder_tree which represents the current storage hirearchy above a specified
+starting device. Each node in a holders tree contains data about the node and a
+key 'holders' which contains a list of all nodes that depend on it. The keys in
+a holdres_tree node are:
+  - device: the path to the device in /sys/class/block
+  - dev_type: what type of storage layer the device is. possible values:
+      - disk
+      - lvm
+      - crypt
+      - raid
+      - bcache
+      - disk
+  - name: the kname of the device (used for display)
+  - holders: holders_trees for devices depending on the current device
+
+A holders tree can be generated for a device using the function
+clear_holders.gen_holders_tree. The device can be specified either as a path in
+/sys/class/block or as a path in /dev.
+
+The new implementation of block.clear_holders shuts down storage devices in a
+holders tree starting from the leaves of the tree and ascending towards the
+root. The old implementation of clear_holders ascended up each path of the tree
+separately, in a pattern similar to depth first search. The problem with the
+old implementation is that in some cases either an attempt would be made to
+remove one storage device while other devices depended on it or clear_holders
+would attempt to shut down the same storage device several times. In order to
+cope with this the old version of clear_holders had logic to handle expected
+failures and hope for the best moving forward. The new version of clear_holders
+is able to run without many anticipated failures.
+
+The logic to plan what order to shut down storage layers in is in
+clear_holders.plan_shutdown_holders_trees. This function accepts either a
+single holders tree or a list of holders trees. When run with a list of holders
+trees, it assumes that all of these trees start at basically the same layer in
+the overall storage hirearcy for the system (i.e. a list of holders trees
+starting from all of the target installation disks). This function returns a
+list of dictionaries, with each dictionary containing the keys:
+  - device: the path to the device in /sys/class/block
+  - dev_type: what type of storage layer the device is. possible values:
+      - disk
+      - lvm
+      - crypt
+      - raid
+      - bcache
+      - disk
+  - level: the level of the device in the current storage hirearchy
+           (starting from 0)
+
+The items in the list returned by clear_holders.plan_shutdown_holders_trees
+should be processed in order to make sure the holders trees are shutdown fully
+
+The main interface for clear_holders is the function
+clear_holders.clear_holders. If the system has just been booted it could be
+beneficial to run the function clear_holders.start_clear_holders_deps before
+using clear_holders.clear_holders. This ensures clear_holders will be able to
+properly storage devices. The function clear_holders.clear_holders can be
+passed either a single device or a list of devices and will shut down all
+storage devices above the device(s). The devices can be specified either by
+path in /dev or by path in /sys/class/block.
+
+In order to test if a device or devices are free to be partitioned/formatted,
+the function clear_holders.assert_clear can be passed either a single device or
+a list of devices, with devices specified either by path in /dev or by path in
+/sys/class/block. If there are any storage devices that depend on one of the
+devices passed to clear_holders.assert_clear, then an OSError will be raised.
+If clear_holders.assert_clear does not raise any errors, then the devices
+specified should be ready for partitioning.
+
+It is possible to query further information about storage devices using
+clear_holders.
+
+Holders for a individual device can be queried using clear_holders.get_holders.
+Results are returned as a list or knames for holding devices.
+
+A holders tree can be printed in a human readable format using
+clear_holders.format_holders_tree(). Example output:
+sda
+|-- sda1
+|-- sda2
+`-- sda5
+    `-- dm-0
+        |-- dm-1
+        `-- dm-2
+            `-- dm-3
 
=== modified file 'doc/index.rst'
--- doc/index.rst	2015-10-02 16:19:07 +0000
+++ doc/index.rst	2016-10-03 18:55:20 +0000
@@ -13,7 +13,13 @@
    :maxdepth: 2
 
    topics/overview
+   topics/config
+   topics/apt_source
+   topics/networking
+   topics/storage
    topics/reporting
+   topics/development
+   topics/integration-testing
 
 
 
 
=== added file 'doc/topics/apt_source.rst'
--- doc/topics/apt_source.rst	1970-01-01 00:00:00 +0000
+++ doc/topics/apt_source.rst	2016-10-03 18:55:20 +0000
@@ -0,0 +1,164 @@
+==========
+APT Source
+==========
+
+This part of curtin is meant to allow influencing the apt behaviour and configuration.
+
+By default - if no apt config is provided - it does nothing. That keeps behavior compatible on upgrades.
+
+The feature has an optional target argument which - by default - is used to modify the environment that curtin currently installs (@TARGET_MOUNT_POINT).
+
+Features
+~~~~~~~~
+
+* Add PGP keys to the APT trusted keyring
+
+  - add via short keyid
+
+  - add via long key fingerprint
+
+  - specify a custom keyserver to pull from
+
+  - add raw keys (which makes you independent of keyservers)
+
+* Influence global apt configuration
+
+  - adding ppa's
+
+  - replacing mirror, security mirror and release in sources.list
+
+  - able to provide a fully custom template for sources.list
+
+  - add arbitrary apt.conf settings
+
+  - provide debconf configurations
+
+  - disabling suites (=pockets)
+
+  - per architecture mirror definition
+
+
+Configuration
+~~~~~~~~~~~~~
+
+The general configuration of the apt feature is under an element called ``apt``.
+
+This can have various "global" subelements as listed in the examples below.
+The file ``apt-source.yaml`` holds more examples.
+
+These global configurations are valid throughput all of the apt feature.
+So for exmaple a global specification of a ``primary`` mirror will apply to all rendered sources entries.
+
+Then there is a section ``sources`` which can hold any number of source subelements itself.
+The key is the filename and will be prepended by /etc/apt/sources.list.d/ if it doesn't start with a ``/``.
+There are certain cases - where no content is written into a source.list file where the filename will be ignored - yet it can still be used as index for merging.
+
+The values inside the entries consist of the following optional entries
+
+* ``source``: a sources.list entry (some variable replacements apply)
+
+* ``keyid``: providing a key to import via shortid or fingerprint
+
+* ``key``: providing a raw PGP key
+
+* ``keyserver``: specify an alternate keyserver to pull keys from that were specified by keyid
+
+The section "sources" is is a dictionary (unlike most block/net configs which are lists). This format allows merging between multiple input files than a list like ::
+
+  sources:
+     s1: {'key': 'key1', 'source': 'source1'}
+
+  sources:
+     s2: {'key': 'key2'}
+     s1: {'keyserver': 'foo'}
+
+  This would be merged into
+     s1: {'key': 'key1', 'source': 'source1', keyserver: 'foo'}
+     s2: {'key': 'key2'}
+
+Here is just one of the most common examples for this feature: install with curtin in an isolated environment (derived repository):
+
+For that we need to:
+* insert the PGP key of the local repository to be trusted
+
+  - since you are locked down you can't pull from keyserver.ubuntu.com
+
+  - if you have an internal keyserver you could pull from there, but let us assume you don't even have that; so you have to provide the raw key
+
+  - in the example I'll use the key of the "Ubuntu CD Image Automatic Signing Key" which makes no sense as it is in the trusted keyring anyway, but it is a good example. (Also the key is shortened to stay readable)
+
+::
+
+      -----BEGIN PGP PUBLIC KEY BLOCK-----
+      Version: GnuPG v1
+      mQGiBEFEnz8RBAC7LstGsKD7McXZgd58oN68KquARLBl6rjA2vdhwl77KkPPOr3O
+      RwIbDAAKCRBAl26vQ30FtdxYAJsFjU+xbex7gevyGQ2/mhqidES4MwCggqQyo+w1
+      Twx6DKLF+3rF5nf1F3Q=
+      =PBAe
+      -----END PGP PUBLIC KEY BLOCK-----
+
+* replace the mirrors used to some mirrors available inside the isolated environment for apt to pull repository data from.
+
+  - lets consider we have a local mirror at ``mymirror.local`` but otherwise following the usual paths
+
+  - make an example with a partial mirror that doesn't mirror the backports suite, so backports have to be disabled
+
+That would be specified as ::
+
+  apt:
+    primary:
+      - arches [default]
+        uri: http://mymirror.local/ubuntu/
+    disable_suites: [backports]
+    sources:
+      localrepokey:
+        key: | # full key as block
+          -----BEGIN PGP PUBLIC KEY BLOCK-----
+          Version: GnuPG v1
+
+          mQGiBEFEnz8RBAC7LstGsKD7McXZgd58oN68KquARLBl6rjA2vdhwl77KkPPOr3O
+          RwIbDAAKCRBAl26vQ30FtdxYAJsFjU+xbex7gevyGQ2/mhqidES4MwCggqQyo+w1
+          Twx6DKLF+3rF5nf1F3Q=
+          =PBAe
+          -----END PGP PUBLIC KEY BLOCK-----
+
+The file examples/apt-source.yaml holds various further examples that can be configured with this feature.
+
+
+Common snippets
+~~~~~~~~~~~~~~~
+This is a collection of additional ideas people can use the feature for customizing their to-be-installed system.
+
+* enable proposed on installing
+
+::
+
+ apt:
+   sources:
+     proposed.list: deb $MIRROR $RELEASE-proposed main restricted universe multiverse
+
+* Make debug symbols available
+
+::
+
+ apt:
+   sources:
+     ddebs.list: |
+       deb http://ddebs.ubuntu.com $RELEASE main restricted universe multiverse
+       deb http://ddebs.ubuntu.com $RELEASE-updates main restricted universe multiverse
+       deb http://ddebs.ubuntu.com $RELEASE-security main restricted universe multiverse
+       deb http://ddebs.ubuntu.com $RELEASE-proposed main restricted universe multiverse
+
+Timing
+~~~~~~
+The feature is implemented at the stage of curthooks_commands, which runs just after curtin has extracted the image to the target.
+Additionally it can be ran as standalong command "curtin -v --config <yourconfigfile> apt-config".
+
+This will pick up the target from the environment variable that is set by curtin, if you want to use it to a different target or outside of usual curtin handling you can add ``--target <path>`` to it to overwrite the target path.
+This target should have at least a minimal system with apt, apt-add-repository and dpkg being installed for the functionality to work.
+
+
+Dependencies
+~~~~~~~~~~~~
+Cloud-init might need to resolve dependencies and install packages in the ephemeral environment to run curtin.
+Therefore it is recommended to not only provide an apt configuration to curtin for the target, but also one to the install environment via cloud-init.
 
=== added file 'doc/topics/config.rst'
--- doc/topics/config.rst	1970-01-01 00:00:00 +0000
+++ doc/topics/config.rst	2016-10-03 18:55:20 +0000
@@ -0,0 +1,551 @@
+====================
+Curtin Configuration
+====================
+
+Curtin exposes a number of configuration options for controlling Curtin
+behavior during installation.
+
+
+Configuration options
+---------------------
+Curtin's top level config keys are as follows:
+
+
+- apt_mirrors (``apt_mirrors``)
+- apt_proxy (``apt_proxy``)
+- block-meta (``block``)
+- debconf_selections (``debconf_selections``)
+- disable_overlayroot (``disable_overlayroot``)
+- grub (``grub``)
+- http_proxy (``http_proxy``)
+- install (``install``)
+- kernel (``kernel``)
+- kexec (``kexec``)
+- multipath (``multipath``)
+- network (``network``)
+- power_state (``power_state``)
+- reporting (``reporting``)
+- restore_dist_interfaces: (``restore_dist_interfaces``)
+- sources (``sources``)
+- stages (``stages``)
+- storage (``storage``)
+- swap (``swap``)
+- system_upgrade (``system_upgrade``)
+- write_files (``write_files``)
+
+
+apt_mirrors
+~~~~~~~~~~~
+Configure APT mirrors for ``ubuntu_archive`` and ``ubuntu_security``
+
+**ubuntu_archive**: *<http://local.archive/ubuntu>*
+
+**ubuntu_security**: *<http://local.archive/ubuntu>*
+
+If the target OS includes /etc/apt/sources.list, Curtin will replace
+the default values for each key set with the supplied mirror URL.
+
+**Example**::
+
+  apt_mirrors:
+    ubuntu_archive: http://local.archive/ubuntu
+    ubuntu_security: http://local.archive/ubuntu
+
+
+apt_proxy
+~~~~~~~~~
+Curtin will configure an APT HTTP proxy in the target OS
+
+**apt_proxy**: *<URL to APT proxy>*
+
+**Example**::
+
+  apt_proxy: http://squid.mirror:3267/
+
+
+block-meta
+~~~~~~~~~~
+Configure how Curtin selects and configures disks on the target
+system without providing a custom configuration (mode=simple).
+
+**devices**: *<List of block devices for use>*
+
+The ``devices`` parameter is a list of block device paths that Curtin may
+select from with choosing where to install the OS.
+
+**boot-partition**: *<dictionary of configuration>*
+
+The ``boot-partition`` parameter controls how to configure the boot partition
+with the following parameters:
+
+**enabled**: *<boolean>*
+
+Enabled will forcibly setup a partition on the target device for booting.
+
+**format**: *<['uefi', 'gpt', 'prep', 'mbr']>*
+
+Specify the partition format.  Some formats, like ``uefi`` and ``prep``
+are restricted by platform characteristics.
+
+**fstype**: *<filesystem type: one of ['ext3', 'ext4'], defaults to 'ext4'>*
+
+Specify the filesystem format on the boot partition.
+
+**label**: *<filesystem label: defaults to 'boot'>*
+
+Specify the filesystem label on the boot partition.
+
+**Example**::
+
+  block-meta:
+      devices:
+        - /dev/sda
+        - /dev/sdb
+      boot-partition:
+        - enabled: True
+          format: gpt
+          fstype: ext4
+          label: my-boot-partition
+
+
+debconf_selections
+~~~~~~~~~~~~~~~~~~
+Curtin will update the target with debconf set-selection values.  Users will
+need to be familiar with the package debconf options.  Users can probe a
+packages' debconf settings by using ``debconf-get-selections``.
+
+**selection_name**: *<debconf-set-selections input>*
+
+``debconf-set-selections`` is in the form::
+
+  <packagename> <packagename/option-name> <type> <value>
+
+**Example**::
+
+  debconf_selections:
+    set1: |
+      cloud-init cloud-init/datasources multiselect MAAS
+      lxd lxd/bridge-name string lxdbr0
+    set2: lxd lxd/setup-bridge boolean true
+
+
+
+disable_overlayroot
+~~~~~~~~~~~~~~~~~~~
+Curtin disables overlayroot in the target by default.
+
+**disable_overlayroot**: *<boolean: default True>*
+
+**Example**::
+
+  disable_overlayroot: False
+
+
+grub
+~~~~
+Curtin configures grub as the target machine's boot loader.  Users
+can control a few options to tailor how the system will boot after
+installation.
+
+**install_devices**: *<list of block device names to install grub>*
+
+Specify a list of devices onto which grub will attempt to install.
+
+**replace_linux_default**: *<boolean: default True>*
+
+Controls whether grub-install will update the Linux Default target
+value during installation.
+
+**update_nvram**: *<boolean: default False>*
+
+Certain platforms, like ``uefi`` and ``prep`` systems utilize
+NVRAM to hold boot configuration settings which control the order in
+which devices are booted.  Curtin by default will not attempt to
+update the NVRAM settings to preserve the system configuration.
+Users may want to force NVRAM to be updated such that the next boot
+of the system will boot from the installed device.
+
+**Example**::
+
+  grub:
+     install_devices:
+       - /dev/sda1
+     replace_linux_default: False
+     update_nvram: True
+
+
+http_proxy
+~~~~~~~~~~
+Curtin will export ``http_proxy`` value into the installer environment.
+
+**http_proxy**: *<HTTP Proxy URL>*
+
+**Example**::
+
+  http_proxy: http://squid.proxy:3728/
+
+
+
+install
+~~~~~~~
+Configure Curtin's install options.
+
+**log_file**: *<path to write Curtin's install.log data>*
+
+Curtin logs install progress by default to /var/log/curtin/install.log
+
+**post_files**: *<List of files to read from host to include in reporting data>*
+
+Curtin by default will post the ``log_file`` value to any configured reporter.
+
+**save_install_config**: *<Path to save merged curtin configuration file>*
+
+Curtin will save the merged configuration data into the target OS at 
+the path of ``save_install_config``.  This defaults to /root/curtin-install-cfg.yaml
+
+**Example**::
+
+  install:
+     log_file: /tmp/install.log
+     post_files:
+       - /tmp/install.log
+       - /var/log/syslog
+     save_install_config: /root/myconf.yaml
+
+
+kernel
+~~~~~~
+Configure how Curtin selects which kernel to install into the target image.
+If ``kernel`` is not configured, Curtin will use the default mapping below
+and determine which ``package`` value by looking up the current release
+and current kernel version running.
+
+
+**fallback-package**: *<kernel package-name to be used as fallback>*
+
+Specify a kernel package name to be used if the default package is not
+available.
+
+**mapping**: *<Dictionary mapping Ubuntu release to HWE kernel names>*
+
+Default mapping for Releases to package names is as follows::
+
+ precise:
+    3.2.0: 
+    3.5.0: -lts-quantal
+    3.8.0: -lts-raring
+    3.11.0: -lts-saucy
+    3.13.0: -lts-trusty
+  trusty:
+    3.13.0: 
+    3.16.0: -lts-utopic
+    3.19.0: -lts-vivid
+    4.2.0: -lts-wily
+    4.4.0: -lts-xenial
+  xenial:
+    4.3.0:
+    4.4.0:
+ 
+
+**package**: *<Linux kernel package name>*
+
+Specify the exact package to install in the target OS.
+
+**Example**::
+
+  kernel:
+    fallback-package: linux-image-generic
+    package: linux-image-generic-lts-xenial
+    mapping:
+      - xenial:
+        - 4.4.0: -my-custom-kernel    
+
+
+kexec
+~~~~~
+Curtin can use kexec to "reboot" into the target OS.
+
+**mode**: *<on>*
+
+Enable rebooting with kexec.
+
+**Example**::
+
+  kexec: on
+
+
+multipath
+~~~~~~~~~
+Curtin will detect and autoconfigure multipath by default to enable
+boot for systems with multipath.  Curtin does not apply any advanced
+configuration or tuning, rather it uses distro defaults and provides
+enough configuration to enable booting.
+
+**mode**: *<['auto', ['disabled']>*
+
+Defaults to auto which will configure enough to enable booting on multipath
+devices.  Disabled will prevent curtin from installing or configuring
+multipath.
+
+**overwrite_bindings**: *<boolean>*
+
+If ``overwrite_bindings`` is True then Curtin will generate new bindings
+file for multipath, overriding any existing binding in the target image.
+
+**Example**::
+
+  multipath:
+      mode: auto
+      overwrite_bindings: True
+
+
+network
+~~~~~~~
+Configure networking (see Networking section for details).
+
+**network_option_1**: *<option value>*
+