Merge lp:~niedbalski/charms/precise/mysql/precise-syncup into lp:charms/mysql

[Jorge Niedbalski]

Trusty to precise <-> syncup

[Review Queue (review-queue)]

This items has failed automated testing! Results available here http://reports.vapour.ws/charm-tests/charm-bundle-test-10690-results

review: Needs Fixing (automated testing)

[Whit Morriss (whitmo)]

Test failure here seems to be incidental rather than an issue of concern. Confirmed manual deployment works for precise on local and aws. Confirm replication as described in README works on AWS.

LGTM? +1

[Review Queue (review-queue)]

The results (PASS) are in and available here: http://reports.vapour.ws/charm-tests/charm-bundle-test-10913-results

review: Approve (automated testing)

[Review Queue (review-queue)]

The results (PASS) are in and available here: http://reports.vapour.ws/charm-tests/charm-bundle-test-10919-results

review: Approve (automated testing)

[Tim Van Steenburgh (tvansteenburgh)]

+1 LGTM.

review: Approve

=== added file '.bzrignore'
--- .bzrignore	1970-01-01 00:00:00 +0000
+++ .bzrignore	2014-12-11 14:18:46 +0000
@@ -0,0 +1,1 @@
+bin/

=== modified file 'Makefile'
--- Makefile	2014-03-04 17:28:10 +0000
+++ Makefile	2014-12-11 14:18:46 +0000
@@ -11,5 +11,10 @@
 #	@echo Starting tests...
 #	@$(PYTHON) /usr/bin/nosetests --nologcapture unit_tests
 
-sync:
-	@charm-helper-sync -c charm-helpers.yaml
+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 'README.md'
--- README.md	2014-06-12 22:06:54 +0000
+++ README.md	2014-12-11 14:18:46 +0000
@@ -12,7 +12,7 @@
 
     juju deploy mysql
 
-Once deployed, you can retrive the MySQL root user password by logging in to the machine via `juju ssh` and readin the `/var/lib/mysql/mysql.passwd` file. To log in as root MySQL User at the MySQL console you can issue the following:
+Once deployed, you can retrieve the MySQL root user password by logging in to the machine via `juju ssh` and readin the `/var/lib/mysql/mysql.passwd` file. To log in as root MySQL User at the MySQL console you can issue the following:
 
     juju ssh mysql/0
     mysql -u root -p`sudo cat /var/lib/mysql/mysql.passwd`

=== modified file 'charm-helpers.yaml'
--- charm-helpers.yaml	2014-02-19 14:49:31 +0000
+++ charm-helpers.yaml	2014-12-11 14:18:46 +0000
@@ -1,5 +1,7 @@
 branch: lp:charm-helpers
 destination: hooks/charmhelpers
 include:
+    - __init__
     - core
     - fetch
+    - contrib.network.ip

=== modified file 'config.yaml'
--- config.yaml	2014-11-05 14:54:57 +0000
+++ config.yaml	2014-12-11 14:18:46 +0000
@@ -69,7 +69,7 @@
           image name exists in Ceph, it will be re-used and the data will be
           overwritten.
     ceph-osd-replication-count:
-        default: 2
+        default: 3
         type: int
         description: |
           This value dictates the number of replicas ceph must make of any
@@ -106,3 +106,19 @@
               juju-myservice-0
           If you're running multiple environments with the same services in them
           this allows you to differentiate between them.
+    prefer-ipv6:
+        type: boolean
+        default: False
+        description: |
+          If True enables IPv6 support. The charm will expect network interfaces
+          to be configured with an IPv6 address. If set to False (default) IPv4
+          is expected.
+          .
+          NOTE: these charms do not currently support IPv6 privacy extension. In
+          order for this charm to function correctly, the privacy extension must
+          be disabled and a non-temporary address must be configured/available
+          on your network interface.
+    bind-address:
+        default: '0.0.0.0'
+        type: string
+        description: "mysql bind host address"

=== modified file 'hooks/charmhelpers/__init__.py'
--- hooks/charmhelpers/__init__.py	2014-02-19 14:49:31 +0000
+++ hooks/charmhelpers/__init__.py	2014-12-11 14:18:46 +0000
@@ -0,0 +1,22 @@
+# Bootstrap charm-helpers, installing its dependencies if necessary using
+# only standard libraries.
+import subprocess
+import sys
+
+try:
+    import six  # flake8: noqa
+except ImportError:
+    if sys.version_info.major == 2:
+        subprocess.check_call(['apt-get', 'install', '-y', 'python-six'])
+    else:
+        subprocess.check_call(['apt-get', 'install', '-y', 'python3-six'])
+    import six  # flake8: noqa
+
+try:
+    import yaml  # flake8: noqa
+except ImportError:
+    if sys.version_info.major == 2:
+        subprocess.check_call(['apt-get', 'install', '-y', 'python-yaml'])
+    else:
+        subprocess.check_call(['apt-get', 'install', '-y', 'python3-yaml'])
+    import yaml  # flake8: noqa

=== added directory 'hooks/charmhelpers/contrib/network'
=== added file 'hooks/charmhelpers/contrib/network/__init__.py'
=== added file 'hooks/charmhelpers/contrib/network/ip.py'
--- hooks/charmhelpers/contrib/network/ip.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/network/ip.py	2014-12-11 14:18:46 +0000
@@ -0,0 +1,351 @@
+import glob
+import re
+import subprocess
+
+from functools import partial
+
+from charmhelpers.core.hookenv import unit_get
+from charmhelpers.fetch import apt_install
+from charmhelpers.core.hookenv import (
+    log
+)
+
+try:
+    import netifaces
+except ImportError:
+    apt_install('python-netifaces')
+    import netifaces
+
+try:
+    import netaddr
+except ImportError:
+    apt_install('python-netaddr')
+    import netaddr
+
+
+def _validate_cidr(network):
+    try:
+        netaddr.IPNetwork(network)
+    except (netaddr.core.AddrFormatError, ValueError):
+        raise ValueError("Network (%s) is not in CIDR presentation format" %
+                         network)
+
+
+def no_ip_found_error_out(network):
+    errmsg = ("No IP address found in network: %s" % network)
+    raise ValueError(errmsg)
+
+
+def get_address_in_network(network, fallback=None, fatal=False):
+    """Get an IPv4 or IPv6 address within the network from the host.
+
+    :param network (str): CIDR presentation format. For example,
+        '192.168.1.0/24'.
+    :param fallback (str): If no address is found, return fallback.
+    :param fatal (boolean): If no address is found, fallback is not
+        set and fatal is True then exit(1).
+    """
+    if network is None:
+        if fallback is not None:
+            return fallback
+
+        if fatal:
+            no_ip_found_error_out(network)
+        else:
+            return None
+
+    _validate_cidr(network)
+    network = netaddr.IPNetwork(network)
+    for iface in netifaces.interfaces():
+        addresses = netifaces.ifaddresses(iface)
+        if network.version == 4 and netifaces.AF_INET in addresses:
+            addr = addresses[netifaces.AF_INET][0]['addr']
+            netmask = addresses[netifaces.AF_INET][0]['netmask']
+            cidr = netaddr.IPNetwork("%s/%s" % (addr, netmask))
+            if cidr in network:
+                return str(cidr.ip)
+
+        if network.version == 6 and netifaces.AF_INET6 in addresses:
+            for addr in addresses[netifaces.AF_INET6]:
+                if not addr['addr'].startswith('fe80'):
+                    cidr = netaddr.IPNetwork("%s/%s" % (addr['addr'],
+                                                        addr['netmask']))
+                    if cidr in network:
+                        return str(cidr.ip)
+
+    if fallback is not None:
+        return fallback
+
+    if fatal:
+        no_ip_found_error_out(network)
+
+    return None
+
+
+def is_ipv6(address):
+    """Determine whether provided address is IPv6 or not."""
+    try:
+        address = netaddr.IPAddress(address)
+    except netaddr.AddrFormatError:
+        # probably a hostname - so not an address at all!
+        return False
+
+    return address.version == 6
+
+
+def is_address_in_network(network, address):
+    """
+    Determine whether the provided address is within a network range.
+
+    :param network (str): CIDR presentation format. For example,
+        '192.168.1.0/24'.
+    :param address: An individual IPv4 or IPv6 address without a net
+        mask or subnet prefix. For example, '192.168.1.1'.
+    :returns boolean: Flag indicating whether address is in network.
+    """
+    try:
+        network = netaddr.IPNetwork(network)
+    except (netaddr.core.AddrFormatError, ValueError):
+        raise ValueError("Network (%s) is not in CIDR presentation format" %
+                         network)
+
+    try:
+        address = netaddr.IPAddress(address)
+    except (netaddr.core.AddrFormatError, ValueError):
+        raise ValueError("Address (%s) is not in correct presentation format" %
+                         address)
+
+    if address in network:
+        return True
+    else:
+        return False
+
+
+def _get_for_address(address, key):
+    """Retrieve an attribute of or the physical interface that
+    the IP address provided could be bound to.
+
+    :param address (str): An individual IPv4 or IPv6 address without a net
+        mask or subnet prefix. For example, '192.168.1.1'.
+    :param key: 'iface' for the physical interface name or an attribute
+        of the configured interface, for example 'netmask'.
+    :returns str: Requested attribute or None if address is not bindable.
+    """
+    address = netaddr.IPAddress(address)
+    for iface in netifaces.interfaces():
+        addresses = netifaces.ifaddresses(iface)
+        if address.version == 4 and netifaces.AF_INET in addresses:
+            addr = addresses[netifaces.AF_INET][0]['addr']
+            netmask = addresses[netifaces.AF_INET][0]['netmask']
+            network = netaddr.IPNetwork("%s/%s" % (addr, netmask))
+            cidr = network.cidr
+            if address in cidr:
+                if key == 'iface':
+                    return iface
+                else:
+                    return addresses[netifaces.AF_INET][0][key]
+
+        if address.version == 6 and netifaces.AF_INET6 in addresses:
+            for addr in addresses[netifaces.AF_INET6]:
+                if not addr['addr'].startswith('fe80'):
+                    network = netaddr.IPNetwork("%s/%s" % (addr['addr'],
+                                                           addr['netmask']))
+                    cidr = network.cidr
+                    if address in cidr:
+                        if key == 'iface':
+                            return iface
+                        elif key == 'netmask' and cidr:
+                            return str(cidr).split('/')[1]
+                        else:
+                            return addr[key]
+
+    return None
+
+
+get_iface_for_address = partial(_get_for_address, key='iface')
+
+
+get_netmask_for_address = partial(_get_for_address, key='netmask')
+
+
+def format_ipv6_addr(address):
+    """If address is IPv6, wrap it in '[]' otherwise return None.
+
+    This is required by most configuration files when specifying IPv6
+    addresses.
+    """
+    if is_ipv6(address):
+        return "[%s]" % address
+
+    return None
+
+
+def get_iface_addr(iface='eth0', inet_type='AF_INET', inc_aliases=False,
+                   fatal=True, exc_list=None):
+    """Return the assigned IP address for a given interface, if any."""
+    # Extract nic if passed /dev/ethX
+    if '/' in iface:
+        iface = iface.split('/')[-1]
+
+    if not exc_list:
+        exc_list = []
+
+    try:
+        inet_num = getattr(netifaces, inet_type)
+    except AttributeError:
+        raise Exception("Unknown inet type '%s'" % str(inet_type))
+
+    interfaces = netifaces.interfaces()
+    if inc_aliases:
+        ifaces = []
+        for _iface in interfaces:
+            if iface == _iface or _iface.split(':')[0] == iface:
+                ifaces.append(_iface)
+
+        if fatal and not ifaces:
+            raise Exception("Invalid interface '%s'" % iface)
+
+        ifaces.sort()
+    else:
+        if iface not in interfaces:
+            if fatal:
+                raise Exception("Interface '%s' not found " % (iface))
+            else:
+                return []
+
+        else:
+            ifaces = [iface]
+
+    addresses = []
+    for netiface in ifaces:
+        net_info = netifaces.ifaddresses(netiface)
+        if inet_num in net_info:
+            for entry in net_info[inet_num]:
+                if 'addr' in entry and entry['addr'] not in exc_list:
+                    addresses.append(entry['addr'])
+
+    if fatal and not addresses:
+        raise Exception("Interface '%s' doesn't have any %s addresses." %
+                        (iface, inet_type))
+
+    return sorted(addresses)
+
+
+get_ipv4_addr = partial(get_iface_addr, inet_type='AF_INET')
+
+
+def get_iface_from_addr(addr):
+    """Work out on which interface the provided address is configured."""
+    for iface in netifaces.interfaces():
+        addresses = netifaces.ifaddresses(iface)
+        for inet_type in addresses:
+            for _addr in addresses[inet_type]:
+                _addr = _addr['addr']
+                # link local
+                ll_key = re.compile("(.+)%.*")
+                raw = re.match(ll_key, _addr)
+                if raw:
+                    _addr = raw.group(1)
+
+                if _addr == addr:
+                    log("Address '%s' is configured on iface '%s'" %
+                        (addr, iface))
+                    return iface
+
+    msg = "Unable to infer net iface on which '%s' is configured" % (addr)
+    raise Exception(msg)
+
+
+def sniff_iface(f):
+    """Ensure decorated function is called with a value for iface.
+
+    If no iface provided, inject net iface inferred from unit private address.
+    """
+    def iface_sniffer(*args, **kwargs):
+        if not kwargs.get('iface', None):
+            kwargs['iface'] = get_iface_from_addr(unit_get('private-address'))
+
+        return f(*args, **kwargs)
+
+    return iface_sniffer
+
+
+@sniff_iface
+def get_ipv6_addr(iface=None, inc_aliases=False, fatal=True, exc_list=None,
+                  dynamic_only=True):
+    """Get assigned IPv6 address for a given interface.
+
+    Returns list of addresses found. If no address found, returns empty list.
+
+    If iface is None, we infer the current primary interface by doing a reverse
+    lookup on the unit private-address.
+
+    We currently only support scope global IPv6 addresses i.e. non-temporary
+    addresses. If no global IPv6 address is found, return the first one found
+    in the ipv6 address list.
+    """
+    addresses = get_iface_addr(iface=iface, inet_type='AF_INET6',
+                               inc_aliases=inc_aliases, fatal=fatal,
+                               exc_list=exc_list)
+
+    if addresses:
+        global_addrs = []
+        for addr in addresses:
+            key_scope_link_local = re.compile("^fe80::..(.+)%(.+)")
+            m = re.match(key_scope_link_local, addr)
+            if m:
+                eui_64_mac = m.group(1)
+                iface = m.group(2)
+            else:
+                global_addrs.append(addr)
+
+        if global_addrs:
+            # Make sure any found global addresses are not temporary
+            cmd = ['ip', 'addr', 'show', iface]
+            out = subprocess.check_output(cmd).decode('UTF-8')
+            if dynamic_only:
+                key = re.compile("inet6 (.+)/[0-9]+ scope global dynamic.*")
+            else:
+                key = re.compile("inet6 (.+)/[0-9]+ scope global.*")
+
+            addrs = []
+            for line in out.split('\n'):
+                line = line.strip()
+                m = re.match(key, line)
+                if m and 'temporary' not in line:
+                    # Return the first valid address we find
+                    for addr in global_addrs:
+                        if m.group(1) == addr:
+                            if not dynamic_only or \
+                                    m.group(1).endswith(eui_64_mac):
+                                addrs.append(addr)
+
+            if addrs:
+                return addrs
+
+    if fatal:
+        raise Exception("Interface '%s' does not have a scope global "
+                        "non-temporary ipv6 address." % iface)
+
+    return []
+
+
+def get_bridges(vnic_dir='/sys/devices/virtual/net'):
+    """Return a list of bridges on the system."""
+    b_regex = "%s/*/bridge" % vnic_dir
+    return [x.replace(vnic_dir, '').split('/')[1] for x in glob.glob(b_regex)]
+
+
+def get_bridge_nics(bridge, vnic_dir='/sys/devices/virtual/net'):
+    """Return a list of nics comprising a given bridge on the system."""
+    brif_regex = "%s/%s/brif/*" % (vnic_dir, bridge)
+    return [x.split('/')[-1] for x in glob.glob(brif_regex)]
+
+
+def is_bridge_member(nic):
+    """Check if a given nic is a member of a bridge."""
+    for bridge in get_bridges():
+        if nic in get_bridge_nics(bridge):
+            return True
+
+    return False

=== added file 'hooks/charmhelpers/core/fstab.py'
--- hooks/charmhelpers/core/fstab.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/fstab.py	2014-12-11 14:18:46 +0000
@@ -0,0 +1,118 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+__author__ = 'Jorge Niedbalski R. <[e-mail]>'
+
+import io
+import os
+
+
+class Fstab(io.FileIO):
+    """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 = int(d)
+            self.p = int(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
+        super(Fstab, self).__init__(self._path, 'rb+')
+
+    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():
+            line = line.decode('us-ascii')
+            try:
+                if line.strip() and 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').encode('us-ascii'))
+        self.truncate()
+        return entry
+
+    def remove_entry(self, entry):
+        self.seek(0)
+
+        lines = [l.decode('us-ascii') for l in 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).encode('us-ascii'))
+        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	2014-02-19 14:49:31 +0000
+++ hooks/charmhelpers/core/hookenv.py	2014-12-11 14:18:46 +0000
@@ -9,9 +9,14 @@
 import yaml
 import subprocess
 import sys
-import UserDict
 from subprocess import CalledProcessError
 
+import six
+if not six.PY3:
+    from UserDict import UserDict
+else:
+    from collections import UserDict
+
 CRITICAL = "CRITICAL"
 ERROR = "ERROR"
 WARNING = "WARNING"
@@ -25,7 +30,7 @@
 def cached(func):
     """Cache return values for multiple executions of func + args
 
-    For example:
+    For example::
 
         @cached
         def unit_get(attribute):
@@ -67,12 +72,12 @@
     subprocess.call(command)
 
 
-class Serializable(UserDict.IterableUserDict):
+class Serializable(UserDict):
     """Wrapper, an object that can be serialized to yaml or json"""
 
     def __init__(self, obj):
         # wrap the object
-        UserDict.IterableUserDict.__init__(self)
+        UserDict.__init__(self)
         self.data = obj
 
     def __getattr__(self, attr):
@@ -155,6 +160,127 @@
     return os.path.basename(sys.argv[0])
 
 
+class Config(dict):
+    """A dictionary representation of the charm's config.yaml, with some
+    extra features:
+
+    - See which values in the dictionary have changed since the previous hook.
+    - For values that have changed, see what the previous value was.
+    - Store arbitrary data for use in a later hook.
+
+    NOTE: Do not instantiate this object directly - instead call
+    ``hookenv.config()``, which will return an instance of :class:`Config`.
+
+    Example usage::
+
+        >>> # inside a hook
+        >>> from charmhelpers.core import hookenv
+        >>> config = hookenv.config()
+        >>> config['foo']
+        'bar'
+        >>> # store a new key/value for later use
+        >>> config['mykey'] = 'myval'
+
+
+        >>> # 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'
+
+    """
+    CONFIG_FILE_NAME = '.juju-persistent-config'
+
+    def __init__(self, *args, **kw):
+        super(Config, self).__init__(*args, **kw)
+        self.implicit_save = True
+        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 __getitem__(self, key):
+        """For regular dict lookups, check the current juju config first,
+        then the previous (saved) copy. This ensures that user-saved values
+        will be returned by a dict lookup.
+
+        """
+        try:
+            return dict.__getitem__(self, key)
+        except KeyError:
+            return (self._prev_dict or {})[key]
+
+    def keys(self):
+        prev_keys = []
+        if self._prev_dict is not None:
+            prev_keys = self._prev_dict.keys()
+        return list(set(prev_keys + list(dict.keys(self))))
+
+    def load_previous(self, path=None):
+        """Load previous copy of config from disk.
+
+        In normal usage you don't need to call this method directly - it
+        is called automatically at object initialization.
+
+        :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 current value for this key is different from
+        the previous value.
+
+        """
+        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.
+
+        If the charm is using the :mod:`Services Framework <services.base>`
+        or :meth:'@hook <Hooks.hook>' decorator, this
+        is called automatically at the end of successful hook execution.
+        Otherwise, it should be called directly by user code.
+
+        To disable automatic saves, set ``implicit_save=False`` on this
+        instance.
+
+        """
+        if self._prev_dict:
+            for k, v in six.iteritems(self._prev_dict):
+                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"""
@@ -163,7 +289,11 @@
         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).decode('UTF-8'))
+        if scope is not None:
+            return config_data
+        return Config(config_data)
     except ValueError:
         return None
 
@@ -179,21 +309,22 @@
     if unit:
         _args.append(unit)
     try:
-        return json.loads(subprocess.check_output(_args))
+        return json.loads(subprocess.check_output(_args).decode('UTF-8'))
     except ValueError:
         return None
-    except CalledProcessError, e:
+    except CalledProcessError as e:
         if e.returncode == 2:
             return None
         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))
-    for k, v in (relation_settings.items() + kwargs.items()):
+    for k, v in (list(relation_settings.items()) + list(kwargs.items())):
         if v is None:
             relation_cmd_line.append('{}='.format(k))
         else:
@@ -210,7 +341,8 @@
     relid_cmd_line = ['relation-ids', '--format=json']
     if reltype is not None:
         relid_cmd_line.append(reltype)
-        return json.loads(subprocess.check_output(relid_cmd_line)) or []
+        return json.loads(
+            subprocess.check_output(relid_cmd_line).decode('UTF-8')) or []
     return []
 
 
@@ -221,7 +353,8 @@
     units_cmd_line = ['relation-list', '--format=json']
     if relid is not None:
         units_cmd_line.extend(('-r', relid))
-    return json.loads(subprocess.check_output(units_cmd_line)) or []
+    return json.loads(
+        subprocess.check_output(units_cmd_line).decode('UTF-8')) or []
 
 
 @cached
@@ -330,7 +463,7 @@
     """Get the unit ID for the remote unit"""
     _args = ['unit-get', '--format=json', attribute]
     try:
-        return json.loads(subprocess.check_output(_args))
+        return json.loads(subprocess.check_output(_args).decode('UTF-8'))
     except ValueError:
         return None
 
@@ -348,27 +481,29 @@
 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
             hooks.execute(sys.argv)
     """
 
-    def __init__(self):
+    def __init__(self, config_save=True):
         super(Hooks, self).__init__()
         self._hooks = {}
+        self._config_save = config_save
 
     def register(self, name, function):
         """Register a hook"""
@@ -379,6 +514,10 @@
         hook_name = os.path.basename(args[0])
         if hook_name in self._hooks:
             self._hooks[hook_name]()
+            if self._config_save:
+                cfg = config()
+                if cfg.implicit_save:
+                    cfg.save()
         else:
             raise UnregisteredHookError(hook_name)
 

=== modified file 'hooks/charmhelpers/core/host.py'
--- hooks/charmhelpers/core/host.py	2014-02-19 14:49:31 +0000
+++ hooks/charmhelpers/core/host.py	2014-12-11 14:18:46 +0000
@@ -6,16 +6,20 @@
 #  Matthew Wedgwood <[e-mail]>
 
 import os
+import re
 import pwd
 import grp
 import random
 import string
 import subprocess
 import hashlib
-
+from contextlib import contextmanager
 from collections import OrderedDict
 
-from hookenv import log
+import six
+
+from .hookenv import log
+from .fstab import Fstab
 
 
 def service_start(service_name):
@@ -34,7 +38,8 @@
 
 
 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 +55,9 @@
 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).decode('UTF-8')
     except subprocess.CalledProcessError:
         return False
     else:
@@ -60,6 +67,18 @@
             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).decode('UTF-8')
+    except subprocess.CalledProcessError as e:
+        return 'unrecognized service' not in e.output
+    else:
+        return True
+
+
 def adduser(username, password=None, shell='/bin/bash', system_user=False):
     """Add a user to the system"""
     try:
@@ -101,7 +120,7 @@
     cmd.append(from_path)
     cmd.append(to_path)
     log(" ".join(cmd))
-    return subprocess.check_output(cmd).strip()
+    return subprocess.check_output(cmd).decode('UTF-8').strip()
 
 
 def symlink(source, destination):
@@ -116,7 +135,7 @@
     subprocess.check_call(cmd)
 
 
-def mkdir(path, owner='root', group='root', perms=0555, force=False):
+def mkdir(path, owner='root', group='root', perms=0o555, force=False):
     """Create a directory"""
     log("Making dir {} {}:{} {:o}".format(path, owner, group,
                                           perms))
@@ -132,7 +151,7 @@
     os.chown(realpath, uid, gid)
 
 
-def write_file(path, content, owner='root', group='root', perms=0444):
+def write_file(path, content, owner='root', group='root', perms=0o444):
     """Create or overwrite a file with the contents of a string"""
     log("Writing file {} {}:{} {:o}".format(path, owner, group, perms))
     uid = pwd.getpwnam(owner).pw_uid
@@ -143,7 +162,19 @@
         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:
@@ -151,12 +182,12 @@
     cmd_args.extend([device, mountpoint])
     try:
         subprocess.check_output(cmd_args)
-    except subprocess.CalledProcessError, e:
+    except subprocess.CalledProcessError as 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
 
 
@@ -165,12 +196,12 @@
     cmd_args = ['umount', mountpoint]
     try:
         subprocess.check_output(cmd_args)
-    except subprocess.CalledProcessError, e:
+    except subprocess.CalledProcessError as e:
         log('Error unmounting {}\n{}'.format(mountpoint, e.output))
         return False
+
     if persist:
-        # TODO: update fstab
-        pass
+        return fstab_remove(mountpoint)
     return True
 
 
@@ -183,27 +214,52 @@
     return system_mounts
 
 
-def file_hash(path):
-    """Generate a md5 hash of the contents of 'path' or None if not found """
+def file_hash(path, hash_type='md5'):
+    """
+    Generate a hash checksum of the contents of 'path' or None if not found.
+
+    :param str hash_type: Any hash alrgorithm supported by :mod:`hashlib`,
+                          such as md5, sha1, sha256, sha512, etc.
+    """
     if os.path.exists(path):
-        h = hashlib.md5()
-        with open(path, 'r') as source:
-            h.update(source.read())  # IGNORE:E1101 - it does have update
+        h = getattr(hashlib, hash_type)()
+        with open(path, 'rb') as source:
+            h.update(source.read())
         return h.hexdigest()
     else:
         return None
 
 
+def check_hash(path, checksum, hash_type='md5'):
+    """
+    Validate a file using a cryptographic checksum.
+
+    :param str checksum: Value of the checksum used to validate the file.
+    :param str hash_type: Hash algorithm used to generate `checksum`.
+        Can be any hash alrgorithm supported by :mod:`hashlib`,
+        such as md5, sha1, sha256, sha512, etc.
+    :raises ChecksumError: If the file fails the checksum
+
+    """
+    actual_checksum = file_hash(path, hash_type)
+    if checksum != actual_checksum:
+        raise ChecksumError("'%s' != '%s'" % (checksum, actual_checksum))
+
+
+class ChecksumError(ValueError):
+    pass
+
+
 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
@@ -246,7 +302,7 @@
     if length is None:
         length = random.choice(range(35, 45))
     alphanumeric_chars = [
-        l for l in (string.letters + string.digits)
+        l for l in (string.ascii_letters + string.digits)
         if l not in 'l0QD1vAEIOUaeiou']
     random_chars = [
         random.choice(alphanumeric_chars) for _ in range(length)]
@@ -255,18 +311,24 @@
 
 def list_nics(nic_type):
     '''Return a list of nics of given type(s)'''
-    if isinstance(nic_type, basestring):
+    if isinstance(nic_type, six.string_types):
         int_types = [nic_type]
     else:
         int_types = nic_type
     interfaces = []
     for int_type in int_types:
         cmd = ['ip', 'addr', 'show', 'label', int_type + '*']
-        ip_output = subprocess.check_output(cmd).split('\n')
+        ip_output = subprocess.check_output(cmd).decode('UTF-8').split('\n')
         ip_output = (line for line in ip_output if line)
         for line in ip_output:
             if line.split()[1].startswith(int_type):
-                interfaces.append(line.split()[1].replace(":", ""))
+                matched = re.search('.*: (bond[0-9]+\.[0-9]+)@.*', line)
+                if matched:
+                    interface = matched.groups()[0]
+                else:
+                    interface = line.split()[1].replace(":", "")
+                interfaces.append(interface)
+
     return interfaces
 
 
@@ -278,7 +340,7 @@
 
 def get_nic_mtu(nic):
     cmd = ['ip', 'addr', 'show', nic]
-    ip_output = subprocess.check_output(cmd).split('\n')
+    ip_output = subprocess.check_output(cmd).decode('UTF-8').split('\n')
     mtu = ""
     for line in ip_output:
         words = line.split()
@@ -289,9 +351,46 @@
 
 def get_nic_hwaddr(nic):
     cmd = ['ip', '-o', '-0', 'addr', 'show', nic]
-    ip_output = subprocess.check_output(cmd)
+    ip_output = subprocess.check_output(cmd).decode('UTF-8')
     hwaddr = ""
     words = ip_output.split()
     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
+    from charmhelpers.fetch import apt_cache
+    if not pkgcache:
+        pkgcache = apt_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	2014-12-11 14:18:46 +0000
@@ -0,0 +1,2 @@
+from .base import *  # NOQA
+from .helpers import *  # NOQA

=== 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	2014-12-11 14:18:46 +0000
@@ -0,0 +1,313 @@
+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.
+
+        Service definitions are dicts in the following formats (all keys except
+        'service' are optional)::
+
+            {
+                "service": <service name>,
+                "required_data": <list of required data contexts>,
+                "provided_data": <list of provided 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 'provided_data' list should contain relation data providers, most likely
+        a subclass of :class:`charmhelpers.core.services.helpers.RelationContext`,
+        that will indicate a set of data to set on a given relation.
+
+        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()
+        cfg = hookenv.config()
+        if cfg.implicit_save:
+            cfg.save()
+
+    def provide_data(self):
+        """
+        Set the relation data for each provider in the ``provided_data`` list.
+
+        A provider must have a `name` attribute, which indicates which relation
+        to set data on, and a `provide_data()` method, which returns a dict of
+        data to set.
+        """
+        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()
+                    _ready = provider._is_ready(data) if hasattr(provider, '_is_ready') else data
+                    if _ready:
+                        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	2014-12-11 14:18:46 +0000
@@ -0,0 +1,243 @@
+import os
+import yaml
+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 relation :attr:`name`,
+    to prevent potential naming conflicts.
+
+    :param str name: Override the relation :attr:`name`, since it can vary from charm to charm
+    :param list additional_required_keys: Extend the list of :attr:`required_keys`
+    """
+    name = None
+    interface = None
+    required_keys = []
+
+    def __init__(self, name=None, additional_required_keys=None):
+        if name is not None:
+            self.name = name
+        if additional_required_keys is not None:
+            self.required_keys.extend(additional_required_keys)
+        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 MysqlRelation(RelationContext):
+    """
+    Relation context for the `mysql` interface.
+
+    :param str name: Override the relation :attr:`name`, since it can vary from charm to charm
+    :param list additional_required_keys: Extend the list of :attr:`required_keys`
+    """
+    name = 'db'
+    interface = 'mysql'
+    required_keys = ['host', 'user', 'password', 'database']
+
+
+class HttpRelation(RelationContext):
+    """
+    Relation context for the `http` interface.
+
+    :param str name: Override the relation :attr:`name`, since it can vary from charm to charm
+    :param list additional_required_keys: Extend the list of :attr:`required_keys`
+    """
+    name = 'website'
+    interface = 'http'
+    required_keys = ['host', 'port']
+
+    def provide_data(self):
+        return {
+            'host': hookenv.unit_get('private-address'),
+            'port': 80,
+        }
+
+
+class RequiredConfig(dict):
+    """
+    Data context that loads config options with one or more mandatory options.
+
+    Once the required options have been changed from their default values, all
+    config options will be available, namespaced under `config` to prevent
+    potential naming conflicts (for example, between a config option and a
+    relation property).
+
+    :param list *args: List of options that must be changed from their default values.
+    """
+
+    def __init__(self, *args):
+        self.required_options = args
+        self['config'] = hookenv.config()
+        with open(os.path.join(hookenv.charm_dir(), 'config.yaml')) as fp:
+            self.config = yaml.load(fp).get('options', {})
+
+    def __bool__(self):
+        for option in self.required_options:
+            if option not in self['config']:
+                return False
+            current_value = self['config'][option]
+            default_value = self.config[option].get('default')
+            if current_value == default_value:
+                return False
+            if current_value in (None, '') and default_value in (None, ''):
+                return False
+        return True
+
+    def __nonzero__(self):
+        return self.__bool__()
+
+
+class StoredContext(dict):
+    """
+    A data context that always returns the data that it was first created with.
+
+    This is useful to do a one-time generation of things like passwords, that
+    will thereafter use the same value that was originally generated, instead
+    of generating a new value each time it is run.
+    """
+    def __init__(self, file_name, config_data):
+        """
+        If the file exists, populate `self` with the data from the file.
+        Otherwise, populate with the given data and persist it to the file.
+        """
+        if os.path.exists(file_name):
+            self.update(self.read_context(file_name))
+        else:
+            self.store_context(file_name, config_data)
+            self.update(config_data)
+
+    def store_context(self, file_name, config_data):
+        if not os.path.isabs(file_name):
+            file_name = os.path.join(hookenv.charm_dir(), file_name)
+        with open(file_name, 'w') as file_stream:
+            os.fchmod(file_stream.fileno(), 0o600)
+            yaml.dump(config_data, file_stream)
+
+    def read_context(self, file_name):
+        if not os.path.isabs(file_name):
+            file_name = os.path.join(hookenv.charm_dir(), file_name)
+        with open(file_name, 'r') as file_stream:
+            data = yaml.load(file_stream)
+            if not data:
+                raise OSError("%s is empty" % file_name)
+            return data
+
+
+class TemplateCallback(ManagerCallback):
+    """
+    Callback class that will render a Jinja2 template, for use as a ready
+    action.
+
+    :param str source: The template source file, relative to
+    `$CHARM_DIR/templates`
+
+    :param str target: The target to write the rendered template to
+    :param str owner: The owner of the rendered file
+    :param str group: The group of the rendered file
+    :param int perms: The permissions of the rendered file
+    """
+    def __init__(self, source, target,
+                 owner='root', group='root', perms=0o444):
+        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/sysctl.py'
--- hooks/charmhelpers/core/sysctl.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/sysctl.py	2014-12-11 14:18:46 +0000
@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+__author__ = 'Jorge Niedbalski R. <[e-mail]>'
+
+import yaml
+
+from subprocess import check_call
+
+from charmhelpers.core.hookenv import (
+    log,
+    DEBUG,
+)
+
+
+def create(sysctl_dict, sysctl_file):
+    """Creates a sysctl.conf file from a YAML associative array
+
+    :param sysctl_dict: a dict of sysctl options eg { 'kernel.max_pid': 1337 }
+    :type sysctl_dict: dict
+    :param sysctl_file: path to the sysctl file to be saved
+    :type sysctl_file: str or unicode
+    :returns: None
+    """
+    sysctl_dict = yaml.load(sysctl_dict)
+
+    with open(sysctl_file, "w") as fd:
+        for key, value in sysctl_dict.items():
+            fd.write("{}={}\n".format(key, value))
+
+    log("Updating sysctl_file: %s values: %s" % (sysctl_file, sysctl_dict),
+        level=DEBUG)
+
+    check_call(["sysctl", "-p", sysctl_file])

=== added file 'hooks/charmhelpers/core/templating.py'
--- hooks/charmhelpers/core/templating.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/templating.py	2014-12-11 14:18:46 +0000
@@ -0,0 +1,52 @@
+import os
+
+from charmhelpers.core import host
+from charmhelpers.core import hookenv
+
+
+def render(source, target, context, owner='root', group='root',
+           perms=0o444, 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)

=== modified file 'hooks/charmhelpers/fetch/__init__.py'
--- hooks/charmhelpers/fetch/__init__.py	2014-05-08 10:22:43 +0000
+++ hooks/charmhelpers/fetch/__init__.py	2014-12-11 14:18:46 +0000
@@ -1,20 +1,24 @@
 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 apt_pkg
 import os
 
+import six
+if six.PY3:
+    from urllib.parse import urlparse, urlunparse
+else:
+    from urlparse import urlparse, urlunparse
+
+
 CLOUD_ARCHIVE = """# Ubuntu Cloud Archive
 deb http://ubuntu-cloud.archive.canonical.com/ubuntu {} main
 """
@@ -54,13 +58,69 @@
     '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',
+    'charmhelpers.fetch.giturl.GitUrlFetchHandler',
+)
+
+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"""
-    apt_pkg.init()
-    cache = apt_pkg.Cache()
+    cache = apt_cache()
     _pkgs = []
     for package in packages:
         try:
@@ -73,6 +133,16 @@
     return _pkgs
 
 
+def apt_cache(in_memory=True):
+    """Build and return an apt cache"""
+    import apt_pkg
+    apt_pkg.init()
+    if in_memory:
+        apt_pkg.config.set("Dir::Cache::pkgcache", "")
+        apt_pkg.config.set("Dir::Cache::srcpkgcache", "")
+    return apt_pkg.Cache()
+
+
 def apt_install(packages, options=None, fatal=False):
     """Install one or more packages"""
     if options is None:
@@ -81,20 +151,13 @@
     cmd = ['apt-get', '--assume-yes']
     cmd.extend(options)
     cmd.append('install')
-    if isinstance(packages, basestring):
+    if isinstance(packages, six.string_types):
         cmd.append(packages)
     else:
         cmd.extend(packages)
     log("Installing {} with options: {}".format(packages,
                                                 options))
-    env = os.environ.copy()
-    if 'DEBIAN_FRONTEND' not in env:
-        env['DEBIAN_FRONTEND'] = 'noninteractive'
-
-    if fatal:
-        subprocess.check_call(cmd, env=env)
-    else:
-        subprocess.call(cmd, env=env)
+    _run_apt_command(cmd, fatal)
 
 
 def apt_upgrade(options=None, fatal=False, dist=False):
@@ -109,48 +172,35 @@
     else:
         cmd.append('upgrade')
     log("Upgrading with options: {}".format(options))
-
-    env = os.environ.copy()
-    if 'DEBIAN_FRONTEND' not in env:
-        env['DEBIAN_FRONTEND'] = 'noninteractive'
-
-    if fatal:
-        subprocess.check_call(cmd, env=env)
-    else:
-        subprocess.call(cmd, env=env)
+    _run_apt_command(cmd, fatal)
 
 
 def apt_update(fatal=False):
     """Update local apt cache"""
     cmd = ['apt-get', 'update']
-    if fatal:
-        subprocess.check_call(cmd)
-    else:
-        subprocess.call(cmd)
+    _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):
+    if isinstance(packages, six.string_types):
         cmd.append(packages)
     else:
         cmd.extend(packages)
     log("Purging {}".format(packages))
-    if fatal:
-        subprocess.check_call(cmd)
-    else:
-        subprocess.call(cmd)
+    _run_apt_command(cmd, fatal)
 
 
 def apt_hold(packages, fatal=False):
     """Hold one or more packages"""
     cmd = ['apt-mark', 'hold']
-    if isinstance(packages, basestring):
+    if isinstance(packages, six.string_types):
         cmd.append(packages)
     else:
         cmd.extend(packages)
     log("Holding {}".format(packages))
+
     if fatal:
         subprocess.check_call(cmd)
     else:
@@ -158,6 +208,29 @@
 
 
 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'
+        'distro' may be used as a noop
+
+    @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
@@ -182,76 +255,98 @@
         release = lsb_release()['DISTRIB_CODENAME']
         with open('/etc/apt/sources.list.d/proposed.list', 'w') as apt:
             apt.write(PROPOSED_POCKET.format(release))
+    elif source == 'distro':
+        pass
+    else:
+        log("Unknown source: {!r}".format(source))
+
     if key:
-        subprocess.check_call(['apt-key', 'adv', '--keyserver',
-                               'hkp://keyserver.ubuntu.com:80', '--recv',
-                               key])
-
-
-class SourceConfigError(Exception):
-    pass
+        if '-----BEGIN PGP PUBLIC KEY BLOCK-----' in key:
+            with NamedTemporaryFile('w+') 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
+    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:
+        install_sources: |
           - "ppa:foo"
           - "http://example.com/repo precise main"
-        install_keys:
+        install_keys: |
           - null
           - "a1b2c3d4"
 
     Note that 'null' (a.k.a. None) should not be quoted.
     """
-    sources = safe_load(config(sources_var))
-    keys = config(keys_var)
-    if keys is not None:
-        keys = safe_load(keys)
-    if isinstance(sources, basestring) and (
-            keys is None or isinstance(keys, basestring)):
-        add_source(sources, keys)
+    sources = safe_load((config(sources_var) or '').strip()) or []
+    keys = safe_load((config(keys_var) or '').strip()) or None
+
+    if isinstance(sources, six.string_types):
+        sources = [sources]
+
+    if keys is None:
+        for source in sources:
+            add_source(source, None)
     else:
-        if not len(sources) == len(keys):
-            msg = 'Install sources and keys lists are different lengths'
-            raise SourceConfigError(msg)
-        for src_num in range(len(sources)):
-            add_source(sources[src_num], keys[src_num])
+        if isinstance(keys, six.string_types):
+            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)
 
-# 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',
-)
-
-
-class UnhandledSource(Exception):
-    pass
-
-
-def install_remote(source):
+
+def install_remote(source, *args, **kwargs):
     """
     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"""
+    Schemes supported are based on this modules submodules.
+    Options supported are submodule-specific.
+    Additional arguments are passed through to the submodule.
+
+    For example::
+
+        dest = install_remote('http://example.com/archive.tgz',
+                              checksum='deadbeef',
+                              hash_type='sha1')
+
+    This will download `archive.tgz`, validate it using SHA1 and, if
+    the file is ok, extract it and return the directory in which it
+    was extracted.  If the checksum fails, it will raise
+    :class:`charmhelpers.core.host.ChecksumError`.
+    """
     # 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)
+            installed_to = handler.install(source, *args, **kwargs)
         except UnhandledSource:
             pass
     if not installed_to:
@@ -265,30 +360,6 @@
     return install_remote(source)
 
 
-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 plugins(fetch_handlers=None):
     if not fetch_handlers:
         fetch_handlers = FETCH_HANDLERS
@@ -306,3 +377,40 @@
             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 as 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)

=== modified file 'hooks/charmhelpers/fetch/archiveurl.py'
--- hooks/charmhelpers/fetch/archiveurl.py	2014-04-17 10:53:00 +0000
+++ hooks/charmhelpers/fetch/archiveurl.py	2014-12-11 14:18:46 +0000
@@ -1,6 +1,23 @@
 import os
-import urllib2
-import urlparse
+import hashlib
+import re
+
+import six
+if six.PY3:
+    from urllib.request import (
+        build_opener, install_opener, urlopen, urlretrieve,
+        HTTPPasswordMgrWithDefaultRealm, HTTPBasicAuthHandler,
+    )
+    from urllib.parse import urlparse, urlunparse, parse_qs
+    from urllib.error import URLError
+else:
+    from urllib import urlretrieve
+    from urllib2 import (
+        build_opener, install_opener, urlopen,
+        HTTPPasswordMgrWithDefaultRealm, HTTPBasicAuthHandler,
+        URLError
+    )
+    from urlparse import urlparse, urlunparse, parse_qs
 
 from charmhelpers.fetch import (
     BaseFetchHandler,
@@ -10,11 +27,37 @@
     get_archive_handler,
     extract,
 )
-from charmhelpers.core.host import mkdir
+from charmhelpers.core.host import mkdir, check_hash
+
+
+def splituser(host):
+    '''urllib.splituser(), but six's support of this seems broken'''
+    _userprog = re.compile('^(.*)@(.*)$')
+    match = _userprog.match(host)
+    if match:
+        return match.group(1, 2)
+    return None, host
+
+
+def splitpasswd(user):
+    '''urllib.splitpasswd(), but six's support of this is missing'''
+    _passwdprog = re.compile('^([^:]*):(.*)$', re.S)
+    match = _passwdprog.match(user)
+    if match:
+        return match.group(1, 2)
+    return user, None
 
 
 class ArchiveUrlFetchHandler(BaseFetchHandler):
-    """Handler for archives via generic URLs"""
+    """
+    Handler to download archive files from arbitrary URLs.
+
+    Can fetch from http, https, ftp, and file URLs.
+
+    Can install either tarballs (.tar, .tgz, .tbz2, etc) or zip files.
+
+    Installs the contents of the archive in $CHARM_DIR/fetched/.
+    """
     def can_handle(self, source):
         url_parts = self.parse_url(source)
         if url_parts.scheme not in ('http', 'https', 'ftp', 'file'):
@@ -24,22 +67,28 @@
         return False
 
     def download(self, source, dest):
+        """
+        Download an archive file.
+
+        :param str source: URL pointing to an archive file.
+        :param str dest: Local path location to download archive file to.
+        """
         # propogate all exceptions
         # URLError, OSError, etc
-        proto, netloc, path, params, query, fragment = urlparse.urlparse(source)
+        proto, netloc, path, params, query, fragment = urlparse(source)
         if proto in ('http', 'https'):
-            auth, barehost = urllib2.splituser(netloc)
+            auth, barehost = splituser(netloc)
             if auth is not None:
-                source = urlparse.urlunparse((proto, barehost, path, params, query, fragment))
-                username, password = urllib2.splitpasswd(auth)
-                passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
+                source = urlunparse((proto, barehost, path, params, query, fragment))
+                username, password = splitpasswd(auth)
+                passman = 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)
+                authhandler = HTTPBasicAuthHandler(passman)
+                opener = build_opener(authhandler)
+                install_opener(opener)
+        response = urlopen(source)
         try:
             with open(dest, 'w') as dest_file:
                 dest_file.write(response.read())
@@ -48,16 +97,49 @@
                 os.unlink(dest)
             raise e
 
-    def install(self, source):
+    # Mandatory file validation via Sha1 or MD5 hashing.
+    def download_and_validate(self, url, hashsum, validate="sha1"):
+        tempfile, headers = urlretrieve(url)
+        check_hash(tempfile, hashsum, validate)
+        return tempfile
+
+    def install(self, source, dest=None, checksum=None, hash_type='sha1'):
+        """
+        Download and install an archive file, with optional checksum validation.
+
+        The checksum can also be given on the `source` URL's fragment.
+        For example::
+
+            handler.install('http://example.com/file.tgz#sha1=deadbeef')
+
+        :param str source: URL pointing to an archive file.
+        :param str dest: Local destination path to install to. If not given,
+            installs to `$CHARM_DIR/archives/archive_file_name`.
+        :param str checksum: If given, validate the archive file after download.
+        :param str hash_type: Algorithm used to generate `checksum`.
+            Can be any hash alrgorithm supported by :mod:`hashlib`,
+            such as md5, sha1, sha256, sha512, etc.
+
+        """
         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)
+            mkdir(dest_dir, perms=0o755)
         dld_file = os.path.join(dest_dir, os.path.basename(url_parts.path))
         try:
             self.download(source, dld_file)
-        except urllib2.URLError as e:
+        except URLError as e:
             raise UnhandledSource(e.reason)
         except OSError as e:
             raise UnhandledSource(e.strerror)
-        return extract(dld_file)
+        options = parse_qs(url_parts.fragment)
+        for key, value in options.items():
+            if not six.PY3:
+                algorithms = hashlib.algorithms
+            else:
+                algorithms = hashlib.algorithms_available
+            if key in algorithms:
+                check_hash(dld_file, value, key)
+        if checksum:
+            check_hash(dld_file, checksum, hash_type)
+        return extract(dld_file, dest)

=== modified file 'hooks/charmhelpers/fetch/bzrurl.py'
--- hooks/charmhelpers/fetch/bzrurl.py	2014-02-19 14:49:31 +0000
+++ hooks/charmhelpers/fetch/bzrurl.py	2014-12-11 14:18:46 +0000
@@ -5,6 +5,10 @@
 )
 from charmhelpers.core.host import mkdir
 
+import six
+if six.PY3:
+    raise ImportError('bzrlib does not support Python3')
+
 try:
     from bzrlib.branch import Branch
 except ImportError:
@@ -39,9 +43,10 @@
     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)
+        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)
+            mkdir(dest_dir, perms=0o755)
         try:
             self.branch(source, dest_dir)
         except OSError as e:

=== added file 'hooks/charmhelpers/fetch/giturl.py'
--- hooks/charmhelpers/fetch/giturl.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/fetch/giturl.py	2014-12-11 14:18:46 +0000
@@ -0,0 +1,48 @@
+import os
+from charmhelpers.fetch import (
+    BaseFetchHandler,
+    UnhandledSource
+)
+from charmhelpers.core.host import mkdir
+
+import six
+if six.PY3:
+    raise ImportError('GitPython does not support Python 3')
+
+try:
+    from git import Repo
+except ImportError:
+    from charmhelpers.fetch import apt_install
+    apt_install("python-git")
+    from git import Repo
+
+
+class GitUrlFetchHandler(BaseFetchHandler):
+    """Handler for git branches via generic and github URLs"""
+    def can_handle(self, source):
+        url_parts = self.parse_url(source)
+        # TODO (mattyw) no support for ssh git@ yet
+        if url_parts.scheme not in ('http', 'https', 'git'):
+            return False
+        else:
+            return True
+
+    def clone(self, source, dest, branch):
+        if not self.can_handle(source):
+            raise UnhandledSource("Cannot handle {}".format(source))
+
+        repo = Repo.clone_from(source, dest)
+        repo.git.checkout(branch)
+
+    def install(self, source, branch="master"):
+        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=0o755)
+        try:
+            self.clone(source, dest_dir, branch)
+        except OSError as e:
+            raise UnhandledSource(e.strerror)
+        return dest_dir

=== modified file 'hooks/common.py'
--- hooks/common.py	2014-03-04 17:28:10 +0000
+++ hooks/common.py	2014-12-11 14:18:46 +0000
@@ -84,6 +84,8 @@
 
 def grant_exists(db_name, db_user, remote_ip):
     cursor = get_db_cursor()
+    priv_string = "GRANT ALL PRIVILEGES ON `{}`.* " \
+                  "TO '{}'@'{}'".format(db_name, db_user, remote_ip)
     try:
         cursor.execute("SHOW GRANTS for '{}'@'{}'".format(db_user,
                                                           remote_ip))
@@ -93,7 +95,7 @@
         return False
     finally:
         cursor.close()
-    return "GRANT ALL PRIVILEGES ON `{}`".format(db_name) in grants
+    return priv_string in grants
 
 
 def create_grant(db_name, db_user,

=== modified file 'hooks/config-changed'
--- hooks/config-changed	2014-05-09 11:17:36 +0000
+++ hooks/config-changed	2014-12-11 14:18:46 +0000
@@ -12,7 +12,8 @@
 from string import upper
 from charmhelpers.fetch import (
     add_source,
-    apt_update
+    apt_update,
+    apt_install
 )
 from charmhelpers.core.hookenv import relations_of_type
 
@@ -71,6 +72,9 @@
                 return '%s%s' % (mtot, upper(modifier[0]))
 
 
+if configs['prefer-ipv6']:
+    utils.check_ipv6_compatibility()
+
 # There is preliminary code for mariadb, but switching
 # from mariadb -> mysql fails badly, so it is disabled for now.
 valid_flavors = ['distro','percona']
@@ -116,7 +120,7 @@
 
 if len(remove_pkgs):
     check_call(['apt-get','-y','remove'] + remove_pkgs)
-check_call(['apt-get','-y','install','-qq',package])
+apt_install(package)
 
 # smart-calc stuff in the configs
 dataset_bytes = human_to_bytes(configs['dataset-size'])
@@ -171,6 +175,11 @@
 else:
     configs['max-connections'] = 'max_connections = %s' % configs['max-connections']
 
+if configs['prefer-ipv6']:
+    configs['bind-address'] = '::' 
+else:
+    configs['bind-address'] = '0.0.0.0'
+
 template="""
 ######################################
 #
@@ -234,7 +243,7 @@
 #
 # Instead of skip-networking the default is now to listen only on
 # localhost which is more compatible and is not less secure.
-bind-address		= 0.0.0.0
+bind-address		= %(bind-address)s
 #
 # * Fine Tuning
 #

=== modified file 'hooks/ha_relations.py'
--- hooks/ha_relations.py	2014-03-04 17:28:10 +0000
+++ hooks/ha_relations.py	2014-12-11 14:18:46 +0000
@@ -42,10 +42,18 @@
 
         block_storage = 'ceph'
 
+        if utils.config_get('prefer-ipv6'):
+            res_mysql_vip = 'ocf:heartbeat:IPv6addr'
+            vip_params = 'ipv6addr'
+            vip_cidr = '64'
+        else:
+            res_mysql_vip = 'ocf:heartbeat:IPaddr2'
+            vip_params = 'ip'
+
         resources = {
             'res_mysql_rbd': 'ocf:ceph:rbd',
             'res_mysql_fs': 'ocf:heartbeat:Filesystem',
-            'res_mysql_vip': 'ocf:heartbeat:IPaddr2',
+            'res_mysql_vip': res_mysql_vip,
             'res_mysqld': 'upstart:mysql'}
 
         rbd_name = utils.config_get('rbd-name')
@@ -57,8 +65,8 @@
             'res_mysql_fs': 'params device="/dev/rbd/%s/%s" directory="%s" '
                             'fstype="ext4" op start start-delay="10s"' %
                             (POOL_NAME, rbd_name, DATA_SRC_DST),
-            'res_mysql_vip': 'params ip="%s" cidr_netmask="%s" nic="%s"' %
-                             (vip, vip_cidr, vip_iface),
+            'res_mysql_vip': 'params "%s"="%s" cidr_netmask="%s" nic="%s"' %
+                             (vip_params, vip, vip_cidr, vip_iface),
             'res_mysqld': 'op start start-delay="5s" op monitor interval="5s"'}
 
         groups = {

=== modified file 'hooks/lib/ceph_utils.py'
--- hooks/lib/ceph_utils.py	2014-03-04 17:28:10 +0000
+++ hooks/lib/ceph_utils.py	2014-12-11 14:18:46 +0000
@@ -16,6 +16,10 @@
 import time
 import lib.utils as utils
 
+from charmhelpers.contrib.network.ip import (
+    format_ipv6_addr
+)
+
 KEYRING = '/etc/ceph/ceph.client.%s.keyring'
 KEYFILE = '/etc/ceph/ceph.client.%s.key'
 
@@ -163,8 +167,14 @@
     hosts = []
     for r_id in utils.relation_ids('ceph'):
         for unit in utils.relation_list(r_id):
-            hosts.append(utils.relation_get('private-address',
-                                            unit=unit, rid=r_id))
+            ceph_addr = \
+                utils.relation_get('ceph-public-address', rid=r_id,
+                                   unit=unit) or \
+                utils.relation_get('private-address', rid=r_id, unit=unit)
+            # We host is an ipv6 address we need to wrap it in []
+            ceph_addr = format_ipv6_addr(ceph_addr) or ceph_addr
+            hosts.append(ceph_addr)
+
     return hosts
 
 

=== modified file 'hooks/lib/utils.py'
--- hooks/lib/utils.py	2014-03-04 17:28:10 +0000
+++ hooks/lib/utils.py	2014-12-11 14:18:46 +0000
@@ -14,6 +14,9 @@
 import subprocess
 import socket
 import sys
+from charmhelpers.core.host import (
+    lsb_release
+)
 
 
 def do_hooks(hooks):
@@ -219,3 +222,9 @@
             if relation_get(key, rid=r_id, unit=unit):
                 return True
     return False
+
+
+def check_ipv6_compatibility():
+    if lsb_release()['DISTRIB_CODENAME'].lower() < "trusty":
+        raise Exception("IPv6 is not supported in charms for Ubuntu "
+                        "versions less than Trusty 14.04")

=== modified file 'hooks/monitors-relation-joined'
--- hooks/monitors-relation-joined	2012-07-12 21:58:36 +0000
+++ hooks/monitors-relation-joined	2014-12-11 14:18:46 +0000
@@ -3,5 +3,7 @@
 . hooks/monitors.common.bash
 echo "'${monitor_user}'@'${remote_addr}'" >> $revoke_todo
 $MYSQL -e "GRANT USAGE ON *.* TO '${monitor_user}'@'${remote_addr}'"
+# Won't be getting the real remote address from NRPE subordinate. Need to have NRPE tell the charm the remote address in the near future
+$MYSQL -e "GRANT USAGE ON *.* TO '${monitor_user}'@'%'"
 
 relation-set monitors="$(cat monitors.yaml)" target-id=${JUJU_UNIT_NAME//\//-} target-address=$(unit-get private-address)

=== modified file 'hooks/shared_db_relations.py'
--- hooks/shared_db_relations.py	2014-10-09 10:18:28 +0000
+++ hooks/shared_db_relations.py	2014-12-11 14:18:46 +0000
@@ -19,6 +19,10 @@
 import os
 import lib.utils as utils
 import lib.cluster_utils as cluster
+from charmhelpers.core import hookenv
+from charmhelpers.contrib.network.ip import (
+    get_ipv6_addr
+)
 
 LEADER_RES = 'res_mysql_vip'
 
@@ -33,14 +37,62 @@
                                                'json']))
 
 
+def unit_sorted(units):
+    """Return a sorted list of unit names."""
+    return sorted(
+        units, lambda a, b: cmp(int(a.split('/')[-1]), int(b.split('/')[-1])))
+
+
+def get_unit_addr(relid, unitid):
+    return hookenv.relation_get(attribute='private-address',
+                                unit=unitid,
+                                rid=relid)
+
+
 def shared_db_changed():
 
+    def get_allowed_units(database, username):
+        allowed_units = set()
+        for relid in hookenv.relation_ids('shared-db'):
+            for unit in hookenv.related_units(relid):
+                attr = "%s_%s" % (database, 'hostname')
+                hosts = hookenv.relation_get(attribute=attr, unit=unit,
+                                             rid=relid)
+                if not hosts:
+                    hosts = [hookenv.relation_get(attribute='private-address',
+                                                  unit=unit, rid=relid)]
+                else:
+                    # hostname can be json-encoded list of hostnames
+                    try:
+                        hosts = json.loads(hosts)
+                    except ValueError:
+                        pass
+
+                if not isinstance(hosts, list):
+                    hosts = [hosts]
+
+                if hosts:
+                    for host in hosts:
+                        utils.juju_log('INFO', "Checking host '%s' grant" %
+                                       (host))
+                        if grant_exists(database, username, host):
+                            if unit not in allowed_units:
+                                allowed_units.add(unit)
+                else:
+                    utils.juju_log('INFO', "No hosts found for grant check")
+
+        return allowed_units
+
     def configure_db(hostname,
                      database,
                      username):
         passwd_file = "/var/lib/mysql/mysql-{}.passwd".format(username)
         if hostname != local_hostname:
-            remote_ip = socket.gethostbyname(hostname)
+            try:
+                remote_ip = socket.gethostbyname(hostname)
+            except Exception:
+                # socket.gethostbyname doesn't support ipv6
+                remote_ip = hostname
         else:
             remote_ip = '127.0.0.1'
 
@@ -69,8 +121,12 @@
                        ' as this service unit is not the leader')
         return
 
+    if utils.config_get('prefer-ipv6'):
+        local_hostname = get_ipv6_addr(exc_list=[utils.config_get('vip')])[0]
+    else:
+        local_hostname = utils.unit_get('private-address')
+
     settings = relation_get()
-    local_hostname = utils.unit_get('private-address')
     singleset = set([
         'database',
         'username',
@@ -78,15 +134,33 @@
 
     if singleset.issubset(settings):
         # Process a single database configuration
-        password = configure_db(settings['hostname'],
-                                settings['database'],
-                                settings['username'])
+        hostname = settings['hostname']
+        database = settings['database']
+        username = settings['username']
+
+        # Hostname can be json-encoded list of hostnames
+        try:
+            hostname = json.loads(hostname)
+        except ValueError:
+            pass
+
+        if isinstance(hostname, list):
+            for host in hostname:
+                password = configure_db(host, database, username)
+        else:
+            password = configure_db(hostname, database, username)
+
+        allowed_units = " ".join(unit_sorted(get_allowed_units(database,
+                                                               username)))
+
         if not cluster.is_clustered():
             utils.relation_set(db_host=local_hostname,
-                               password=password)
+                               password=password,
+                               allowed_units=allowed_units)
         else:
             utils.relation_set(db_host=utils.config_get("vip"),
-                               password=password)
+                               password=password,
+                               allowed_units=allowed_units)
 
     else:
         # Process multiple database setup requests.
@@ -114,13 +188,29 @@
             if db not in databases:
                 databases[db] = {}
             databases[db][x] = v
+
         return_data = {}
         for db in databases:
             if singleset.issubset(databases[db]):
-                return_data['_'.join([db, 'password'])] = \
-                    configure_db(databases[db]['hostname'],
-                                 databases[db]['database'],
-                                 databases[db]['username'])
+                database = databases[db]['database']
+                hostname = databases[db]['hostname']
+                username = databases[db]['username']
+                try:
+                    hostname = json.loads(hostname)
+                except ValueError:
+                    hostname = hostname
+
+                if isinstance(hostname, list):
+                    for host in hostname:
+                        password = configure_db(host, database, username)
+                else:
+                    password = configure_db(hostname, database, username)
+
+                return_data['_'.join([db, 'password'])] = password
+                allowed_units = unit_sorted(get_allowed_units(database,
+                                                              username))
+                return_data['_'.join([db, 'allowed_units'])] = \
+                    " ".join(allowed_units)
         if len(return_data) > 0:
             utils.relation_set(**return_data)
         if not cluster.is_clustered():
@@ -128,6 +218,7 @@
         else:
             utils.relation_set(db_host=utils.config_get("vip"))
 
+
 hooks = {"shared-db-relation-changed": shared_db_changed}
 
 utils.do_hooks(hooks)