Merge lp:~tribaal/charms/precise/storage/add-ceph-storage-provider into lp:charms/storage

[Chris Glass]

This branch adds basic support for a "ceph" storage provider that mounts and uses a ceph image to use as storage.

It is currently rough (not working 100%), but I'd like to have eyes on the code before I go any further with it (I don't understand exactly what's wrong with my approach).

[Chad Smith (chad.smith)]

Chris, just on first glance it seems you are missing the ceph-relation-changed hook symlink in the hooks directory. Those hooks are needed as links to hooks/hooks as it is a proxy for calls to the underlying storage-provider.d/<provider_name>/your-hook-name. If the hook symlink doesn't exist at hooks/ceph-relation-changed you should see a "no ceph-relation-changed hook" message in the juju logs.

I'll peek more at this on with a live deployment.

[lp:~tribaal/charms/precise/storage/add-ceph-storage-provider]

44. By Chris Glass on 2014-08-27

Added ceph-relation-changed hook symlink.

45. By Chris Glass on 2014-08-27

Make the ceph-relation-changed hook noop if all the necessary information is
not present (like the key).

46. By Chris Glass on 2014-08-27

added relation debug output

[David Britton (dpb)]

Hi Chris -- Thanks so much for doing this!

The general approach looks great. Can you implement the data-relation-departed hook as well? I noticed an 'unmount' commented out import in the data-relation-changed hook as well, thought maybe you were thinking about doing that when you stopped for a quick sanity-check.

Before I run through paces, I wanted to make sure that you include a sample deployment when working with ceph at least here in the review so we can compare apples to apples.

Also I added a simple nit for a diff comment.

This change is quite exciting, glad so much of it is contained in charmhelpers. :)

review: Needs Information

[Chris Glass (tribaal)]

Yes, I started working on the unmount logic, but then realised this branch was already 2k lines, so I decided against putting even more code in.

I'll add it in here, no problem.

[lp:~tribaal/charms/precise/storage/add-ceph-storage-provider]

47. By Chris Glass on 2014-09-09

Added exit(0)!

Unmerged revisions

47. By Chris Glass on 2014-09-09

Added exit(0)!

46. By Chris Glass on 2014-08-27

added relation debug output

45. By Chris Glass on 2014-08-27

Make the ceph-relation-changed hook noop if all the necessary information is
not present (like the key).

44. By Chris Glass on 2014-08-27

Added ceph-relation-changed hook symlink.

43. By Chris Glass on 2014-08-26

Added some debug logs...

42. By Chris Glass on 2014-08-26

Added logs to the data-relation-changed hook

41. By Chris Glass on 2014-08-21

Put the common ceph code in a proper python module.

40. By Chris Glass on 2014-08-21

Made hook executable. Duh.

39. By Chris Glass on 2014-08-21

Update charm-helpers along with the make file to sync them.

38. By Chris Glass on 2014-08-21

The hooks should work

=== modified file '.bzrignore'
--- .bzrignore	2014-01-31 23:49:37 +0000
+++ .bzrignore	2014-09-09 05:13:17 +0000
@@ -1,2 +1,3 @@
 _trial_temp
 charm-helpers
+bin/
 
=== modified file 'Makefile'
--- Makefile	2014-02-10 22:52:50 +0000
+++ Makefile	2014-09-09 05:13:17 +0000
@@ -1,4 +1,6 @@
+#!/usr/bin/make
 .PHONY: test lint clean
+PYTHON := /usr/bin/env python
 
 clean:
 	find . -name *.pyc | xargs rm
@@ -11,12 +13,10 @@
 	# flake any python scripts not named *.py
 	fgrep -r bin/python hooks/ | awk -F :  '{print $$1}' | xargs -r -n1 flake8
 
-
-update-charm-helpers:
-	# Pull latest charm-helpers branch and sync the components based on our
-	$ charm-helpers.yaml
-	rm -rf charm-helpers
-	bzr co lp:charm-helpers
-	./charm-helpers/tools/charm_helpers_sync/charm_helpers_sync.py -c charm-helpers.yaml
-	rm -rf charm-helpers
-
+bin/charm_helpers_sync.py:
+	@mkdir -p bin
+	@bzr cat lp:charm-helpers/tools/charm_helpers_sync/charm_helpers_sync.py \
+	> bin/charm_helpers_sync.py
+
+sync: bin/charm_helpers_sync.py
+	@$(PYTHON) bin/charm_helpers_sync.py -c charm-helpers.yaml
 
=== modified file 'charm-helpers.yaml'
--- charm-helpers.yaml	2014-01-31 23:49:37 +0000
+++ charm-helpers.yaml	2014-09-09 05:13:17 +0000
@@ -3,3 +3,4 @@
 include:
     - core
     - fetch
+    - contrib.storage.linux.ceph
 
=== added symlink 'hooks/ceph-relation-changed'
=== target is u'hooks'
=== added file 'hooks/ceph_common.py'
--- hooks/ceph_common.py	1970-01-01 00:00:00 +0000
+++ hooks/ceph_common.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,12 @@
+
+from charmhelpers.core.hookenv import (
+    service_name,
+)
+
+SERVICE_NAME = service_name()  # TODO: Make sure it's the unit - not "storage"
+TEMPORARY_MOUNT_POINT = "/mnt/temp-ceph/%s" % SERVICE_NAME
+POOL_NAME = SERVICE_NAME
+
+
+RDB_IMG = "storage"
+BLK_DEVICE = '/dev/rbd/%s/%s' % (POOL_NAME, RDB_IMG)
 
=== added directory 'hooks/charmhelpers/contrib'
=== added file 'hooks/charmhelpers/contrib/__init__.py'
=== added directory 'hooks/charmhelpers/contrib/storage'
=== added file 'hooks/charmhelpers/contrib/storage/__init__.py'
=== added directory 'hooks/charmhelpers/contrib/storage/linux'
=== added file 'hooks/charmhelpers/contrib/storage/linux/__init__.py'
=== added file 'hooks/charmhelpers/contrib/storage/linux/ceph.py'
--- hooks/charmhelpers/contrib/storage/linux/ceph.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/storage/linux/ceph.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,387 @@
+#
+# Copyright 2012 Canonical Ltd.
+#
+# This file is sourced from lp:openstack-charm-helpers
+#
+# Authors:
+#  James Page <[e-mail]>
+#  Adam Gandelman <[e-mail]>
+#
+
+import os
+import shutil
+import json
+import time
+
+from subprocess import (
+    check_call,
+    check_output,
+    CalledProcessError
+)
+
+from charmhelpers.core.hookenv import (
+    relation_get,
+    relation_ids,
+    related_units,
+    log,
+    INFO,
+    WARNING,
+    ERROR
+)
+
+from charmhelpers.core.host import (
+    mount,
+    mounts,
+    service_start,
+    service_stop,
+    service_running,
+    umount,
+)
+
+from charmhelpers.fetch import (
+    apt_install,
+)
+
+KEYRING = '/etc/ceph/ceph.client.{}.keyring'
+KEYFILE = '/etc/ceph/ceph.client.{}.key'
+
+CEPH_CONF = """[global]
+ auth supported = {auth}
+ keyring = {keyring}
+ mon host = {mon_hosts}
+ log to syslog = {use_syslog}
+ err to syslog = {use_syslog}
+ clog to syslog = {use_syslog}
+"""
+
+
+def install():
+    ''' Basic Ceph client installation '''
+    ceph_dir = "/etc/ceph"
+    if not os.path.exists(ceph_dir):
+        os.mkdir(ceph_dir)
+    apt_install('ceph-common', fatal=True)
+
+
+def rbd_exists(service, pool, rbd_img):
+    ''' Check to see if a RADOS block device exists '''
+    try:
+        out = check_output(['rbd', 'list', '--id', service,
+                            '--pool', pool])
+    except CalledProcessError:
+        return False
+    else:
+        return rbd_img in out
+
+
+def create_rbd_image(service, pool, image, sizemb):
+    ''' Create a new RADOS block device '''
+    cmd = [
+        'rbd',
+        'create',
+        image,
+        '--size',
+        str(sizemb),
+        '--id',
+        service,
+        '--pool',
+        pool
+    ]
+    check_call(cmd)
+
+
+def pool_exists(service, name):
+    ''' Check to see if a RADOS pool already exists '''
+    try:
+        out = check_output(['rados', '--id', service, 'lspools'])
+    except CalledProcessError:
+        return False
+    else:
+        return name in out
+
+
+def get_osds(service):
+    '''
+    Return a list of all Ceph Object Storage Daemons
+    currently in the cluster
+    '''
+    version = ceph_version()
+    if version and version >= '0.56':
+        return json.loads(check_output(['ceph', '--id', service,
+                                        'osd', 'ls', '--format=json']))
+    else:
+        return None
+
+
+def create_pool(service, name, replicas=2):
+    ''' Create a new RADOS pool '''
+    if pool_exists(service, name):
+        log("Ceph pool {} already exists, skipping creation".format(name),
+            level=WARNING)
+        return
+    # Calculate the number of placement groups based
+    # on upstream recommended best practices.
+    osds = get_osds(service)
+    if osds:
+        pgnum = (len(osds) * 100 / replicas)
+    else:
+        # NOTE(james-page): Default to 200 for older ceph versions
+        # which don't support OSD query from cli
+        pgnum = 200
+    cmd = [
+        'ceph', '--id', service,
+        'osd', 'pool', 'create',
+        name, str(pgnum)
+    ]
+    check_call(cmd)
+    cmd = [
+        'ceph', '--id', service,
+        'osd', 'pool', 'set', name,
+        'size', str(replicas)
+    ]
+    check_call(cmd)
+
+
+def delete_pool(service, name):
+    ''' Delete a RADOS pool from ceph '''
+    cmd = [
+        'ceph', '--id', service,
+        'osd', 'pool', 'delete',
+        name, '--yes-i-really-really-mean-it'
+    ]
+    check_call(cmd)
+
+
+def _keyfile_path(service):
+    return KEYFILE.format(service)
+
+
+def _keyring_path(service):
+    return KEYRING.format(service)
+
+
+def create_keyring(service, key):
+    ''' Create a new Ceph keyring containing key'''
+    keyring = _keyring_path(service)
+    if os.path.exists(keyring):
+        log('ceph: Keyring exists at %s.' % keyring, level=WARNING)
+        return
+    cmd = [
+        'ceph-authtool',
+        keyring,
+        '--create-keyring',
+        '--name=client.{}'.format(service),
+        '--add-key={}'.format(key)
+    ]
+    check_call(cmd)
+    log('ceph: Created new ring at %s.' % keyring, level=INFO)
+
+
+def create_key_file(service, key):
+    ''' Create a file containing key '''
+    keyfile = _keyfile_path(service)
+    if os.path.exists(keyfile):
+        log('ceph: Keyfile exists at %s.' % keyfile, level=WARNING)
+        return
+    with open(keyfile, 'w') as fd:
+        fd.write(key)
+    log('ceph: Created new keyfile at %s.' % keyfile, level=INFO)
+
+
+def get_ceph_nodes():
+    ''' Query named relation 'ceph' to detemine current nodes '''
+    hosts = []
+    for r_id in relation_ids('ceph'):
+        for unit in related_units(r_id):
+            hosts.append(relation_get('private-address', unit=unit, rid=r_id))
+    return hosts
+
+
+def configure(service, key, auth, use_syslog):
+    ''' Perform basic configuration of Ceph '''
+    create_keyring(service, key)
+    create_key_file(service, key)
+    hosts = get_ceph_nodes()
+    with open('/etc/ceph/ceph.conf', 'w') as ceph_conf:
+        ceph_conf.write(CEPH_CONF.format(auth=auth,
+                                         keyring=_keyring_path(service),
+                                         mon_hosts=",".join(map(str, hosts)),
+                                         use_syslog=use_syslog))
+    modprobe('rbd')
+
+
+def image_mapped(name):
+    ''' Determine whether a RADOS block device is mapped locally '''
+    try:
+        out = check_output(['rbd', 'showmapped'])
+    except CalledProcessError:
+        return False
+    else:
+        return name in out
+
+
+def map_block_storage(service, pool, image):
+    ''' Map a RADOS block device for local use '''
+    cmd = [
+        'rbd',
+        'map',
+        '{}/{}'.format(pool, image),
+        '--user',
+        service,
+        '--secret',
+        _keyfile_path(service),
+    ]
+    check_call(cmd)
+
+
+def filesystem_mounted(fs):
+    ''' Determine whether a filesytems is already mounted '''
+    return fs in [f for f, m in mounts()]
+
+
+def make_filesystem(blk_device, fstype='ext4', timeout=10):
+    ''' Make a new filesystem on the specified block device '''
+    count = 0
+    e_noent = os.errno.ENOENT
+    while not os.path.exists(blk_device):
+        if count >= timeout:
+            log('ceph: gave up waiting on block device %s' % blk_device,
+                level=ERROR)
+            raise IOError(e_noent, os.strerror(e_noent), blk_device)
+        log('ceph: waiting for block device %s to appear' % blk_device,
+            level=INFO)
+        count += 1
+        time.sleep(1)
+    else:
+        log('ceph: Formatting block device %s as filesystem %s.' %
+            (blk_device, fstype), level=INFO)
+        check_call(['mkfs', '-t', fstype, blk_device])
+
+
+def place_data_on_block_device(blk_device, data_src_dst):
+    ''' Migrate data in data_src_dst to blk_device and then remount '''
+    # mount block device into /mnt
+    mount(blk_device, '/mnt')
+    # copy data to /mnt
+    copy_files(data_src_dst, '/mnt')
+    # umount block device
+    umount('/mnt')
+    # Grab user/group ID's from original source
+    _dir = os.stat(data_src_dst)
+    uid = _dir.st_uid
+    gid = _dir.st_gid
+    # re-mount where the data should originally be
+    # TODO: persist is currently a NO-OP in core.host
+    mount(blk_device, data_src_dst, persist=True)
+    # ensure original ownership of new mount.
+    os.chown(data_src_dst, uid, gid)
+
+
+# TODO: re-use
+def modprobe(module):
+    ''' Load a kernel module and configure for auto-load on reboot '''
+    log('ceph: Loading kernel module', level=INFO)
+    cmd = ['modprobe', module]
+    check_call(cmd)
+    with open('/etc/modules', 'r+') as modules:
+        if module not in modules.read():
+            modules.write(module)
+
+
+def copy_files(src, dst, symlinks=False, ignore=None):
+    ''' Copy files from src to dst '''
+    for item in os.listdir(src):
+        s = os.path.join(src, item)
+        d = os.path.join(dst, item)
+        if os.path.isdir(s):
+            shutil.copytree(s, d, symlinks, ignore)
+        else:
+            shutil.copy2(s, d)
+
+
+def ensure_ceph_storage(service, pool, rbd_img, sizemb, mount_point,
+                        blk_device, fstype, system_services=[]):
+    """
+    NOTE: This function must only be called from a single service unit for
+    the same rbd_img otherwise data loss will occur.
+
+    Ensures given pool and RBD image exists, is mapped to a block device,
+    and the device is formatted and mounted at the given mount_point.
+
+    If formatting a device for the first time, data existing at mount_point
+    will be migrated to the RBD device before being re-mounted.
+
+    All services listed in system_services will be stopped prior to data
+    migration and restarted when complete.
+    """
+    # Ensure pool, RBD image, RBD mappings are in place.
+    if not pool_exists(service, pool):
+        log('ceph: Creating new pool {}.'.format(pool))
+        create_pool(service, pool)
+
+    if not rbd_exists(service, pool, rbd_img):
+        log('ceph: Creating RBD image ({}).'.format(rbd_img))
+        create_rbd_image(service, pool, rbd_img, sizemb)
+
+    if not image_mapped(rbd_img):
+        log('ceph: Mapping RBD Image {} as a Block Device.'.format(rbd_img))
+        map_block_storage(service, pool, rbd_img)
+
+    # make file system
+    # TODO: What happens if for whatever reason this is run again and
+    # the data is already in the rbd device and/or is mounted??
+    # When it is mounted already, it will fail to make the fs
+    # XXX: This is really sketchy!  Need to at least add an fstab entry
+    #      otherwise this hook will blow away existing data if its executed
+    #      after a reboot.
+    if not filesystem_mounted(mount_point):
+        make_filesystem(blk_device, fstype)
+
+        for svc in system_services:
+            if service_running(svc):
+                log('ceph: Stopping services {} prior to migrating data.'
+                    .format(svc))
+                service_stop(svc)
+
+        place_data_on_block_device(blk_device, mount_point)
+
+        for svc in system_services:
+            log('ceph: Starting service {} after migrating data.'
+                .format(svc))
+            service_start(svc)
+
+
+def ensure_ceph_keyring(service, user=None, group=None):
+    '''
+    Ensures a ceph keyring is created for a named service
+    and optionally ensures user and group ownership.
+
+    Returns False if no ceph key is available in relation state.
+    '''
+    key = None
+    for rid in relation_ids('ceph'):
+        for unit in related_units(rid):
+            key = relation_get('key', rid=rid, unit=unit)
+            if key:
+                break
+    if not key:
+        return False
+    create_keyring(service=service, key=key)
+    keyring = _keyring_path(service)
+    if user and group:
+        check_call(['chown', '%s.%s' % (user, group), keyring])
+    return True
+
+
+def ceph_version():
+    ''' Retrieve the local version of ceph '''
+    if os.path.exists('/usr/bin/ceph'):
+        cmd = ['ceph', '-v']
+        output = check_output(cmd)
+        output = output.split()
+        if len(output) > 3:
+            return output[2]
+        else:
+            return None
+    else:
+        return None
 
=== added file 'hooks/charmhelpers/core/fstab.py'
--- hooks/charmhelpers/core/fstab.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/fstab.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,116 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+__author__ = 'Jorge Niedbalski R. <[e-mail]>'
+
+import os
+
+
+class Fstab(file):
+    """This class extends file in order to implement a file reader/writer
+    for file `/etc/fstab`
+    """
+
+    class Entry(object):
+        """Entry class represents a non-comment line on the `/etc/fstab` file
+        """
+        def __init__(self, device, mountpoint, filesystem,
+                     options, d=0, p=0):
+            self.device = device
+            self.mountpoint = mountpoint
+            self.filesystem = filesystem
+
+            if not options:
+                options = "defaults"
+
+            self.options = options
+            self.d = d
+            self.p = p
+
+        def __eq__(self, o):
+            return str(self) == str(o)
+
+        def __str__(self):
+            return "{} {} {} {} {} {}".format(self.device,
+                                              self.mountpoint,
+                                              self.filesystem,
+                                              self.options,
+                                              self.d,
+                                              self.p)
+
+    DEFAULT_PATH = os.path.join(os.path.sep, 'etc', 'fstab')
+
+    def __init__(self, path=None):
+        if path:
+            self._path = path
+        else:
+            self._path = self.DEFAULT_PATH
+        file.__init__(self, self._path, 'r+')
+
+    def _hydrate_entry(self, line):
+        # NOTE: use split with no arguments to split on any
+        #       whitespace including tabs
+        return Fstab.Entry(*filter(
+            lambda x: x not in ('', None),
+            line.strip("\n").split()))
+
+    @property
+    def entries(self):
+        self.seek(0)
+        for line in self.readlines():
+            try:
+                if not line.startswith("#"):
+                    yield self._hydrate_entry(line)
+            except ValueError:
+                pass
+
+    def get_entry_by_attr(self, attr, value):
+        for entry in self.entries:
+            e_attr = getattr(entry, attr)
+            if e_attr == value:
+                return entry
+        return None
+
+    def add_entry(self, entry):
+        if self.get_entry_by_attr('device', entry.device):
+            return False
+
+        self.write(str(entry) + '\n')
+        self.truncate()
+        return entry
+
+    def remove_entry(self, entry):
+        self.seek(0)
+
+        lines = self.readlines()
+
+        found = False
+        for index, line in enumerate(lines):
+            if not line.startswith("#"):
+                if self._hydrate_entry(line) == entry:
+                    found = True
+                    break
+
+        if not found:
+            return False
+
+        lines.remove(line)
+
+        self.seek(0)
+        self.write(''.join(lines))
+        self.truncate()
+        return True
+
+    @classmethod
+    def remove_by_mountpoint(cls, mountpoint, path=None):
+        fstab = cls(path=path)
+        entry = fstab.get_entry_by_attr('mountpoint', mountpoint)
+        if entry:
+            return fstab.remove_entry(entry)
+        return False
+
+    @classmethod
+    def add(cls, device, mountpoint, filesystem, options=None, path=None):
+        return cls(path=path).add_entry(Fstab.Entry(device,
+                                                    mountpoint, filesystem,
+                                                    options=options))
 
=== modified file 'hooks/charmhelpers/core/hookenv.py'
--- hooks/charmhelpers/core/hookenv.py	2014-01-14 21:55:40 +0000
+++ hooks/charmhelpers/core/hookenv.py	2014-09-09 05:13:17 +0000
@@ -8,6 +8,7 @@
 import json
 import yaml
 import subprocess
+import sys
 import UserDict
 from subprocess import CalledProcessError
 
@@ -24,7 +25,7 @@
 def cached(func):
     """Cache return values for multiple executions of func + args
 
-    For example:
+    For example::
 
         @cached
         def unit_get(attribute):
@@ -149,6 +150,105 @@
     return local_unit().split('/')[0]
 
 
+def hook_name():
+    """The name of the currently executing hook"""
+    return os.path.basename(sys.argv[0])
+
+
+class Config(dict):
+    """A Juju charm config dictionary that can write itself to
+    disk (as json) and track which values have changed since
+    the previous hook invocation.
+
+    Do not instantiate this object directly - instead call
+    ``hookenv.config()``
+
+    Example usage::
+
+        >>> # inside a hook
+        >>> from charmhelpers.core import hookenv
+        >>> config = hookenv.config()
+        >>> config['foo']
+        'bar'
+        >>> config['mykey'] = 'myval'
+        >>> config.save()
+
+
+        >>> # user runs `juju set mycharm foo=baz`
+        >>> # now we're inside subsequent config-changed hook
+        >>> config = hookenv.config()
+        >>> config['foo']
+        'baz'
+        >>> # test to see if this val has changed since last hook
+        >>> config.changed('foo')
+        True
+        >>> # what was the previous value?
+        >>> config.previous('foo')
+        'bar'
+        >>> # keys/values that we add are preserved across hooks
+        >>> config['mykey']
+        'myval'
+        >>> # don't forget to save at the end of hook!
+        >>> config.save()
+
+    """
+    CONFIG_FILE_NAME = '.juju-persistent-config'
+
+    def __init__(self, *args, **kw):
+        super(Config, self).__init__(*args, **kw)
+        self._prev_dict = None
+        self.path = os.path.join(charm_dir(), Config.CONFIG_FILE_NAME)
+        if os.path.exists(self.path):
+            self.load_previous()
+
+    def load_previous(self, path=None):
+        """Load previous copy of config from disk so that current values
+        can be compared to previous values.
+
+        :param path:
+
+            File path from which to load the previous config. If `None`,
+            config is loaded from the default location. If `path` is
+            specified, subsequent `save()` calls will write to the same
+            path.
+
+        """
+        self.path = path or self.path
+        with open(self.path) as f:
+            self._prev_dict = json.load(f)
+
+    def changed(self, key):
+        """Return true if the value for this key has changed since
+        the last save.
+
+        """
+        if self._prev_dict is None:
+            return True
+        return self.previous(key) != self.get(key)
+
+    def previous(self, key):
+        """Return previous value for this key, or None if there
+        is no "previous" value.
+
+        """
+        if self._prev_dict:
+            return self._prev_dict.get(key)
+        return None
+
+    def save(self):
+        """Save this config to disk.
+
+        Preserves items in _prev_dict that do not exist in self.
+
+        """
+        if self._prev_dict:
+            for k, v in self._prev_dict.iteritems():
+                if k not in self:
+                    self[k] = v
+        with open(self.path, 'w') as f:
+            json.dump(self, f)
+
+
 @cached
 def config(scope=None):
     """Juju charm configuration"""
@@ -157,7 +257,10 @@
         config_cmd_line.append(scope)
     config_cmd_line.append('--format=json')
     try:
-        return json.loads(subprocess.check_output(config_cmd_line))
+        config_data = json.loads(subprocess.check_output(config_cmd_line))
+        if scope is not None:
+            return config_data
+        return Config(config_data)
     except ValueError:
         return None
 
@@ -182,8 +285,9 @@
         raise
 
 
-def relation_set(relation_id=None, relation_settings={}, **kwargs):
+def relation_set(relation_id=None, relation_settings=None, **kwargs):
     """Set relation information for the current unit"""
+    relation_settings = relation_settings if relation_settings else {}
     relation_cmd_line = ['relation-set']
     if relation_id is not None:
         relation_cmd_line.extend(('-r', relation_id))
@@ -342,18 +446,19 @@
 class Hooks(object):
     """A convenient handler for hook functions.
 
-    Example:
+    Example::
+
         hooks = Hooks()
 
         # register a hook, taking its name from the function name
         @hooks.hook()
         def install():
-            ...
+            pass  # your code here
 
         # register a hook, providing a custom hook name
         @hooks.hook("config-changed")
         def config_changed():
-            ...
+            pass  # your code here
 
         if __name__ == "__main__":
             # execute a hook based on the name the program is called by
 
=== modified file 'hooks/charmhelpers/core/host.py'
--- hooks/charmhelpers/core/host.py	2014-01-14 21:55:40 +0000
+++ hooks/charmhelpers/core/host.py	2014-09-09 05:13:17 +0000
@@ -12,10 +12,13 @@
 import string
 import subprocess
 import hashlib
+import shutil
+from contextlib import contextmanager
 
 from collections import OrderedDict
 
 from hookenv import log
+from fstab import Fstab
 
 
 def service_start(service_name):
@@ -34,7 +37,8 @@
 
 
 def service_reload(service_name, restart_on_failure=False):
-    """Reload a system service, optionally falling back to restart if reload fails"""
+    """Reload a system service, optionally falling back to restart if
+    reload fails"""
     service_result = service('reload', service_name)
     if not service_result and restart_on_failure:
         service_result = service('restart', service_name)
@@ -50,7 +54,7 @@
 def service_running(service):
     """Determine whether a system service is running"""
     try:
-        output = subprocess.check_output(['service', service, 'status'])
+        output = subprocess.check_output(['service', service, 'status'], stderr=subprocess.STDOUT)
     except subprocess.CalledProcessError:
         return False
     else:
@@ -60,6 +64,16 @@
             return False
 
 
+def service_available(service_name):
+    """Determine whether a system service is available"""
+    try:
+        subprocess.check_output(['service', service_name, 'status'], stderr=subprocess.STDOUT)
+    except subprocess.CalledProcessError:
+        return False
+    else:
+        return True
+
+
 def adduser(username, password=None, shell='/bin/bash', system_user=False):
     """Add a user to the system"""
     try:
@@ -143,7 +157,19 @@
         target.write(content)
 
 
-def mount(device, mountpoint, options=None, persist=False):
+def fstab_remove(mp):
+    """Remove the given mountpoint entry from /etc/fstab
+    """
+    return Fstab.remove_by_mountpoint(mp)
+
+
+def fstab_add(dev, mp, fs, options=None):
+    """Adds the given device entry to the /etc/fstab file
+    """
+    return Fstab.add(dev, mp, fs, options=options)
+
+
+def mount(device, mountpoint, options=None, persist=False, filesystem="ext3"):
     """Mount a filesystem at a particular mountpoint"""
     cmd_args = ['mount']
     if options is not None:
@@ -154,9 +180,9 @@
     except subprocess.CalledProcessError, e:
         log('Error mounting {} at {}\n{}'.format(device, mountpoint, e.output))
         return False
+
     if persist:
-        # TODO: update fstab
-        pass
+        return fstab_add(device, mountpoint, filesystem, options=options)
     return True
 
 
@@ -168,9 +194,9 @@
     except subprocess.CalledProcessError, e:
         log('Error unmounting {}\n{}'.format(mountpoint, e.output))
         return False
+
     if persist:
-        # TODO: update fstab
-        pass
+        return fstab_remove(mountpoint)
     return True
 
 
@@ -194,16 +220,16 @@
         return None
 
 
-def restart_on_change(restart_map):
+def restart_on_change(restart_map, stopstart=False):
     """Restart services based on configuration files changing
 
-    This function is used a decorator, for example
+    This function is used a decorator, for example::
 
         @restart_on_change({
             '/etc/ceph/ceph.conf': [ 'cinder-api', 'cinder-volume' ]
             })
         def ceph_client_changed():
-            ...
+            pass  # your code here
 
     In this example, the cinder-api and cinder-volume services
     would be restarted if /etc/ceph/ceph.conf is changed by the
@@ -219,8 +245,14 @@
             for path in restart_map:
                 if checksums[path] != file_hash(path):
                     restarts += restart_map[path]
-            for service_name in list(OrderedDict.fromkeys(restarts)):
-                service('restart', service_name)
+            services_list = list(OrderedDict.fromkeys(restarts))
+            if not stopstart:
+                for service_name in services_list:
+                    service('restart', service_name)
+            else:
+                for action in ['stop', 'start']:
+                    for service_name in services_list:
+                        service(action, service_name)
         return wrapped_f
     return wrap
 
@@ -289,3 +321,44 @@
     if 'link/ether' in words:
         hwaddr = words[words.index('link/ether') + 1]
     return hwaddr
+
+
+def cmp_pkgrevno(package, revno, pkgcache=None):
+    '''Compare supplied revno with the revno of the installed package
+
+    *  1 => Installed revno is greater than supplied arg
+    *  0 => Installed revno is the same as supplied arg
+    * -1 => Installed revno is less than supplied arg
+
+    '''
+    import apt_pkg
+    if not pkgcache:
+        apt_pkg.init()
+        # Force Apt to build its cache in memory. That way we avoid race
+        # conditions with other applications building the cache in the same
+        # place.
+        apt_pkg.config.set("Dir::Cache::pkgcache", "")
+        pkgcache = apt_pkg.Cache()
+    pkg = pkgcache[package]
+    return apt_pkg.version_compare(pkg.current_ver.ver_str, revno)
+
+
+@contextmanager
+def chdir(d):
+    cur = os.getcwd()
+    try:
+        yield os.chdir(d)
+    finally:
+        os.chdir(cur)
+
+
+def chownr(path, owner, group):
+    uid = pwd.getpwnam(owner).pw_uid
+    gid = grp.getgrnam(group).gr_gid
+
+    for root, dirs, files in os.walk(path):
+        for name in dirs + files:
+            full = os.path.join(root, name)
+            broken_symlink = os.path.lexists(full) and not os.path.exists(full)
+            if not broken_symlink:
+                os.chown(full, uid, gid)
 
=== added directory 'hooks/charmhelpers/core/services'
=== added file 'hooks/charmhelpers/core/services/__init__.py'
--- hooks/charmhelpers/core/services/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/services/__init__.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,2 @@
+from .base import *
+from .helpers import *
 
=== added file 'hooks/charmhelpers/core/services/base.py'
--- hooks/charmhelpers/core/services/base.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/services/base.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,305 @@
+import os
+import re
+import json
+from collections import Iterable
+
+from charmhelpers.core import host
+from charmhelpers.core import hookenv
+
+
+__all__ = ['ServiceManager', 'ManagerCallback',
+           'PortManagerCallback', 'open_ports', 'close_ports', 'manage_ports',
+           'service_restart', 'service_stop']
+
+
+class ServiceManager(object):
+    def __init__(self, services=None):
+        """
+        Register a list of services, given their definitions.
+
+        Traditional charm authoring is focused on implementing hooks.  That is,
+        the charm author is thinking in terms of "What hook am I handling; what
+        does this hook need to do?"  However, in most cases, the real question
+        should be "Do I have the information I need to configure and start this
+        piece of software and, if so, what are the steps for doing so?"  The
+        ServiceManager framework tries to bring the focus to the data and the
+        setup tasks, in the most declarative way possible.
+
+        Service definitions are dicts in the following formats (all keys except
+        'service' are optional)::
+
+            {
+                "service": <service name>,
+                "required_data": <list of required data contexts>,
+                "data_ready": <one or more callbacks>,
+                "data_lost": <one or more callbacks>,
+                "start": <one or more callbacks>,
+                "stop": <one or more callbacks>,
+                "ports": <list of ports to manage>,
+            }
+
+        The 'required_data' list should contain dicts of required data (or
+        dependency managers that act like dicts and know how to collect the data).
+        Only when all items in the 'required_data' list are populated are the list
+        of 'data_ready' and 'start' callbacks executed.  See `is_ready()` for more
+        information.
+
+        The 'data_ready' value should be either a single callback, or a list of
+        callbacks, to be called when all items in 'required_data' pass `is_ready()`.
+        Each callback will be called with the service name as the only parameter.
+        After all of the 'data_ready' callbacks are called, the 'start' callbacks
+        are fired.
+
+        The 'data_lost' value should be either a single callback, or a list of
+        callbacks, to be called when a 'required_data' item no longer passes
+        `is_ready()`.  Each callback will be called with the service name as the
+        only parameter.  After all of the 'data_lost' callbacks are called,
+        the 'stop' callbacks are fired.
+
+        The 'start' value should be either a single callback, or a list of
+        callbacks, to be called when starting the service, after the 'data_ready'
+        callbacks are complete.  Each callback will be called with the service
+        name as the only parameter.  This defaults to
+        `[host.service_start, services.open_ports]`.
+
+        The 'stop' value should be either a single callback, or a list of
+        callbacks, to be called when stopping the service.  If the service is
+        being stopped because it no longer has all of its 'required_data', this
+        will be called after all of the 'data_lost' callbacks are complete.
+        Each callback will be called with the service name as the only parameter.
+        This defaults to `[services.close_ports, host.service_stop]`.
+
+        The 'ports' value should be a list of ports to manage.  The default
+        'start' handler will open the ports after the service is started,
+        and the default 'stop' handler will close the ports prior to stopping
+        the service.
+
+
+        Examples:
+
+        The following registers an Upstart service called bingod that depends on
+        a mongodb relation and which runs a custom `db_migrate` function prior to
+        restarting the service, and a Runit service called spadesd::
+
+            manager = services.ServiceManager([
+                {
+                    'service': 'bingod',
+                    'ports': [80, 443],
+                    'required_data': [MongoRelation(), config(), {'my': 'data'}],
+                    'data_ready': [
+                        services.template(source='bingod.conf'),
+                        services.template(source='bingod.ini',
+                                          target='/etc/bingod.ini',
+                                          owner='bingo', perms=0400),
+                    ],
+                },
+                {
+                    'service': 'spadesd',
+                    'data_ready': services.template(source='spadesd_run.j2',
+                                                    target='/etc/sv/spadesd/run',
+                                                    perms=0555),
+                    'start': runit_start,
+                    'stop': runit_stop,
+                },
+            ])
+            manager.manage()
+        """
+        self._ready_file = os.path.join(hookenv.charm_dir(), 'READY-SERVICES.json')
+        self._ready = None
+        self.services = {}
+        for service in services or []:
+            service_name = service['service']
+            self.services[service_name] = service
+
+    def manage(self):
+        """
+        Handle the current hook by doing The Right Thing with the registered services.
+        """
+        hook_name = hookenv.hook_name()
+        if hook_name == 'stop':
+            self.stop_services()
+        else:
+            self.provide_data()
+            self.reconfigure_services()
+
+    def provide_data(self):
+        hook_name = hookenv.hook_name()
+        for service in self.services.values():
+            for provider in service.get('provided_data', []):
+                if re.match(r'{}-relation-(joined|changed)'.format(provider.name), hook_name):
+                    data = provider.provide_data()
+                    if provider._is_ready(data):
+                        hookenv.relation_set(None, data)
+
+    def reconfigure_services(self, *service_names):
+        """
+        Update all files for one or more registered services, and,
+        if ready, optionally restart them.
+
+        If no service names are given, reconfigures all registered services.
+        """
+        for service_name in service_names or self.services.keys():
+            if self.is_ready(service_name):
+                self.fire_event('data_ready', service_name)
+                self.fire_event('start', service_name, default=[
+                    service_restart,
+                    manage_ports])
+                self.save_ready(service_name)
+            else:
+                if self.was_ready(service_name):
+                    self.fire_event('data_lost', service_name)
+                self.fire_event('stop', service_name, default=[
+                    manage_ports,
+                    service_stop])
+                self.save_lost(service_name)
+
+    def stop_services(self, *service_names):
+        """
+        Stop one or more registered services, by name.
+
+        If no service names are given, stops all registered services.
+        """
+        for service_name in service_names or self.services.keys():
+            self.fire_event('stop', service_name, default=[
+                manage_ports,
+                service_stop])
+
+    def get_service(self, service_name):
+        """
+        Given the name of a registered service, return its service definition.
+        """
+        service = self.services.get(service_name)
+        if not service:
+            raise KeyError('Service not registered: %s' % service_name)
+        return service
+
+    def fire_event(self, event_name, service_name, default=None):
+        """
+        Fire a data_ready, data_lost, start, or stop event on a given service.
+        """
+        service = self.get_service(service_name)
+        callbacks = service.get(event_name, default)
+        if not callbacks:
+            return
+        if not isinstance(callbacks, Iterable):
+            callbacks = [callbacks]
+        for callback in callbacks:
+            if isinstance(callback, ManagerCallback):
+                callback(self, service_name, event_name)
+            else:
+                callback(service_name)
+
+    def is_ready(self, service_name):
+        """
+        Determine if a registered service is ready, by checking its 'required_data'.
+
+        A 'required_data' item can be any mapping type, and is considered ready
+        if `bool(item)` evaluates as True.
+        """
+        service = self.get_service(service_name)
+        reqs = service.get('required_data', [])
+        return all(bool(req) for req in reqs)
+
+    def _load_ready_file(self):
+        if self._ready is not None:
+            return
+        if os.path.exists(self._ready_file):
+            with open(self._ready_file) as fp:
+                self._ready = set(json.load(fp))
+        else:
+            self._ready = set()
+
+    def _save_ready_file(self):
+        if self._ready is None:
+            return
+        with open(self._ready_file, 'w') as fp:
+            json.dump(list(self._ready), fp)
+
+    def save_ready(self, service_name):
+        """
+        Save an indicator that the given service is now data_ready.
+        """
+        self._load_ready_file()
+        self._ready.add(service_name)
+        self._save_ready_file()
+
+    def save_lost(self, service_name):
+        """
+        Save an indicator that the given service is no longer data_ready.
+        """
+        self._load_ready_file()
+        self._ready.discard(service_name)
+        self._save_ready_file()
+
+    def was_ready(self, service_name):
+        """
+        Determine if the given service was previously data_ready.
+        """
+        self._load_ready_file()
+        return service_name in self._ready
+
+
+class ManagerCallback(object):
+    """
+    Special case of a callback that takes the `ServiceManager` instance
+    in addition to the service name.
+
+    Subclasses should implement `__call__` which should accept three parameters:
+
+        * `manager`       The `ServiceManager` instance
+        * `service_name`  The name of the service it's being triggered for
+        * `event_name`    The name of the event that this callback is handling
+    """
+    def __call__(self, manager, service_name, event_name):
+        raise NotImplementedError()
+
+
+class PortManagerCallback(ManagerCallback):
+    """
+    Callback class that will open or close ports, for use as either
+    a start or stop action.
+    """
+    def __call__(self, manager, service_name, event_name):
+        service = manager.get_service(service_name)
+        new_ports = service.get('ports', [])
+        port_file = os.path.join(hookenv.charm_dir(), '.{}.ports'.format(service_name))
+        if os.path.exists(port_file):
+            with open(port_file) as fp:
+                old_ports = fp.read().split(',')
+            for old_port in old_ports:
+                if bool(old_port):
+                    old_port = int(old_port)
+                    if old_port not in new_ports:
+                        hookenv.close_port(old_port)
+        with open(port_file, 'w') as fp:
+            fp.write(','.join(str(port) for port in new_ports))
+        for port in new_ports:
+            if event_name == 'start':
+                hookenv.open_port(port)
+            elif event_name == 'stop':
+                hookenv.close_port(port)
+
+
+def service_stop(service_name):
+    """
+    Wrapper around host.service_stop to prevent spurious "unknown service"
+    messages in the logs.
+    """
+    if host.service_running(service_name):
+        host.service_stop(service_name)
+
+
+def service_restart(service_name):
+    """
+    Wrapper around host.service_restart to prevent spurious "unknown service"
+    messages in the logs.
+    """
+    if host.service_available(service_name):
+        if host.service_running(service_name):
+            host.service_restart(service_name)
+        else:
+            host.service_start(service_name)
+
+
+# Convenience aliases
+open_ports = close_ports = manage_ports = PortManagerCallback()
 
=== added file 'hooks/charmhelpers/core/services/helpers.py'
--- hooks/charmhelpers/core/services/helpers.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/services/helpers.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,125 @@
+from charmhelpers.core import hookenv
+from charmhelpers.core import templating
+
+from charmhelpers.core.services.base import ManagerCallback
+
+
+__all__ = ['RelationContext', 'TemplateCallback',
+           'render_template', 'template']
+
+
+class RelationContext(dict):
+    """
+    Base class for a context generator that gets relation data from juju.
+
+    Subclasses must provide the attributes `name`, which is the name of the
+    interface of interest, `interface`, which is the type of the interface of
+    interest, and `required_keys`, which is the set of keys required for the
+    relation to be considered complete.  The data for all interfaces matching
+    the `name` attribute that are complete will used to populate the dictionary
+    values (see `get_data`, below).
+
+    The generated context will be namespaced under the interface type, to prevent
+    potential naming conflicts.
+    """
+    name = None
+    interface = None
+    required_keys = []
+
+    def __init__(self, *args, **kwargs):
+        super(RelationContext, self).__init__(*args, **kwargs)
+        self.get_data()
+
+    def __bool__(self):
+        """
+        Returns True if all of the required_keys are available.
+        """
+        return self.is_ready()
+
+    __nonzero__ = __bool__
+
+    def __repr__(self):
+        return super(RelationContext, self).__repr__()
+
+    def is_ready(self):
+        """
+        Returns True if all of the `required_keys` are available from any units.
+        """
+        ready = len(self.get(self.name, [])) > 0
+        if not ready:
+            hookenv.log('Incomplete relation: {}'.format(self.__class__.__name__), hookenv.DEBUG)
+        return ready
+
+    def _is_ready(self, unit_data):
+        """
+        Helper method that tests a set of relation data and returns True if
+        all of the `required_keys` are present.
+        """
+        return set(unit_data.keys()).issuperset(set(self.required_keys))
+
+    def get_data(self):
+        """
+        Retrieve the relation data for each unit involved in a relation and,
+        if complete, store it in a list under `self[self.name]`.  This
+        is automatically called when the RelationContext is instantiated.
+
+        The units are sorted lexographically first by the service ID, then by
+        the unit ID.  Thus, if an interface has two other services, 'db:1'
+        and 'db:2', with 'db:1' having two units, 'wordpress/0' and 'wordpress/1',
+        and 'db:2' having one unit, 'mediawiki/0', all of which have a complete
+        set of data, the relation data for the units will be stored in the
+        order: 'wordpress/0', 'wordpress/1', 'mediawiki/0'.
+
+        If you only care about a single unit on the relation, you can just
+        access it as `{{ interface[0]['key'] }}`.  However, if you can at all
+        support multiple units on a relation, you should iterate over the list,
+        like::
+
+            {% for unit in interface -%}
+                {{ unit['key'] }}{% if not loop.last %},{% endif %}
+            {%- endfor %}
+
+        Note that since all sets of relation data from all related services and
+        units are in a single list, if you need to know which service or unit a
+        set of data came from, you'll need to extend this class to preserve
+        that information.
+        """
+        if not hookenv.relation_ids(self.name):
+            return
+
+        ns = self.setdefault(self.name, [])
+        for rid in sorted(hookenv.relation_ids(self.name)):
+            for unit in sorted(hookenv.related_units(rid)):
+                reldata = hookenv.relation_get(rid=rid, unit=unit)
+                if self._is_ready(reldata):
+                    ns.append(reldata)
+
+    def provide_data(self):
+        """
+        Return data to be relation_set for this interface.
+        """
+        return {}
+
+
+class TemplateCallback(ManagerCallback):
+    """
+    Callback class that will render a template, for use as a ready action.
+    """
+    def __init__(self, source, target, owner='root', group='root', perms=0444):
+        self.source = source
+        self.target = target
+        self.owner = owner
+        self.group = group
+        self.perms = perms
+
+    def __call__(self, manager, service_name, event_name):
+        service = manager.get_service(service_name)
+        context = {}
+        for ctx in service.get('required_data', []):
+            context.update(ctx)
+        templating.render(self.source, self.target, context,
+                          self.owner, self.group, self.perms)
+
+
+# Convenience aliases for templates
+render_template = template = TemplateCallback
 
=== added file 'hooks/charmhelpers/core/templating.py'
--- hooks/charmhelpers/core/templating.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/templating.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,51 @@
+import os
+
+from charmhelpers.core import host
+from charmhelpers.core import hookenv
+
+
+def render(source, target, context, owner='root', group='root', perms=0444, templates_dir=None):
+    """
+    Render a template.
+
+    The `source` path, if not absolute, is relative to the `templates_dir`.
+
+    The `target` path should be absolute.
+
+    The context should be a dict containing the values to be replaced in the
+    template.
+
+    The `owner`, `group`, and `perms` options will be passed to `write_file`.
+
+    If omitted, `templates_dir` defaults to the `templates` folder in the charm.
+
+    Note: Using this requires python-jinja2; if it is not installed, calling
+    this will attempt to use charmhelpers.fetch.apt_install to install it.
+    """
+    try:
+        from jinja2 import FileSystemLoader, Environment, exceptions
+    except ImportError:
+        try:
+            from charmhelpers.fetch import apt_install
+        except ImportError:
+            hookenv.log('Could not import jinja2, and could not import '
+                        'charmhelpers.fetch to install it',
+                        level=hookenv.ERROR)
+            raise
+        apt_install('python-jinja2', fatal=True)
+        from jinja2 import FileSystemLoader, Environment, exceptions
+
+    if templates_dir is None:
+        templates_dir = os.path.join(hookenv.charm_dir(), 'templates')
+    loader = Environment(loader=FileSystemLoader(templates_dir))
+    try:
+        source = source
+        template = loader.get_template(source)
+    except exceptions.TemplateNotFound as e:
+        hookenv.log('Could not load template %s from %s.' %
+                    (source, templates_dir),
+                    level=hookenv.ERROR)
+        raise e
+    content = template.render(context)
+    host.mkdir(os.path.dirname(target))
+    host.write_file(target, content, owner, group, perms)
 
=== added directory 'hooks/charmhelpers/fetch'
=== added file 'hooks/charmhelpers/fetch/__init__.py'
--- hooks/charmhelpers/fetch/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/fetch/__init__.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,394 @@
+import importlib
+from tempfile import NamedTemporaryFile
+import time
+from yaml import safe_load
+from charmhelpers.core.host import (
+    lsb_release
+)
+from urlparse import (
+    urlparse,
+    urlunparse,
+)
+import subprocess
+from charmhelpers.core.hookenv import (
+    config,
+    log,
+)
+import os
+
+
+CLOUD_ARCHIVE = """# Ubuntu Cloud Archive
+deb http://ubuntu-cloud.archive.canonical.com/ubuntu {} main
+"""
+PROPOSED_POCKET = """# Proposed
+deb http://archive.ubuntu.com/ubuntu {}-proposed main universe multiverse restricted
+"""
+CLOUD_ARCHIVE_POCKETS = {
+    # Folsom
+    'folsom': 'precise-updates/folsom',
+    'precise-folsom': 'precise-updates/folsom',
+    'precise-folsom/updates': 'precise-updates/folsom',
+    'precise-updates/folsom': 'precise-updates/folsom',
+    'folsom/proposed': 'precise-proposed/folsom',
+    'precise-folsom/proposed': 'precise-proposed/folsom',
+    'precise-proposed/folsom': 'precise-proposed/folsom',
+    # Grizzly
+    'grizzly': 'precise-updates/grizzly',
+    'precise-grizzly': 'precise-updates/grizzly',
+    'precise-grizzly/updates': 'precise-updates/grizzly',
+    'precise-updates/grizzly': 'precise-updates/grizzly',
+    'grizzly/proposed': 'precise-proposed/grizzly',
+    'precise-grizzly/proposed': 'precise-proposed/grizzly',
+    'precise-proposed/grizzly': 'precise-proposed/grizzly',
+    # Havana
+    'havana': 'precise-updates/havana',
+    'precise-havana': 'precise-updates/havana',
+    'precise-havana/updates': 'precise-updates/havana',
+    'precise-updates/havana': 'precise-updates/havana',
+    'havana/proposed': 'precise-proposed/havana',
+    'precise-havana/proposed': 'precise-proposed/havana',
+    'precise-proposed/havana': 'precise-proposed/havana',
+    # Icehouse
+    'icehouse': 'precise-updates/icehouse',
+    'precise-icehouse': 'precise-updates/icehouse',
+    'precise-icehouse/updates': 'precise-updates/icehouse',
+    'precise-updates/icehouse': 'precise-updates/icehouse',
+    'icehouse/proposed': 'precise-proposed/icehouse',
+    'precise-icehouse/proposed': 'precise-proposed/icehouse',
+    'precise-proposed/icehouse': 'precise-proposed/icehouse',
+    # Juno
+    'juno': 'trusty-updates/juno',
+    'trusty-juno': 'trusty-updates/juno',
+    'trusty-juno/updates': 'trusty-updates/juno',
+    'trusty-updates/juno': 'trusty-updates/juno',
+    'juno/proposed': 'trusty-proposed/juno',
+    'juno/proposed': 'trusty-proposed/juno',
+    'trusty-juno/proposed': 'trusty-proposed/juno',
+    'trusty-proposed/juno': 'trusty-proposed/juno',
+}
+
+# The order of this list is very important. Handlers should be listed in from
+# least- to most-specific URL matching.
+FETCH_HANDLERS = (
+    'charmhelpers.fetch.archiveurl.ArchiveUrlFetchHandler',
+    'charmhelpers.fetch.bzrurl.BzrUrlFetchHandler',
+)
+
+APT_NO_LOCK = 100  # The return code for "couldn't acquire lock" in APT.
+APT_NO_LOCK_RETRY_DELAY = 10  # Wait 10 seconds between apt lock checks.
+APT_NO_LOCK_RETRY_COUNT = 30  # Retry to acquire the lock X times.
+
+
+class SourceConfigError(Exception):
+    pass
+
+
+class UnhandledSource(Exception):
+    pass
+
+
+class AptLockError(Exception):
+    pass
+
+
+class BaseFetchHandler(object):
+
+    """Base class for FetchHandler implementations in fetch plugins"""
+
+    def can_handle(self, source):
+        """Returns True if the source can be handled. Otherwise returns
+        a string explaining why it cannot"""
+        return "Wrong source type"
+
+    def install(self, source):
+        """Try to download and unpack the source. Return the path to the
+        unpacked files or raise UnhandledSource."""
+        raise UnhandledSource("Wrong source type {}".format(source))
+
+    def parse_url(self, url):
+        return urlparse(url)
+
+    def base_url(self, url):
+        """Return url without querystring or fragment"""
+        parts = list(self.parse_url(url))
+        parts[4:] = ['' for i in parts[4:]]
+        return urlunparse(parts)
+
+
+def filter_installed_packages(packages):
+    """Returns a list of packages that require installation"""
+    import apt_pkg
+    apt_pkg.init()
+
+    # Tell apt to build an in-memory cache to prevent race conditions (if
+    # another process is already building the cache).
+    apt_pkg.config.set("Dir::Cache::pkgcache", "")
+    apt_pkg.config.set("Dir::Cache::srcpkgcache", "")
+
+    cache = apt_pkg.Cache()
+    _pkgs = []
+    for package in packages:
+        try:
+            p = cache[package]
+            p.current_ver or _pkgs.append(package)
+        except KeyError:
+            log('Package {} has no installation candidate.'.format(package),
+                level='WARNING')
+            _pkgs.append(package)
+    return _pkgs
+
+
+def apt_install(packages, options=None, fatal=False):
+    """Install one or more packages"""
+    if options is None:
+        options = ['--option=Dpkg::Options::=--force-confold']
+
+    cmd = ['apt-get', '--assume-yes']
+    cmd.extend(options)
+    cmd.append('install')
+    if isinstance(packages, basestring):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Installing {} with options: {}".format(packages,
+                                                options))
+    _run_apt_command(cmd, fatal)
+
+
+def apt_upgrade(options=None, fatal=False, dist=False):
+    """Upgrade all packages"""
+    if options is None:
+        options = ['--option=Dpkg::Options::=--force-confold']
+
+    cmd = ['apt-get', '--assume-yes']
+    cmd.extend(options)
+    if dist:
+        cmd.append('dist-upgrade')
+    else:
+        cmd.append('upgrade')
+    log("Upgrading with options: {}".format(options))
+    _run_apt_command(cmd, fatal)
+
+
+def apt_update(fatal=False):
+    """Update local apt cache"""
+    cmd = ['apt-get', 'update']
+    _run_apt_command(cmd, fatal)
+
+
+def apt_purge(packages, fatal=False):
+    """Purge one or more packages"""
+    cmd = ['apt-get', '--assume-yes', 'purge']
+    if isinstance(packages, basestring):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Purging {}".format(packages))
+    _run_apt_command(cmd, fatal)
+
+
+def apt_hold(packages, fatal=False):
+    """Hold one or more packages"""
+    cmd = ['apt-mark', 'hold']
+    if isinstance(packages, basestring):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Holding {}".format(packages))
+
+    if fatal:
+        subprocess.check_call(cmd)
+    else:
+        subprocess.call(cmd)
+
+
+def add_source(source, key=None):
+    """Add a package source to this system.
+
+    @param source: a URL or sources.list entry, as supported by
+    add-apt-repository(1). Examples:
+        ppa:charmers/example
+        deb https://stub:[e-mail]/ubuntu trusty main
+
+    In addition:
+        'proposed:' may be used to enable the standard 'proposed'
+        pocket for the release.
+        'cloud:' may be used to activate official cloud archive pockets,
+        such as 'cloud:icehouse'
+
+    @param key: A key to be added to the system's APT keyring and used
+    to verify the signatures on packages. Ideally, this should be an
+    ASCII format GPG public key including the block headers. A GPG key
+    id may also be used, but be aware that only insecure protocols are
+    available to retrieve the actual public key from a public keyserver
+    placing your Juju environment at risk. ppa and cloud archive keys
+    are securely added automtically, so sould not be provided.
+    """
+    if source is None:
+        log('Source is not present. Skipping')
+        return
+
+    if (source.startswith('ppa:') or
+        source.startswith('http') or
+        source.startswith('deb ') or
+            source.startswith('cloud-archive:')):
+        subprocess.check_call(['add-apt-repository', '--yes', source])
+    elif source.startswith('cloud:'):
+        apt_install(filter_installed_packages(['ubuntu-cloud-keyring']),
+                    fatal=True)
+        pocket = source.split(':')[-1]
+        if pocket not in CLOUD_ARCHIVE_POCKETS:
+            raise SourceConfigError(
+                'Unsupported cloud: source option %s' %
+                pocket)
+        actual_pocket = CLOUD_ARCHIVE_POCKETS[pocket]
+        with open('/etc/apt/sources.list.d/cloud-archive.list', 'w') as apt:
+            apt.write(CLOUD_ARCHIVE.format(actual_pocket))
+    elif source == 'proposed':
+        release = lsb_release()['DISTRIB_CODENAME']
+        with open('/etc/apt/sources.list.d/proposed.list', 'w') as apt:
+            apt.write(PROPOSED_POCKET.format(release))
+    else:
+        raise SourceConfigError("Unknown source: {!r}".format(source))
+
+    if key:
+        if '-----BEGIN PGP PUBLIC KEY BLOCK-----' in key:
+            with NamedTemporaryFile() as key_file:
+                key_file.write(key)
+                key_file.flush()
+                key_file.seek(0)
+                subprocess.check_call(['apt-key', 'add', '-'], stdin=key_file)
+        else:
+            # Note that hkp: is in no way a secure protocol. Using a
+            # GPG key id is pointless from a security POV unless you
+            # absolutely trust your network and DNS.
+            subprocess.check_call(['apt-key', 'adv', '--keyserver',
+                                   'hkp://keyserver.ubuntu.com:80', '--recv',
+                                   key])
+
+
+def configure_sources(update=False,
+                      sources_var='install_sources',
+                      keys_var='install_keys'):
+    """
+    Configure multiple sources from charm configuration.
+
+    The lists are encoded as yaml fragments in the configuration.
+    The frament needs to be included as a string. Sources and their
+    corresponding keys are of the types supported by add_source().
+
+    Example config:
+        install_sources: |
+          - "ppa:foo"
+          - "http://example.com/repo precise main"
+        install_keys: |
+          - null
+          - "a1b2c3d4"
+
+    Note that 'null' (a.k.a. None) should not be quoted.
+    """
+    sources = safe_load((config(sources_var) or '').strip()) or []
+    keys = safe_load((config(keys_var) or '').strip()) or None
+
+    if isinstance(sources, basestring):
+        sources = [sources]
+
+    if keys is None:
+        for source in sources:
+            add_source(source, None)
+    else:
+        if isinstance(keys, basestring):
+            keys = [keys]
+
+        if len(sources) != len(keys):
+            raise SourceConfigError(
+                'Install sources and keys lists are different lengths')
+        for source, key in zip(sources, keys):
+            add_source(source, key)
+    if update:
+        apt_update(fatal=True)
+
+
+def install_remote(source):
+    """
+    Install a file tree from a remote source
+
+    The specified source should be a url of the form:
+        scheme://[host]/path[#[option=value][&...]]
+
+    Schemes supported are based on this modules submodules
+    Options supported are submodule-specific"""
+    # We ONLY check for True here because can_handle may return a string
+    # explaining why it can't handle a given source.
+    handlers = [h for h in plugins() if h.can_handle(source) is True]
+    installed_to = None
+    for handler in handlers:
+        try:
+            installed_to = handler.install(source)
+        except UnhandledSource:
+            pass
+    if not installed_to:
+        raise UnhandledSource("No handler found for source {}".format(source))
+    return installed_to
+
+
+def install_from_config(config_var_name):
+    charm_config = config()
+    source = charm_config[config_var_name]
+    return install_remote(source)
+
+
+def plugins(fetch_handlers=None):
+    if not fetch_handlers:
+        fetch_handlers = FETCH_HANDLERS
+    plugin_list = []
+    for handler_name in fetch_handlers:
+        package, classname = handler_name.rsplit('.', 1)
+        try:
+            handler_class = getattr(
+                importlib.import_module(package),
+                classname)
+            plugin_list.append(handler_class())
+        except (ImportError, AttributeError):
+            # Skip missing plugins so that they can be ommitted from
+            # installation if desired
+            log("FetchHandler {} not found, skipping plugin".format(
+                handler_name))
+    return plugin_list
+
+
+def _run_apt_command(cmd, fatal=False):
+    """
+    Run an APT command, checking output and retrying if the fatal flag is set
+    to True.
+
+    :param: cmd: str: The apt command to run.
+    :param: fatal: bool: Whether the command's output should be checked and
+        retried.
+    """
+    env = os.environ.copy()
+
+    if 'DEBIAN_FRONTEND' not in env:
+        env['DEBIAN_FRONTEND'] = 'noninteractive'
+
+    if fatal:
+        retry_count = 0
+        result = None
+
+        # If the command is considered "fatal", we need to retry if the apt
+        # lock was not acquired.
+
+        while result is None or result == APT_NO_LOCK:
+            try:
+                result = subprocess.check_call(cmd, env=env)
+            except subprocess.CalledProcessError, e:
+                retry_count = retry_count + 1
+                if retry_count > APT_NO_LOCK_RETRY_COUNT:
+                    raise
+                result = e.returncode
+                log("Couldn't acquire DPKG lock. Will retry in {} seconds."
+                    "".format(APT_NO_LOCK_RETRY_DELAY))
+                time.sleep(APT_NO_LOCK_RETRY_DELAY)
+
+    else:
+        subprocess.call(cmd, env=env)
 
=== added file 'hooks/charmhelpers/fetch/archiveurl.py'
--- hooks/charmhelpers/fetch/archiveurl.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/fetch/archiveurl.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,63 @@
+import os
+import urllib2
+import urlparse
+
+from charmhelpers.fetch import (
+    BaseFetchHandler,
+    UnhandledSource
+)
+from charmhelpers.payload.archive import (
+    get_archive_handler,
+    extract,
+)
+from charmhelpers.core.host import mkdir
+
+
+class ArchiveUrlFetchHandler(BaseFetchHandler):
+    """Handler for archives via generic URLs"""
+    def can_handle(self, source):
+        url_parts = self.parse_url(source)
+        if url_parts.scheme not in ('http', 'https', 'ftp', 'file'):
+            return "Wrong source type"
+        if get_archive_handler(self.base_url(source)):
+            return True
+        return False
+
+    def download(self, source, dest):
+        # propogate all exceptions
+        # URLError, OSError, etc
+        proto, netloc, path, params, query, fragment = urlparse.urlparse(source)
+        if proto in ('http', 'https'):
+            auth, barehost = urllib2.splituser(netloc)
+            if auth is not None:
+                source = urlparse.urlunparse((proto, barehost, path, params, query, fragment))
+                username, password = urllib2.splitpasswd(auth)
+                passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
+                # Realm is set to None in add_password to force the username and password
+                # to be used whatever the realm
+                passman.add_password(None, source, username, password)
+                authhandler = urllib2.HTTPBasicAuthHandler(passman)
+                opener = urllib2.build_opener(authhandler)
+                urllib2.install_opener(opener)
+        response = urllib2.urlopen(source)
+        try:
+            with open(dest, 'w') as dest_file:
+                dest_file.write(response.read())
+        except Exception as e:
+            if os.path.isfile(dest):
+                os.unlink(dest)
+            raise e
+
+    def install(self, source):
+        url_parts = self.parse_url(source)
+        dest_dir = os.path.join(os.environ.get('CHARM_DIR'), 'fetched')
+        if not os.path.exists(dest_dir):
+            mkdir(dest_dir, perms=0755)
+        dld_file = os.path.join(dest_dir, os.path.basename(url_parts.path))
+        try:
+            self.download(source, dld_file)
+        except urllib2.URLError as e:
+            raise UnhandledSource(e.reason)
+        except OSError as e:
+            raise UnhandledSource(e.strerror)
+        return extract(dld_file)
 
=== added file 'hooks/charmhelpers/fetch/bzrurl.py'
--- hooks/charmhelpers/fetch/bzrurl.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/fetch/bzrurl.py	2014-09-09 05:13:17 +0000
@@ -0,0 +1,50 @@
+import os
+from charmhelpers.fetch import (
+    BaseFetchHandler,
+    UnhandledSource
+)
+from charmhelpers.core.host import mkdir
+
+try:
+    from bzrlib.branch import Branch
+except ImportError:
+    from charmhelpers.fetch import apt_install
+    apt_install("python-bzrlib")
+    from bzrlib.branch import Branch
+
+
+class BzrUrlFetchHandler(BaseFetchHandler):
+    """Handler for bazaar branches via generic and lp URLs"""
+    def can_handle(self, source):
+        url_parts = self.parse_url(source)
+        if url_parts.scheme not in ('bzr+ssh', 'lp'):
+            return False
+        else:
+            return True
+
+    def branch(self, source, dest):
+        url_parts = self.parse_url(source)
+        # If we use lp:branchname scheme we need to load plugins
+        if not self.can_handle(source):
+            raise UnhandledSource("Cannot handle {}".format(source))
+        if url_parts.scheme == "lp":
+            from bzrlib.plugin import load_plugins
+            load_plugins()
+        try:
+            remote_branch = Branch.open(source)
+            remote_branch.bzrdir.sprout(dest).open_branch()
+        except Exception as e:
+            raise e
+
+    def install(self, source):
+        url_parts = self.parse_url(source)
+        branch_name = url_parts.path.strip("/").split("/")[-1]
+        dest_dir = os.path.join(os.environ.get('CHARM_DIR'), "fetched",
+                                branch_name)
+        if not os.path.exists(dest_dir):
+            mkdir(dest_dir, perms=0755)
+        try:
+            self.branch(source, dest_dir)
+        except OSError as e:
+            raise UnhandledSource(e.strerror)
+        return dest_dir
 
=== added directory 'hooks/storage-provider.d/ceph'
=== added file 'hooks/storage-provider.d/ceph/ceph-relation-changed'
--- hooks/storage-provider.d/ceph/ceph-relation-changed	1970-01-01 00:00:00 +0000
+++ hooks/storage-provider.d/ceph/ceph-relation-changed	2014-09-09 05:13:17 +0000
@@ -0,0 +1,69 @@
+#!/usr/bin/env python
+import sys
+
+from ceph_common import (
+    SERVICE_NAME,
+    POOL_NAME,
+    TEMPORARY_MOUNT_POINT,
+    RDB_IMG,
+    BLK_DEVICE,
+)
+
+from charmhelpers.core.hookenv import (
+    relation_get,
+    config,
+    log,
+)
+
+from charmhelpers.contrib.storage.linux import ceph
+
+"""
+This will mount a ceph image to a temporary location when the ceph relation
+is ready.
+
+Later, when the data relation fires and a mountpoint is define, the temporary
+mountpoint will be remounted.
+"""
+
+
+REPLICA_COUNT = 3
+
+
+def main():
+    config_data = config()
+
+    # This shouldn't clash since the pool name should be a good enough
+    # "namespace".
+
+    volume_size_gb = config_data.get("volume_size", None)  # in Gb.
+    volume_size = volume_size_gb * 1024
+
+    auth = relation_get("auth")
+    key = relation_get("key")
+    use_syslog = relation_get("use-syslog")
+
+    relation_data = [auth, key, use_syslog]
+
+    if None in relation_data:
+        log("Not all relation data received: '%s'" % relation_data)
+        sys.exit(0)
+
+    log("Configuring ceph client...")
+    ceph.configure(
+        service=SERVICE_NAME, key=key, auth=auth, use_syslog=use_syslog)
+
+    log("Mounting ceph image to temporary location '%s'"
+        "" % TEMPORARY_MOUNT_POINT)
+    ceph.ensure_ceph_storage(
+        service=SERVICE_NAME,
+        pool=POOL_NAME,
+        rdb_img=RDB_IMG,
+        sizemb=volume_size,
+        fstype="ext4",
+        mount_point=TEMPORARY_MOUNT_POINT,
+        blk_device=BLK_DEVICE,
+        rdb_pool_replicas=REPLICA_COUNT)
+
+
+if __name__ == "__main__":
+    main()
 
=== added file 'hooks/storage-provider.d/ceph/config-changed'
--- hooks/storage-provider.d/ceph/config-changed	1970-01-01 00:00:00 +0000
+++ hooks/storage-provider.d/ceph/config-changed	2014-09-09 05:13:17 +0000
@@ -0,0 +1,6 @@
+#!/usr/bin/env python
+from charmhelpers.contrib.storage.linux.ceph import (
+    install,
+)
+
+install()
 
=== added file 'hooks/storage-provider.d/ceph/data-relation-changed'
--- hooks/storage-provider.d/ceph/data-relation-changed	1970-01-01 00:00:00 +0000
+++ hooks/storage-provider.d/ceph/data-relation-changed	2014-09-09 05:13:17 +0000
@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+import sys
+from ceph_common import (
+    TEMPORARY_MOUNT_POINT,
+    BLK_DEVICE,
+)
+from charmhelpers.core.hookenv import (
+    relation_get,
+    relation_set,
+    log,
+)
+
+from charmhelpers.core.host import (
+    mount,
+    mounts,
+    #umount,
+)
+
+
+def main():
+
+    # Noop until mountpoint is set.
+    mountpoint = relation_get("mountpoint")
+    if mountpoint is None:
+        log("No mountpoint received from the data relation. Noop.")
+        sys.exit(0)  # No mountpoint requested yet - noop
+
+    # If the mountpoint is set, let's remount the temporary folder.
+    actual_mounts = mounts()
+    log("Getting mounts: %s" % actual_mounts)
+    mountpoints = [point[0] for point in actual_mounts]  # returns a list of 2-lists
+
+    if TEMPORARY_MOUNT_POINT in mountpoints:
+        log("Found ceph block device, remounting to '%s'" % mountpoint)
+        # The ceph image is ready and mounted - let's remount it to the desired
+        # mountpoint.
+        mount(BLK_DEVICE, mountpoint)
+        log("Mountpoint ready, notifying data relation.")
+        relation_set("mountpoint", mountpoint)
+    else:
+        log("Temporary mountpoint not found (yet?). Noop.")
+        sys.exit(0)
+
+if __name__ == "__main__":
+    main()
 
=== modified file 'metadata.yaml'
--- metadata.yaml	2014-02-10 16:58:17 +0000
+++ metadata.yaml	2014-09-09 05:13:17 +0000
@@ -18,3 +18,5 @@
         interface: mount
     block-storage:
         interface: volume-request
+    ceph:
+        interface: ceph-client