Merge lp:~stub/charms/trusty/cassandra/bug-1557769-update-charmhelpers into lp:charms/trusty/cassandra

[Stuart Bishop]

Fix Bug #1557769 by updating to a version of charmhelpers with a fixed unit_private_ip() function.

Without this, services on some providers will fail to restart after being upgraded to 1.25.4.

[Review Queue (review-queue)]

The results (PASS) are in and available here: http://juju-ci.vapour.ws:8080/job/charm-bundle-test-aws/3209/

review: Approve (automated testing)

[Review Queue (review-queue)]

The results (PASS) are in and available here: http://juju-ci.vapour.ws:8080/job/charm-bundle-test-lxc/3246/

review: Approve (automated testing)

[Adam Israel (aisrael)]

Hey Stub, this looks good to me. Thanks for the updates! +1

review: Approve

=== modified file 'Makefile'
--- Makefile	2016-02-26 16:47:03 +0000
+++ Makefile	2016-03-17 11:00:44 +0000
@@ -24,6 +24,13 @@
 # Only trusty supported, but xenial expected soon.
 SERIES := $(shell juju get-environment default-series)
 
+HOST_SERIES := $(shell lsb_release -sc)
+ifeq ($(HOST_SERIES),trusty)
+    PYVER := 3.4
+else
+    PYVER := 3.5
+endif
+
 
 # /!\ Ensure that errors early in pipes cause failures, rather than
 # overridden by the last stage of the pipe. cf. 'test.py | ts'
@@ -41,8 +48,8 @@
 
 SITE_PACKAGES=$(wildcard $(VENV3)/lib/python*/site-packages)
 
-PIP=.venv3/bin/pip3.4 -q
-NOSETESTS=.venv3/bin/nosetests-3.4 -sv
+PIP=.venv3/bin/pip$(PYVER) -q
+NOSETESTS=.venv3/bin/nosetests-3.4 -sv  # Yes, even with 3.5
 
 # Set pipefail so we can get sane error codes while tagging test output
 # with ts(1)
@@ -177,7 +184,7 @@
 	# Create a .pth so our tests can locate everything without
 	# sys.path hacks.
 	(echo ${CHARM_DIR}/hooks; echo ${CHARM_DIR}) \
-	    > ${VENV3}/lib/python3.4/site-packages/tests.pth
+	    > ${VENV3}/lib/python${PYVER}/site-packages/tests.pth
 
 	echo 'pip: ' `which pip`
 

=== modified file 'hooks/actions.py'
--- hooks/actions.py	2016-02-26 16:47:03 +0000
+++ hooks/actions.py	2016-03-17 11:00:44 +0000
@@ -298,7 +298,7 @@
             helpers.status_set('blocked',
                                'Invalid private_jre_url {}'.format(url))
             raise SystemExit(0)
-        helpers.status_set(hookenv.status_get(),
+        helpers.status_set(hookenv.status_get()[0],
                            'Downloading Oracle JRE')
         hookenv.log('Oracle JRE URL is {}'.format(url))
         urllib.request.urlretrieve(url, filename)
@@ -507,7 +507,7 @@
     # during a restart.
     storage = relations.StorageRelation()
     if storage.needs_remount():
-        helpers.status_set(hookenv.status_get(),
+        helpers.status_set(hookenv.status_get()[0],
                            'New mounts. Waiting for restart permission')
         return True
 
@@ -517,7 +517,7 @@
             hookenv.log('{} changed. Restart required.'.format(key))
     for key in RESTART_REQUIRED_KEYS:
         if config.changed(key):
-            helpers.status_set(hookenv.status_get(),
+            helpers.status_set(hookenv.status_get()[0],
                                'Config changes. '
                                'Waiting for restart permission.')
             return True
@@ -530,7 +530,7 @@
         # We don't care about the local node in the changes.
         changed.discard(hookenv.unit_private_ip())
         if changed:
-            helpers.status_set(hookenv.status_get(),
+            helpers.status_set(hookenv.status_get()[0],
                                'Updated seeds {!r}. '
                                'Waiting for restart permission.'
                                ''.format(new_seeds))
@@ -924,7 +924,7 @@
     # not already active. We don't do this unconditionally, as the charm
     # may be active but doing stuff, like active but waiting for restart
     # permission.
-    if hookenv.status_get() != 'active':
+    if hookenv.status_get()[0] != 'active':
         helpers.set_active()
     else:
         hookenv.log('Unit status already active', DEBUG)

=== modified file 'hooks/charmhelpers/contrib/benchmark/__init__.py'
--- hooks/charmhelpers/contrib/benchmark/__init__.py	2015-05-07 11:11:42 +0000
+++ hooks/charmhelpers/contrib/benchmark/__init__.py	2016-03-17 11:00:44 +0000
@@ -63,6 +63,8 @@
 
     """
 
+    BENCHMARK_CONF = '/etc/benchmark.conf'  # Replaced in testing
+
     required_keys = [
         'hostname',
         'port',
@@ -91,7 +93,7 @@
                     break
 
             if len(config):
-                with open('/etc/benchmark.conf', 'w') as f:
+                with open(self.BENCHMARK_CONF, 'w') as f:
                     for key, val in iter(config.items()):
                         f.write("%s=%s\n" % (key, val))
 

=== modified file 'hooks/charmhelpers/contrib/charmsupport/nrpe.py'
--- hooks/charmhelpers/contrib/charmsupport/nrpe.py	2015-04-29 13:21:29 +0000
+++ hooks/charmhelpers/contrib/charmsupport/nrpe.py	2016-03-17 11:00:44 +0000
@@ -148,6 +148,13 @@
         self.description = description
         self.check_cmd = self._locate_cmd(check_cmd)
 
+    def _get_check_filename(self):
+        return os.path.join(NRPE.nrpe_confdir, '{}.cfg'.format(self.command))
+
+    def _get_service_filename(self, hostname):
+        return os.path.join(NRPE.nagios_exportdir,
+                            'service__{}_{}.cfg'.format(hostname, self.command))
+
     def _locate_cmd(self, check_cmd):
         search_path = (
             '/usr/lib/nagios/plugins',
@@ -163,9 +170,21 @@
         log('Check command not found: {}'.format(parts[0]))
         return ''
 
+    def _remove_service_files(self):
+        if not os.path.exists(NRPE.nagios_exportdir):
+            return
+        for f in os.listdir(NRPE.nagios_exportdir):
+            if f.endswith('_{}.cfg'.format(self.command)):
+                os.remove(os.path.join(NRPE.nagios_exportdir, f))
+
+    def remove(self, hostname):
+        nrpe_check_file = self._get_check_filename()
+        if os.path.exists(nrpe_check_file):
+            os.remove(nrpe_check_file)
+        self._remove_service_files()
+
     def write(self, nagios_context, hostname, nagios_servicegroups):
-        nrpe_check_file = '/etc/nagios/nrpe.d/{}.cfg'.format(
-            self.command)
+        nrpe_check_file = self._get_check_filename()
         with open(nrpe_check_file, 'w') as nrpe_check_config:
             nrpe_check_config.write("# check {}\n".format(self.shortname))
             nrpe_check_config.write("command[{}]={}\n".format(
@@ -180,9 +199,7 @@
 
     def write_service_config(self, nagios_context, hostname,
                              nagios_servicegroups):
-        for f in os.listdir(NRPE.nagios_exportdir):
-            if re.search('.*{}.cfg'.format(self.command), f):
-                os.remove(os.path.join(NRPE.nagios_exportdir, f))
+        self._remove_service_files()
 
         templ_vars = {
             'nagios_hostname': hostname,
@@ -192,8 +209,7 @@
             'command': self.command,
         }
         nrpe_service_text = Check.service_template.format(**templ_vars)
-        nrpe_service_file = '{}/service__{}_{}.cfg'.format(
-            NRPE.nagios_exportdir, hostname, self.command)
+        nrpe_service_file = self._get_service_filename(hostname)
         with open(nrpe_service_file, 'w') as nrpe_service_config:
             nrpe_service_config.write(str(nrpe_service_text))
 
@@ -218,12 +234,32 @@
         if hostname:
             self.hostname = hostname
         else:
-            self.hostname = "{}-{}".format(self.nagios_context, self.unit_name)
+            nagios_hostname = get_nagios_hostname()
+            if nagios_hostname:
+                self.hostname = nagios_hostname
+            else:
+                self.hostname = "{}-{}".format(self.nagios_context, self.unit_name)
         self.checks = []
 
     def add_check(self, *args, **kwargs):
         self.checks.append(Check(*args, **kwargs))
 
+    def remove_check(self, *args, **kwargs):
+        if kwargs.get('shortname') is None:
+            raise ValueError('shortname of check must be specified')
+
+        # Use sensible defaults if they're not specified - these are not
+        # actually used during removal, but they're required for constructing
+        # the Check object; check_disk is chosen because it's part of the
+        # nagios-plugins-basic package.
+        if kwargs.get('check_cmd') is None:
+            kwargs['check_cmd'] = 'check_disk'
+        if kwargs.get('description') is None:
+            kwargs['description'] = ''
+
+        check = Check(*args, **kwargs)
+        check.remove(self.hostname)
+
     def write(self):
         try:
             nagios_uid = pwd.getpwnam('nagios').pw_uid
@@ -260,7 +296,7 @@
     :param str relation_name: Name of relation nrpe sub joined to
     """
     for rel in relations_of_type(relation_name):
-        if 'nagios_hostname' in rel:
+        if 'nagios_host_context' in rel:
             return rel['nagios_host_context']
 
 
@@ -301,11 +337,13 @@
         upstart_init = '/etc/init/%s.conf' % svc
         sysv_init = '/etc/init.d/%s' % svc
         if os.path.exists(upstart_init):
-            nrpe.add_check(
-                shortname=svc,
-                description='process check {%s}' % unit_name,
-                check_cmd='check_upstart_job %s' % svc
-            )
+            # Don't add a check for these services from neutron-gateway
+            if svc not in ['ext-port', 'os-charm-phy-nic-mtu']:
+                nrpe.add_check(
+                    shortname=svc,
+                    description='process check {%s}' % unit_name,
+                    check_cmd='check_upstart_job %s' % svc
+                )
         elif os.path.exists(sysv_init):
             cronpath = '/etc/cron.d/nagios-service-check-%s' % svc
             cron_file = ('*/5 * * * * root '

=== modified file 'hooks/charmhelpers/contrib/network/ufw.py'
--- hooks/charmhelpers/contrib/network/ufw.py	2015-02-18 14:24:32 +0000
+++ hooks/charmhelpers/contrib/network/ufw.py	2016-03-17 11:00:44 +0000
@@ -40,7 +40,9 @@
 import re
 import os
 import subprocess
+
 from charmhelpers.core import hookenv
+from charmhelpers.core.kernel import modprobe, is_module_loaded
 
 __author__ = "Felipe Reyes <[e-mail]>"
 
@@ -82,14 +84,11 @@
     # do we have IPv6 in the machine?
     if os.path.isdir('/proc/sys/net/ipv6'):
         # is ip6tables kernel module loaded?
-        lsmod = subprocess.check_output(['lsmod'], universal_newlines=True)
-        matches = re.findall('^ip6_tables[ ]+', lsmod, re.M)
-        if len(matches) == 0:
+        if not is_module_loaded('ip6_tables'):
             # ip6tables support isn't complete, let's try to load it
             try:
-                subprocess.check_output(['modprobe', 'ip6_tables'],
-                                        universal_newlines=True)
-                # great, we could load the module
+                modprobe('ip6_tables')
+                # great, we can load the module
                 return True
             except subprocess.CalledProcessError as ex:
                 hookenv.log("Couldn't load ip6_tables module: %s" % ex.output,
@@ -180,7 +179,43 @@
         return True
 
 
-def modify_access(src, dst='any', port=None, proto=None, action='allow'):
+def default_policy(policy='deny', direction='incoming'):
+    """
+    Changes the default policy for traffic `direction`
+
+    :param policy: allow, deny or reject
+    :param direction: traffic direction, possible values: incoming, outgoing,
+                      routed
+    """
+    if policy not in ['allow', 'deny', 'reject']:
+        raise UFWError(('Unknown policy %s, valid values: '
+                        'allow, deny, reject') % policy)
+
+    if direction not in ['incoming', 'outgoing', 'routed']:
+        raise UFWError(('Unknown direction %s, valid values: '
+                        'incoming, outgoing, routed') % direction)
+
+    output = subprocess.check_output(['ufw', 'default', policy, direction],
+                                     universal_newlines=True,
+                                     env={'LANG': 'en_US',
+                                          'PATH': os.environ['PATH']})
+    hookenv.log(output, level='DEBUG')
+
+    m = re.findall("^Default %s policy changed to '%s'\n" % (direction,
+                                                             policy),
+                   output, re.M)
+    if len(m) == 0:
+        hookenv.log("ufw couldn't change the default policy to %s for %s"
+                    % (policy, direction), level='WARN')
+        return False
+    else:
+        hookenv.log("ufw default policy for %s changed to %s"
+                    % (direction, policy), level='INFO')
+        return True
+
+
+def modify_access(src, dst='any', port=None, proto=None, action='allow',
+                  index=None):
     """
     Grant access to an address or subnet
 
@@ -192,6 +227,8 @@
     :param port: destiny port
     :param proto: protocol (tcp or udp)
     :param action: `allow` or `delete`
+    :param index: if different from None the rule is inserted at the given
+                  `index`.
     """
     if not is_enabled():
         hookenv.log('ufw is disabled, skipping modify_access()', level='WARN')
@@ -199,6 +236,8 @@
 
     if action == 'delete':
         cmd = ['ufw', 'delete', 'allow']
+    elif index is not None:
+        cmd = ['ufw', 'insert', str(index), action]
     else:
         cmd = ['ufw', action]
 
@@ -227,7 +266,7 @@
                     level='ERROR')
 
 
-def grant_access(src, dst='any', port=None, proto=None):
+def grant_access(src, dst='any', port=None, proto=None, index=None):
     """
     Grant access to an address or subnet
 
@@ -238,8 +277,11 @@
                 field has to be set.
     :param port: destiny port
     :param proto: protocol (tcp or udp)
+    :param index: if different from None the rule is inserted at the given
+                  `index`.
     """
-    return modify_access(src, dst=dst, port=port, proto=proto, action='allow')
+    return modify_access(src, dst=dst, port=port, proto=proto, action='allow',
+                         index=index)
 
 
 def revoke_access(src, dst='any', port=None, proto=None):

=== modified file 'hooks/charmhelpers/contrib/templating/jinja.py'
--- hooks/charmhelpers/contrib/templating/jinja.py	2015-01-26 13:07:31 +0000
+++ hooks/charmhelpers/contrib/templating/jinja.py	2016-03-17 11:00:44 +0000
@@ -18,14 +18,15 @@
 Templating using the python-jinja2 package.
 """
 import six
-from charmhelpers.fetch import apt_install
+from charmhelpers.fetch import apt_install, apt_update
 try:
     import jinja2
 except ImportError:
+    apt_update(fatal=True)
     if six.PY3:
-        apt_install(["python3-jinja2"])
+        apt_install(["python3-jinja2"], fatal=True)
     else:
-        apt_install(["python-jinja2"])
+        apt_install(["python-jinja2"], fatal=True)
     import jinja2
 
 

=== modified file 'hooks/charmhelpers/coordinator.py'
--- hooks/charmhelpers/coordinator.py	2015-06-19 10:21:21 +0000
+++ hooks/charmhelpers/coordinator.py	2016-03-17 11:00:44 +0000
@@ -29,10 +29,10 @@
 Services Framework Usage
 ========================
 
-Ensure a peer relation is defined in metadata.yaml. Instantiate a
+Ensure a peers relation is defined in metadata.yaml. Instantiate a
 BaseCoordinator subclass before invoking ServiceManager.manage().
 Ensure that ServiceManager.manage() is wired up to the leader-elected,
-leader-settings-changed, peer relation-changed and peer
+leader-settings-changed, peers relation-changed and peers
 relation-departed hooks in addition to any other hooks you need, or your
 service will deadlock.
 
@@ -90,7 +90,7 @@
 Traditional Usage
 =================
 
-Ensure a peer relationis defined in metadata.yaml.
+Ensure a peers relation is defined in metadata.yaml.
 
 If you are using charmhelpers.core.hookenv.Hooks, ensure that a
 BaseCoordinator subclass is instantiated before calling Hooks.execute.
@@ -151,7 +151,7 @@
         hookenv.service_restart('myservice')
 
     @hooks.hook('install', 'config-changed', 'upgrade-charm',
-                # Peer and leader hooks must be wired up.
+                # Peers and leader hooks must be wired up.
                 'cluster-relation-changed', 'cluster-relation-departed',
                 'leader-elected', 'leader-settings-changed')
     def default_hook():
@@ -174,7 +174,7 @@
 Locks are released at the end of the hook they are acquired in. This may
 be the current hook if the unit is leader and the lock is free. It is
 more likely a future hook (probably leader-settings-changed, possibly
-the peer relation-changed or departed hook, potentially any hook).
+the peers relation-changed or departed hook, potentially any hook).
 
 Whenever a charm needs to perform a coordinated action it will acquire()
 the lock and perform the action immediately if acquisition is
@@ -189,16 +189,16 @@
 If the unit is the leader, then it may be able to grant its own lock
 and perform the action immediately in the source hook. If the unit is
 the leader and cannot immediately grant the lock, then its only
-guaranteed chance of acquiring the lock is in the peer relation-joined,
-relation-changed or peer relation-departed hooks when another unit has
-released it (the only channel to communicate to the leader is the peer
+guaranteed chance of acquiring the lock is in the peers relation-joined,
+relation-changed or peers relation-departed hooks when another unit has
+released it (the only channel to communicate to the leader is the peers
 relation). If the unit is not the leader, then it is unlikely the lock
 is granted in the source hook (a previous hook must have also made the
 request for this to happen). A non-leader is notified about the lock via
 leader settings. These changes may be visible in any hook, even before
 the leader-settings-changed hook has been invoked. Or the requesting
 unit may be promoted to leader after making a request, in which case the
-lock may be granted in leader-elected or in a future peer
+lock may be granted in leader-elected or in a future peers
 relation-changed or relation-departed hook.
 
 This could be simpler if leader-settings-changed was invoked on the
@@ -255,10 +255,10 @@
     def __init__(self, relation_key='coordinator', peer_relation_name=None):
         '''Instatiate a Coordinator.
 
-        Data is stored on the peer relation and in leadership storage
+        Data is stored on the peers relation and in leadership storage
         under the provided relation_key.
 
-        The peer relation is identified by peer_relation_name, and defaults
+        The peers relation is identified by peer_relation_name, and defaults
         to the first one found in metadata.yaml.
         '''
         # Most initialization is deferred, since invoking hook tools from
@@ -310,13 +310,13 @@
 
         Do not mindlessly call this method, as it triggers a cascade of
         hooks. For example, if you call acquire() every time in your
-        peer relation-changed hook you will end up with an infinite loop
+        peers relation-changed hook you will end up with an infinite loop
         of hooks. It should almost always be guarded by some condition.
         '''
         unit = hookenv.local_unit()
         ts = self.requests[unit].get(lock)
         if not ts:
-            # If there is no outstanding request on the peer relation,
+            # If there is no outstanding request on the peers relation,
             # create one.
             self.requests.setdefault(lock, {})
             self.requests[unit][lock] = _timestamp()
@@ -329,7 +329,7 @@
 
         # If the unit making the request also happens to be the
         # leader, it must handle the request now. Even though the
-        # request has been stored on the peer relation, the peer
+        # request has been stored on the peers relation, the peers
         # relation-changed hook will not be triggered.
         if hookenv.is_leader():
             return self.grant(lock, unit)
@@ -476,13 +476,13 @@
 
         local_unit = hookenv.local_unit()
 
-        # All requests must be stored on the peer relation. This is
+        # All requests must be stored on the peers relation. This is
         # the only channel units have to communicate with the leader.
         # Even the leader needs to store its requests here, as a
         # different unit may be leader by the time the request can be
         # granted.
         if self.relid is None:
-            # The peer relation is not available. Maybe we are early in
+            # The peers relation is not available. Maybe we are early in
             # the units's lifecycle. Maybe this unit is standalone.
             # Fallback to using local state.
             self.msg('No peer relation. Loading local state')
@@ -490,7 +490,7 @@
         else:
             self.requests = self._load_peer_state()
             if local_unit not in self.requests:
-                # The peer relation has just been joined. Update any state
+                # The peers relation has just been joined. Update any state
                 # loaded from our peers with our local state.
                 self.msg('New peer relation. Merging local state')
                 self.requests[local_unit] = self._load_local_state()
@@ -513,7 +513,7 @@
         local_unit = hookenv.local_unit()
 
         if self.relid is None:
-            # No peer relation yet. Fallback to local state.
+            # No peers relation yet. Fallback to local state.
             self.msg('No peer relation. Saving local state')
             self._save_local_state(self.requests[local_unit])
         else:

=== added file 'hooks/charmhelpers/core/files.py'
--- hooks/charmhelpers/core/files.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/files.py	2016-03-17 11:00:44 +0000
@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2014-2015 Canonical Limited.
+#
+# This file is part of charm-helpers.
+#
+# charm-helpers is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# charm-helpers is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+
+__author__ = 'Jorge Niedbalski <[e-mail]>'
+
+import os
+import subprocess
+
+
+def sed(filename, before, after, flags='g'):
+    """
+    Search and replaces the given pattern on filename.
+
+    :param filename: relative or absolute file path.
+    :param before: expression to be replaced (see 'man sed')
+    :param after: expression to replace with (see 'man sed')
+    :param flags: sed-compatible regex flags in example, to make
+    the  search and replace case insensitive, specify ``flags="i"``.
+    The ``g`` flag is always specified regardless, so you do not
+    need to remember to include it when overriding this parameter.
+    :returns: If the sed command exit code was zero then return,
+    otherwise raise CalledProcessError.
+    """
+    expression = r's/{0}/{1}/{2}'.format(before,
+                                         after, flags)
+
+    return subprocess.check_call(["sed", "-i", "-r", "-e",
+                                  expression,
+                                  os.path.expanduser(filename)])

=== modified file 'hooks/charmhelpers/core/hookenv.py'
--- hooks/charmhelpers/core/hookenv.py	2015-06-12 13:53:43 +0000
+++ hooks/charmhelpers/core/hookenv.py	2016-03-17 11:00:44 +0000
@@ -21,12 +21,14 @@
 #  Charm Helpers Developers <[e-mail]>
 
 from __future__ import print_function
+import copy
 from distutils.version import LooseVersion
 from functools import wraps
 import glob
 import os
 import json
 import yaml
+import socket
 import subprocess
 import sys
 import errno
@@ -73,6 +75,7 @@
         res = func(*args, **kwargs)
         cache[key] = res
         return res
+    wrapper._wrapped = func
     return wrapper
 
 
@@ -172,9 +175,19 @@
     return os.environ.get('JUJU_RELATION', None)
 
 
-def relation_id():
-    """The relation ID for the current relation hook"""
-    return os.environ.get('JUJU_RELATION_ID', None)
+@cached
+def relation_id(relation_name=None, service_or_unit=None):
+    """The relation ID for the current or a specified relation"""
+    if not relation_name and not service_or_unit:
+        return os.environ.get('JUJU_RELATION_ID', None)
+    elif relation_name and service_or_unit:
+        service_name = service_or_unit.split('/')[0]
+        for relid in relation_ids(relation_name):
+            remote_service = remote_service_name(relid)
+            if remote_service == service_name:
+                return relid
+    else:
+        raise ValueError('Must specify neither or both of relation_name and service_or_unit')
 
 
 def local_unit():
@@ -192,9 +205,20 @@
     return local_unit().split('/')[0]
 
 
+@cached
+def remote_service_name(relid=None):
+    """The remote service name for a given relation-id (or the current relation)"""
+    if relid is None:
+        unit = remote_unit()
+    else:
+        units = related_units(relid)
+        unit = units[0] if units else None
+    return unit.split('/')[0] if unit else None
+
+
 def hook_name():
     """The name of the currently executing hook"""
-    return os.path.basename(sys.argv[0])
+    return os.environ.get('JUJU_HOOK_NAME', os.path.basename(sys.argv[0]))
 
 
 class Config(dict):
@@ -246,29 +270,6 @@
             self.load_previous()
         atexit(self._implicit_save)
 
-    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 get(self, key, default=None):
-        try:
-            return self[key]
-        except KeyError:
-            return default
-
-    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.
 
@@ -286,6 +287,9 @@
         self.path = path or self.path
         with open(self.path) as f:
             self._prev_dict = json.load(f)
+        for k, v in copy.deepcopy(self._prev_dict).items():
+            if k not in self:
+                self[k] = v
 
     def changed(self, key):
         """Return True if the current value for this key is different from
@@ -317,10 +321,6 @@
         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)
 
@@ -492,6 +492,76 @@
 
 
 @cached
+def peer_relation_id():
+    '''Get the peers relation id if a peers relation has been joined, else None.'''
+    md = metadata()
+    section = md.get('peers')
+    if section:
+        for key in section:
+            relids = relation_ids(key)
+            if relids:
+                return relids[0]
+    return None
+
+
+@cached
+def relation_to_interface(relation_name):
+    """
+    Given the name of a relation, return the interface that relation uses.
+
+    :returns: The interface name, or ``None``.
+    """
+    return relation_to_role_and_interface(relation_name)[1]
+
+
+@cached
+def relation_to_role_and_interface(relation_name):
+    """
+    Given the name of a relation, return the role and the name of the interface
+    that relation uses (where role is one of ``provides``, ``requires``, or ``peers``).
+
+    :returns: A tuple containing ``(role, interface)``, or ``(None, None)``.
+    """
+    _metadata = metadata()
+    for role in ('provides', 'requires', 'peers'):
+        interface = _metadata.get(role, {}).get(relation_name, {}).get('interface')
+        if interface:
+            return role, interface
+    return None, None
+
+
+@cached
+def role_and_interface_to_relations(role, interface_name):
+    """
+    Given a role and interface name, return a list of relation names for the
+    current charm that use that interface under that role (where role is one
+    of ``provides``, ``requires``, or ``peers``).
+
+    :returns: A list of relation names.
+    """
+    _metadata = metadata()
+    results = []
+    for relation_name, relation in _metadata.get(role, {}).items():
+        if relation['interface'] == interface_name:
+            results.append(relation_name)
+    return results
+
+
+@cached
+def interface_to_relations(interface_name):
+    """
+    Given an interface, return a list of relation names for the current
+    charm that use that interface.
+
+    :returns: A list of relation names.
+    """
+    results = []
+    for role in ('provides', 'requires', 'peers'):
+        results.extend(role_and_interface_to_relations(role, interface_name))
+    return results
+
+
+@cached
 def charm_name():
     """Get the name of the current charm as is specified on metadata.yaml"""
     return metadata().get('name')
@@ -559,12 +629,60 @@
 
 def unit_public_ip():
     """Get this unit's public IP address"""
-    return unit_get('public-address')
+    return _ensure_ip(unit_get('public-address'))
 
 
 def unit_private_ip():
     """Get this unit's private IP address"""
-    return unit_get('private-address')
+    return _ensure_ip(unit_get('private-address'))
+
+
+def _ensure_ip(addr):
+    """If addr is a hostname, resolve it to an IP address"""
+    if not addr:
+        return None
+    # We need to use socket.getaddrinfo for IPv6 support.
+    info = socket.getaddrinfo(addr, None)
+    if info is None:
+        # Should never happen
+        raise ValueError("Invalid result None from getaddinfo")
+    try:
+        return info[0][4][0]
+    except IndexError:
+        # Should never happen
+        raise ValueError("Invalid result {!r} from getaddinfo".format(info))
+
+
+@cached
+def storage_get(attribute=None, storage_id=None):
+    """Get storage attributes"""
+    _args = ['storage-get', '--format=json']
+    if storage_id:
+        _args.extend(('-s', storage_id))
+    if attribute:
+        _args.append(attribute)
+    try:
+        return json.loads(subprocess.check_output(_args).decode('UTF-8'))
+    except ValueError:
+        return None
+
+
+@cached
+def storage_list(storage_name=None):
+    """List the storage IDs for the unit"""
+    _args = ['storage-list', '--format=json']
+    if storage_name:
+        _args.append(storage_name)
+    try:
+        return json.loads(subprocess.check_output(_args).decode('UTF-8'))
+    except ValueError:
+        return None
+    except OSError as e:
+        import errno
+        if e.errno == errno.ENOENT:
+            # storage-list does not exist
+            return []
+        raise
 
 
 class UnregisteredHookError(Exception):
@@ -667,6 +785,21 @@
     subprocess.check_call(['action-fail', message])
 
 
+def action_name():
+    """Get the name of the currently executing action."""
+    return os.environ.get('JUJU_ACTION_NAME')
+
+
+def action_uuid():
+    """Get the UUID of the currently executing action."""
+    return os.environ.get('JUJU_ACTION_UUID')
+
+
+def action_tag():
+    """Get the tag for the currently executing action."""
+    return os.environ.get('JUJU_ACTION_TAG')
+
+
 def status_set(workload_state, message):
     """Set the workload state with a message
 
@@ -696,25 +829,28 @@
 
 
 def status_get():
-    """Retrieve the previously set juju workload state
-
-    If the status-set command is not found then assume this is juju < 1.23 and
-    return 'unknown'
+    """Retrieve the previously set juju workload state and message
+
+    If the status-get command is not found then assume this is juju < 1.23 and
+    return 'unknown', ""
+
     """
-    cmd = ['status-get']
+    cmd = ['status-get', "--format=json", "--include-data"]
     try:
-        raw_status = subprocess.check_output(cmd, universal_newlines=True)
-        status = raw_status.rstrip()
-        return status
+        raw_status = subprocess.check_output(cmd)
     except OSError as e:
         if e.errno == errno.ENOENT:
-            return 'unknown'
+            return ('unknown', "")
         else:
             raise
+    else:
+        status = json.loads(raw_status.decode("UTF-8"))
+        return (status["status"], status["message"])
 
 
 def translate_exc(from_exc, to_exc):
     def inner_translate_exc1(f):
+        @wraps(f)
         def inner_translate_exc2(*args, **kwargs):
             try:
                 return f(*args, **kwargs)
@@ -759,6 +895,58 @@
     subprocess.check_call(cmd)
 
 
+@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
+def payload_register(ptype, klass, pid):
+    """ is used while a hook is running to let Juju know that a
+        payload has been started."""
+    cmd = ['payload-register']
+    for x in [ptype, klass, pid]:
+        cmd.append(x)
+    subprocess.check_call(cmd)
+
+
+@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
+def payload_unregister(klass, pid):
+    """ is used while a hook is running to let Juju know
+    that a payload has been manually stopped. The <class> and <id> provided
+    must match a payload that has been previously registered with juju using
+    payload-register."""
+    cmd = ['payload-unregister']
+    for x in [klass, pid]:
+        cmd.append(x)
+    subprocess.check_call(cmd)
+
+
+@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
+def payload_status_set(klass, pid, status):
+    """is used to update the current status of a registered payload.
+    The <class> and <id> provided must match a payload that has been previously
+    registered with juju using payload-register. The <status> must be one of the
+    follow: starting, started, stopping, stopped"""
+    cmd = ['payload-status-set']
+    for x in [klass, pid, status]:
+        cmd.append(x)
+    subprocess.check_call(cmd)
+
+
+@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
+def resource_get(name):
+    """used to fetch the resource path of the given name.
+
+    <name> must match a name of defined resource in metadata.yaml
+
+    returns either a path or False if resource not available
+    """
+    if not name:
+        return False
+
+    cmd = ['resource-get', name]
+    try:
+        return subprocess.check_output(cmd).decode('UTF-8')
+    except subprocess.CalledProcessError:
+        return False
+
+
 @cached
 def juju_version():
     """Full version string (eg. '1.23.3.1-trusty-amd64')"""
@@ -785,6 +973,7 @@
 
     This is useful for modules and classes to perform initialization
     and inject behavior. In particular:
+
         - Run common code before all of your hooks, such as logging
           the hook name or interesting relation data.
         - Defer object or module initialization that requires a hook
@@ -822,3 +1011,16 @@
     for callback, args, kwargs in reversed(_atexit):
         callback(*args, **kwargs)
     del _atexit[:]
+
+
+@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
+def network_get_primary_address(binding):
+    '''
+    Retrieve the primary network address for a named binding
+
+    :param binding: string. The name of a relation of extra-binding
+    :return: string. The primary IP address for the named binding
+    :raise: NotImplementedError if run on Juju < 2.0
+    '''
+    cmd = ['network-get', '--primary-address', binding]
+    return subprocess.check_output(cmd).strip()

=== modified file 'hooks/charmhelpers/core/host.py'
--- hooks/charmhelpers/core/host.py	2015-04-29 13:21:29 +0000
+++ hooks/charmhelpers/core/host.py	2016-03-17 11:00:44 +0000
@@ -24,11 +24,14 @@
 import os
 import re
 import pwd
+import glob
 import grp
 import random
 import string
 import subprocess
 import hashlib
+import functools
+import itertools
 from contextlib import contextmanager
 from collections import OrderedDict
 
@@ -62,25 +65,86 @@
     return service_result
 
 
+def service_pause(service_name, init_dir="/etc/init", initd_dir="/etc/init.d"):
+    """Pause a system service.
+
+    Stop it, and prevent it from starting again at boot."""
+    stopped = True
+    if service_running(service_name):
+        stopped = service_stop(service_name)
+    upstart_file = os.path.join(init_dir, "{}.conf".format(service_name))
+    sysv_file = os.path.join(initd_dir, service_name)
+    if init_is_systemd():
+        service('disable', service_name)
+    elif os.path.exists(upstart_file):
+        override_path = os.path.join(
+            init_dir, '{}.override'.format(service_name))
+        with open(override_path, 'w') as fh:
+            fh.write("manual\n")
+    elif os.path.exists(sysv_file):
+        subprocess.check_call(["update-rc.d", service_name, "disable"])
+    else:
+        raise ValueError(
+            "Unable to detect {0} as SystemD, Upstart {1} or"
+            " SysV {2}".format(
+                service_name, upstart_file, sysv_file))
+    return stopped
+
+
+def service_resume(service_name, init_dir="/etc/init",
+                   initd_dir="/etc/init.d"):
+    """Resume a system service.
+
+    Reenable starting again at boot. Start the service"""
+    upstart_file = os.path.join(init_dir, "{}.conf".format(service_name))
+    sysv_file = os.path.join(initd_dir, service_name)
+    if init_is_systemd():
+        service('enable', service_name)
+    elif os.path.exists(upstart_file):
+        override_path = os.path.join(
+            init_dir, '{}.override'.format(service_name))
+        if os.path.exists(override_path):
+            os.unlink(override_path)
+    elif os.path.exists(sysv_file):
+        subprocess.check_call(["update-rc.d", service_name, "enable"])
+    else:
+        raise ValueError(
+            "Unable to detect {0} as SystemD, Upstart {1} or"
+            " SysV {2}".format(
+                service_name, upstart_file, sysv_file))
+
+    started = service_running(service_name)
+    if not started:
+        started = service_start(service_name)
+    return started
+
+
 def service(action, service_name):
     """Control a system service"""
-    cmd = ['service', service_name, action]
+    if init_is_systemd():
+        cmd = ['systemctl', action, service_name]
+    else:
+        cmd = ['service', service_name, action]
     return subprocess.call(cmd) == 0
 
 
-def service_running(service):
+def service_running(service_name):
     """Determine whether a system service is running"""
-    try:
-        output = subprocess.check_output(
-            ['service', service, 'status'],
-            stderr=subprocess.STDOUT).decode('UTF-8')
-    except subprocess.CalledProcessError:
-        return False
+    if init_is_systemd():
+        return service('is-active', service_name)
     else:
-        if ("start/running" in output or "is running" in output):
-            return True
-        else:
+        try:
+            output = subprocess.check_output(
+                ['service', service_name, 'status'],
+                stderr=subprocess.STDOUT).decode('UTF-8')
+        except subprocess.CalledProcessError:
             return False
+        else:
+            if ("start/running" in output or "is running" in output or
+                    "up and running" in output):
+                return True
+            else:
+                return False
 
 
 def service_available(service_name):
@@ -95,8 +159,29 @@
         return True
 
 
-def adduser(username, password=None, shell='/bin/bash', system_user=False):
-    """Add a user to the system"""
+SYSTEMD_SYSTEM = '/run/systemd/system'
+
+
+def init_is_systemd():
+    """Return True if the host system uses systemd, False otherwise."""
+    return os.path.isdir(SYSTEMD_SYSTEM)
+
+
+def adduser(username, password=None, shell='/bin/bash', system_user=False,
+            primary_group=None, secondary_groups=None):
+    """Add a user to the system.
+
+    Will log but otherwise succeed if the user already exists.
+
+    :param str username: Username to create
+    :param str password: Password for user; if ``None``, create a system user
+    :param str shell: The default shell for the user
+    :param bool system_user: Whether to create a login or system user
+    :param str primary_group: Primary group for user; defaults to username
+    :param list secondary_groups: Optional list of additional groups
+
+    :returns: The password database entry struct, as returned by `pwd.getpwnam`
+    """
     try:
         user_info = pwd.getpwnam(username)
         log('user {0} already exists!'.format(username))
@@ -111,12 +196,32 @@
                 '--shell', shell,
                 '--password', password,
             ])
+        if not primary_group:
+            try:
+                grp.getgrnam(username)
+                primary_group = username  # avoid "group exists" error
+            except KeyError:
+                pass
+        if primary_group:
+            cmd.extend(['-g', primary_group])
+        if secondary_groups:
+            cmd.extend(['-G', ','.join(secondary_groups)])
         cmd.append(username)
         subprocess.check_call(cmd)
         user_info = pwd.getpwnam(username)
     return user_info
 
 
+def user_exists(username):
+    """Check if a user exists"""
+    try:
+        pwd.getpwnam(username)
+        user_exists = True
+    except KeyError:
+        user_exists = False
+    return user_exists
+
+
 def add_group(group_name, system_group=False):
     """Add a group to the system"""
     try:
@@ -139,11 +244,7 @@
 
 def add_user_to_group(username, group):
     """Add a user to a group"""
-    cmd = [
-        'gpasswd', '-a',
-        username,
-        group
-    ]
+    cmd = ['gpasswd', '-a', username, group]
     log("Adding user {} to group {}".format(username, group))
     subprocess.check_call(cmd)
 
@@ -202,14 +303,12 @@
 
 
 def fstab_remove(mp):
-    """Remove the given mountpoint entry from /etc/fstab
-    """
+    """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
-    """
+    """Adds the given device entry to the /etc/fstab file"""
     return Fstab.add(dev, mp, fs, options=options)
 
 
@@ -253,9 +352,19 @@
     return system_mounts
 
 
+def fstab_mount(mountpoint):
+    """Mount filesystem using fstab"""
+    cmd_args = ['mount', mountpoint]
+    try:
+        subprocess.check_output(cmd_args)
+    except subprocess.CalledProcessError as e:
+        log('Error unmounting {}\n{}'.format(mountpoint, e.output))
+        return False
+    return True
+
+
 def file_hash(path, hash_type='md5'):
-    """
-    Generate a hash checksum of the contents of 'path' or None if not found.
+    """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.
@@ -269,9 +378,22 @@
         return None
 
 
+def path_hash(path):
+    """Generate a hash checksum of all files matching 'path'. Standard
+    wildcards like '*' and '?' are supported, see documentation for the 'glob'
+    module for more information.
+
+    :return: dict: A { filename: hash } dictionary for all matched files.
+                   Empty if none found.
+    """
+    return {
+        filename: file_hash(filename)
+        for filename in glob.iglob(path)
+    }
+
+
 def check_hash(path, checksum, hash_type='md5'):
-    """
-    Validate a file using a cryptographic checksum.
+    """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`.
@@ -286,6 +408,7 @@
 
 
 class ChecksumError(ValueError):
+    """A class derived from Value error to indicate the checksum failed."""
     pass
 
 
@@ -296,36 +419,58 @@
 
         @restart_on_change({
             '/etc/ceph/ceph.conf': [ 'cinder-api', 'cinder-volume' ]
+            '/etc/apache/sites-enabled/*': [ 'apache2' ]
             })
-        def ceph_client_changed():
+        def config_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
-    ceph_client_changed function.
+    ceph_client_changed function. The apache2 service would be
+    restarted if any file matching the pattern got changed, created
+    or removed. Standard wildcards are supported, see documentation
+    for the 'glob' module for more information.
+
+    @param restart_map: {path_file_name: [service_name, ...]
+    @param stopstart: DEFAULT false; whether to stop, start OR restart
+    @returns result from decorated function
     """
     def wrap(f):
+        @functools.wraps(f)
         def wrapped_f(*args, **kwargs):
-            checksums = {}
-            for path in restart_map:
-                checksums[path] = file_hash(path)
-            f(*args, **kwargs)
-            restarts = []
-            for path in restart_map:
-                if checksums[path] != file_hash(path):
-                    restarts += restart_map[path]
-            services_list = list(OrderedDict.fromkeys(restarts))
-            if not stopstart:
-                for service_name in services_list:
-                    service('restart', service_name)
-            else:
-                for action in ['stop', 'start']:
-                    for service_name in services_list:
-                        service(action, service_name)
+            return restart_on_change_helper(
+                (lambda: f(*args, **kwargs)), restart_map, stopstart)
         return wrapped_f
     return wrap
 
 
+def restart_on_change_helper(lambda_f, restart_map, stopstart=False):
+    """Helper function to perform the restart_on_change function.
+
+    This is provided for decorators to restart services if files described
+    in the restart_map have changed after an invocation of lambda_f().
+
+    @param lambda_f: function to call.
+    @param restart_map: {file: [service, ...]}
+    @param stopstart: whether to stop, start or restart a service
+    @returns result of lambda_f()
+    """
+    checksums = {path: path_hash(path) for path in restart_map}
+    r = lambda_f()
+    # create a list of lists of the services to restart
+    restarts = [restart_map[path]
+                for path in restart_map
+                if path_hash(path) != checksums[path]]
+    # create a flat list of ordered services without duplicates from lists
+    services_list = list(OrderedDict.fromkeys(itertools.chain(*restarts)))
+    if services_list:
+        actions = ('stop', 'start') if stopstart else ('restart',)
+        for action in actions:
+            for service_name in services_list:
+                service(action, service_name)
+    return r
+
+
 def lsb_release():
     """Return /etc/lsb-release in a dict"""
     d = {}
@@ -352,36 +497,92 @@
     return(''.join(random_chars))
 
 
-def list_nics(nic_type):
-    '''Return a list of nics of given type(s)'''
+def is_phy_iface(interface):
+    """Returns True if interface is not virtual, otherwise False."""
+    if interface:
+        sys_net = '/sys/class/net'
+        if os.path.isdir(sys_net):
+            for iface in glob.glob(os.path.join(sys_net, '*')):
+                if '/virtual/' in os.path.realpath(iface):
+                    continue
+
+                if interface == os.path.basename(iface):
+                    return True
+
+    return False
+
+
+def get_bond_master(interface):
+    """Returns bond master if interface is bond slave otherwise None.
+
+    NOTE: the provided interface is expected to be physical
+    """
+    if interface:
+        iface_path = '/sys/class/net/%s' % (interface)
+        if os.path.exists(iface_path):
+            if '/virtual/' in os.path.realpath(iface_path):
+                return None
+
+            master = os.path.join(iface_path, 'master')
+            if os.path.exists(master):
+                master = os.path.realpath(master)
+                # make sure it is a bond master
+                if os.path.exists(os.path.join(master, 'bonding')):
+                    return os.path.basename(master)
+
+    return None
+
+
+def list_nics(nic_type=None):
+    """Return a list of nics of given type(s)"""
     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 + '*']
+    if nic_type:
+        for int_type in int_types:
+            cmd = ['ip', 'addr', 'show', 'label', int_type + '*']
+            ip_output = subprocess.check_output(cmd).decode('UTF-8')
+            ip_output = ip_output.split('\n')
+            ip_output = (line for line in ip_output if line)
+            for line in ip_output:
+                if line.split()[1].startswith(int_type):
+                    matched = re.search('.*: (' + int_type +
+                                        r'[0-9]+\.[0-9]+)@.*', line)
+                    if matched:
+                        iface = matched.groups()[0]
+                    else:
+                        iface = line.split()[1].replace(":", "")
+
+                    if iface not in interfaces:
+                        interfaces.append(iface)
+    else:
+        cmd = ['ip', 'a']
         ip_output = subprocess.check_output(cmd).decode('UTF-8').split('\n')
-        ip_output = (line for line in ip_output if line)
+        ip_output = (line.strip() for line in ip_output if line)
+
+        key = re.compile('^[0-9]+:\s+(.+):')
         for line in ip_output:
-            if line.split()[1].startswith(int_type):
-                matched = re.search('.*: (' + int_type + r'[0-9]+\.[0-9]+)@.*', line)
-                if matched:
-                    interface = matched.groups()[0]
-                else:
-                    interface = line.split()[1].replace(":", "")
-                interfaces.append(interface)
+            matched = re.search(key, line)
+            if matched:
+                iface = matched.group(1)
+                iface = iface.partition("@")[0]
+                if iface not in interfaces:
+                    interfaces.append(iface)
 
     return interfaces
 
 
 def set_nic_mtu(nic, mtu):
-    '''Set MTU on a network interface'''
+    """Set the Maximum Transmission Unit (MTU) on a network interface."""
     cmd = ['ip', 'link', 'set', nic, 'mtu', mtu]
     subprocess.check_call(cmd)
 
 
 def get_nic_mtu(nic):
+    """Return the Maximum Transmission Unit (MTU) for a network interface."""
     cmd = ['ip', 'addr', 'show', nic]
     ip_output = subprocess.check_output(cmd).decode('UTF-8').split('\n')
     mtu = ""
@@ -393,6 +594,7 @@
 
 
 def get_nic_hwaddr(nic):
+    """Return the Media Access Control (MAC) for a network interface."""
     cmd = ['ip', '-o', '-0', 'addr', 'show', nic]
     ip_output = subprocess.check_output(cmd).decode('UTF-8')
     hwaddr = ""
@@ -403,7 +605,7 @@
 
 
 def cmp_pkgrevno(package, revno, pkgcache=None):
-    '''Compare supplied revno with the revno of the installed package
+    """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
@@ -412,7 +614,7 @@
     This function imports apt_cache function from charmhelpers.fetch if
     the pkgcache argument is None. Be sure to add charmhelpers.fetch if
     you call this function, or pass an apt_pkg.Cache() instance.
-    '''
+    """
     import apt_pkg
     if not pkgcache:
         from charmhelpers.fetch import apt_cache
@@ -422,15 +624,30 @@
 
 
 @contextmanager
-def chdir(d):
+def chdir(directory):
+    """Change the current working directory to a different directory for a code
+    block and return the previous directory after the block exits. Useful to
+    run commands from a specificed directory.
+
+    :param str directory: The directory path to change to for this context.
+    """
     cur = os.getcwd()
     try:
-        yield os.chdir(d)
+        yield os.chdir(directory)
     finally:
         os.chdir(cur)
 
 
-def chownr(path, owner, group, follow_links=True):
+def chownr(path, owner, group, follow_links=True, chowntopdir=False):
+    """Recursively change user and group ownership of files and directories
+    in given path. Doesn't chown path itself by default, only its children.
+
+    :param str path: The string path to start changing ownership.
+    :param str owner: The owner string to use when looking up the uid.
+    :param str group: The group string to use when looking up the gid.
+    :param bool follow_links: Also Chown links if True
+    :param bool chowntopdir: Also chown path itself if True
+    """
     uid = pwd.getpwnam(owner).pw_uid
     gid = grp.getgrnam(group).gr_gid
     if follow_links:
@@ -438,6 +655,10 @@
     else:
         chown = os.lchown
 
+    if chowntopdir:
+        broken_symlink = os.path.lexists(path) and not os.path.exists(path)
+        if not broken_symlink:
+            chown(path, uid, gid)
     for root, dirs, files in os.walk(path):
         for name in dirs + files:
             full = os.path.join(root, name)
@@ -447,4 +668,28 @@
 
 
 def lchownr(path, owner, group):
+    """Recursively change user and group ownership of files and directories
+    in a given path, not following symbolic links. See the documentation for
+    'os.lchown' for more information.
+
+    :param str path: The string path to start changing ownership.
+    :param str owner: The owner string to use when looking up the uid.
+    :param str group: The group string to use when looking up the gid.
+    """
     chownr(path, owner, group, follow_links=False)
+
+
+def get_total_ram():
+    """The total amount of system RAM in bytes.
+
+    This is what is reported by the OS, and may be overcommitted when
+    there are multiple containers hosted on the same machine.
+    """
+    with open('/proc/meminfo', 'r') as f:
+        for line in f.readlines():
+            if line:
+                key, value, unit = line.split()
+                if key == 'MemTotal:':
+                    assert unit == 'kB', 'Unknown unit'
+                    return int(value) * 1024  # Classic, not KiB.
+        raise NotImplementedError()

=== added file 'hooks/charmhelpers/core/hugepage.py'
--- hooks/charmhelpers/core/hugepage.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/hugepage.py	2016-03-17 11:00:44 +0000
@@ -0,0 +1,71 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2014-2015 Canonical Limited.
+#
+# This file is part of charm-helpers.
+#
+# charm-helpers is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# charm-helpers is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+
+import yaml
+from charmhelpers.core import fstab
+from charmhelpers.core import sysctl
+from charmhelpers.core.host import (
+    add_group,
+    add_user_to_group,
+    fstab_mount,
+    mkdir,
+)
+from charmhelpers.core.strutils import bytes_from_string
+from subprocess import check_output
+
+
+def hugepage_support(user, group='hugetlb', nr_hugepages=256,
+                     max_map_count=65536, mnt_point='/run/hugepages/kvm',
+                     pagesize='2MB', mount=True, set_shmmax=False):
+    """Enable hugepages on system.
+
+    Args:
+    user (str)  -- Username to allow access to hugepages to
+    group (str) -- Group name to own hugepages
+    nr_hugepages (int) -- Number of pages to reserve
+    max_map_count (int) -- Number of Virtual Memory Areas a process can own
+    mnt_point (str) -- Directory to mount hugepages on
+    pagesize (str) -- Size of hugepages
+    mount (bool) -- Whether to Mount hugepages
+    """
+    group_info = add_group(group)
+    gid = group_info.gr_gid
+    add_user_to_group(user, group)
+    if max_map_count < 2 * nr_hugepages:
+        max_map_count = 2 * nr_hugepages
+    sysctl_settings = {
+        'vm.nr_hugepages': nr_hugepages,
+        'vm.max_map_count': max_map_count,
+        'vm.hugetlb_shm_group': gid,
+    }
+    if set_shmmax:
+        shmmax_current = int(check_output(['sysctl', '-n', 'kernel.shmmax']))
+        shmmax_minsize = bytes_from_string(pagesize) * nr_hugepages
+        if shmmax_minsize > shmmax_current:
+            sysctl_settings['kernel.shmmax'] = shmmax_minsize
+    sysctl.create(yaml.dump(sysctl_settings), '/etc/sysctl.d/10-hugepage.conf')
+    mkdir(mnt_point, owner='root', group='root', perms=0o755, force=False)
+    lfstab = fstab.Fstab()
+    fstab_entry = lfstab.get_entry_by_attr('mountpoint', mnt_point)
+    if fstab_entry:
+        lfstab.remove_entry(fstab_entry)
+    entry = lfstab.Entry('nodev', mnt_point, 'hugetlbfs',
+                         'mode=1770,gid={},pagesize={}'.format(gid, pagesize), 0, 0)
+    lfstab.add_entry(entry)
+    if mount:
+        fstab_mount(mnt_point)

=== added file 'hooks/charmhelpers/core/kernel.py'
--- hooks/charmhelpers/core/kernel.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/kernel.py	2016-03-17 11:00:44 +0000
@@ -0,0 +1,68 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2014-2015 Canonical Limited.
+#
+# This file is part of charm-helpers.
+#
+# charm-helpers is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# charm-helpers is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+
+__author__ = "Jorge Niedbalski <[e-mail]>"
+
+from charmhelpers.core.hookenv import (
+    log,
+    INFO
+)
+
+from subprocess import check_call, check_output
+import re
+
+
+def modprobe(module, persist=True):
+    """Load a kernel module and configure for auto-load on reboot."""
+    cmd = ['modprobe', module]
+
+    log('Loading kernel module %s' % module, level=INFO)
+
+    check_call(cmd)
+    if persist:
+        with open('/etc/modules', 'r+') as modules:
+            if module not in modules.read():
+                modules.write(module)
+
+
+def rmmod(module, force=False):
+    """Remove a module from the linux kernel"""
+    cmd = ['rmmod']
+    if force:
+        cmd.append('-f')
+    cmd.append(module)
+    log('Removing kernel module %s' % module, level=INFO)
+    return check_call(cmd)
+
+
+def lsmod():
+    """Shows what kernel modules are currently loaded"""
+    return check_output(['lsmod'],
+                        universal_newlines=True)
+
+
+def is_module_loaded(module):
+    """Checks if a kernel module is already loaded"""
+    matches = re.findall('^%s[ ]+' % module, lsmod(), re.M)
+    return len(matches) > 0
+
+
+def update_initramfs(version='all'):
+    """Updates an initramfs image"""
+    return check_call(["update-initramfs", "-k", version, "-u"])

=== modified file 'hooks/charmhelpers/core/services/helpers.py'
--- hooks/charmhelpers/core/services/helpers.py	2015-04-03 15:42:21 +0000
+++ hooks/charmhelpers/core/services/helpers.py	2016-03-17 11:00:44 +0000
@@ -16,7 +16,9 @@
 
 import os
 import yaml
+
 from charmhelpers.core import hookenv
+from charmhelpers.core import host
 from charmhelpers.core import templating
 
 from charmhelpers.core.services.base import ManagerCallback
@@ -239,28 +241,51 @@
     action.
 
     :param str source: The template source file, relative to
-    `$CHARM_DIR/templates`
+        `$CHARM_DIR/templates`
 
-    :param str target: The target to write the rendered template to
+    :param str target: The target to write the rendered template to (or None)
     :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
+    :param partial on_change_action: functools partial to be executed when
+                                     rendered file changes
+    :param jinja2 loader template_loader: A jinja2 template loader
+
+    :return str: The rendered template
     """
     def __init__(self, source, target,
-                 owner='root', group='root', perms=0o444):
+                 owner='root', group='root', perms=0o444,
+                 on_change_action=None, template_loader=None):
         self.source = source
         self.target = target
         self.owner = owner
         self.group = group
         self.perms = perms
+        self.on_change_action = on_change_action
+        self.template_loader = template_loader
 
     def __call__(self, manager, service_name, event_name):
+        pre_checksum = ''
+        if self.on_change_action and os.path.isfile(self.target):
+            pre_checksum = host.file_hash(self.target)
         service = manager.get_service(service_name)
-        context = {}
+        context = {'ctx': {}}
         for ctx in service.get('required_data', []):
             context.update(ctx)
-        templating.render(self.source, self.target, context,
-                          self.owner, self.group, self.perms)
+            context['ctx'].update(ctx)
+
+        result = templating.render(self.source, self.target, context,
+                                   self.owner, self.group, self.perms,
+                                   template_loader=self.template_loader)
+        if self.on_change_action:
+            if pre_checksum == host.file_hash(self.target):
+                hookenv.log(
+                    'No change detected: {}'.format(self.target),
+                    hookenv.DEBUG)
+            else:
+                self.on_change_action()
+
+        return result
 
 
 # Convenience aliases for templates

=== modified file 'hooks/charmhelpers/core/strutils.py'
--- hooks/charmhelpers/core/strutils.py	2015-04-29 13:21:29 +0000
+++ hooks/charmhelpers/core/strutils.py	2016-03-17 11:00:44 +0000
@@ -18,6 +18,7 @@
 # along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
 
 import six
+import re
 
 
 def bool_from_string(value):
@@ -40,3 +41,32 @@
 
     msg = "Unable to interpret string value '%s' as boolean" % (value)
     raise ValueError(msg)
+
+
+def bytes_from_string(value):
+    """Interpret human readable string value as bytes.
+
+    Returns int
+    """
+    BYTE_POWER = {
+        'K': 1,
+        'KB': 1,
+        'M': 2,
+        'MB': 2,
+        'G': 3,
+        'GB': 3,
+        'T': 4,
+        'TB': 4,
+        'P': 5,
+        'PB': 5,
+    }
+    if isinstance(value, six.string_types):
+        value = six.text_type(value)
+    else:
+        msg = "Unable to interpret non-string value '%s' as boolean" % (value)
+        raise ValueError(msg)
+    matches = re.match("([0-9]+)([a-zA-Z]+)", value)
+    if not matches:
+        msg = "Unable to interpret string value '%s' as bytes" % (value)
+        raise ValueError(msg)
+    return int(matches.group(1)) * (1024 ** BYTE_POWER[matches.group(2)])

=== modified file 'hooks/charmhelpers/core/templating.py'
--- hooks/charmhelpers/core/templating.py	2015-02-18 14:24:32 +0000
+++ hooks/charmhelpers/core/templating.py	2016-03-17 11:00:44 +0000
@@ -21,13 +21,14 @@
 
 
 def render(source, target, context, owner='root', group='root',
-           perms=0o444, templates_dir=None, encoding='UTF-8'):
+           perms=0o444, templates_dir=None, encoding='UTF-8', template_loader=None):
     """
     Render a template.
 
     The `source` path, if not absolute, is relative to the `templates_dir`.
 
-    The `target` path should be absolute.
+    The `target` path should be absolute.  It can also be `None`, in which
+    case no file will be written.
 
     The context should be a dict containing the values to be replaced in the
     template.
@@ -36,6 +37,9 @@
 
     If omitted, `templates_dir` defaults to the `templates` folder in the charm.
 
+    The rendered template will be written to the file as well as being returned
+    as a string.
+
     Note: Using this requires python-jinja2; if it is not installed, calling
     this will attempt to use charmhelpers.fetch.apt_install to install it.
     """
@@ -52,17 +56,26 @@
         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))
+    if template_loader:
+        template_env = Environment(loader=template_loader)
+    else:
+        if templates_dir is None:
+            templates_dir = os.path.join(hookenv.charm_dir(), 'templates')
+        template_env = Environment(loader=FileSystemLoader(templates_dir))
     try:
         source = source
-        template = loader.get_template(source)
+        template = template_env.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), owner, group, perms=0o755)
-    host.write_file(target, content.encode(encoding), owner, group, perms)
+    if target is not None:
+        target_dir = os.path.dirname(target)
+        if not os.path.exists(target_dir):
+            # This is a terrible default directory permission, as the file
+            # or its siblings will often contain secrets.
+            host.mkdir(os.path.dirname(target), owner, group, perms=0o755)
+        host.write_file(target, content.encode(encoding), owner, group, perms)
+    return content

=== modified file 'hooks/charmhelpers/core/unitdata.py'
--- hooks/charmhelpers/core/unitdata.py	2015-04-03 15:42:21 +0000
+++ hooks/charmhelpers/core/unitdata.py	2016-03-17 11:00:44 +0000
@@ -152,6 +152,7 @@
 import collections
 import contextlib
 import datetime
+import itertools
 import json
 import os
 import pprint
@@ -164,8 +165,7 @@
 class Storage(object):
     """Simple key value database for local unit state within charms.
 
-    Modifications are automatically committed at hook exit. That's
-    currently regardless of exit code.
+    Modifications are not persisted unless :meth:`flush` is called.
 
     To support dicts, lists, integer, floats, and booleans values
     are automatically json encoded/decoded.
@@ -173,8 +173,11 @@
     def __init__(self, path=None):
         self.db_path = path
         if path is None:
-            self.db_path = os.path.join(
-                os.environ.get('CHARM_DIR', ''), '.unit-state.db')
+            if 'UNIT_STATE_DB' in os.environ:
+                self.db_path = os.environ['UNIT_STATE_DB']
+            else:
+                self.db_path = os.path.join(
+                    os.environ.get('CHARM_DIR', ''), '.unit-state.db')
         self.conn = sqlite3.connect('%s' % self.db_path)
         self.cursor = self.conn.cursor()
         self.revision = None
@@ -189,15 +192,8 @@
         self.conn.close()
         self._closed = True
 
-    def _scoped_query(self, stmt, params=None):
-        if params is None:
-            params = []
-        return stmt, params
-
     def get(self, key, default=None, record=False):
-        self.cursor.execute(
-            *self._scoped_query(
-                'select data from kv where key=?', [key]))
+        self.cursor.execute('select data from kv where key=?', [key])
         result = self.cursor.fetchone()
         if not result:
             return default
@@ -206,33 +202,81 @@
         return json.loads(result[0])
 
     def getrange(self, key_prefix, strip=False):
-        stmt = "select key, data from kv where key like '%s%%'" % key_prefix
-        self.cursor.execute(*self._scoped_query(stmt))
+        """
+        Get a range of keys starting with a common prefix as a mapping of
+        keys to values.
+
+        :param str key_prefix: Common prefix among all keys
+        :param bool strip: Optionally strip the common prefix from the key
+            names in the returned dict
+        :return dict: A (possibly empty) dict of key-value mappings
+        """
+        self.cursor.execute("select key, data from kv where key like ?",
+                            ['%s%%' % key_prefix])
         result = self.cursor.fetchall()
 
         if not result:
-            return None
+            return {}
         if not strip:
             key_prefix = ''
         return dict([
             (k[len(key_prefix):], json.loads(v)) for k, v in result])
 
     def update(self, mapping, prefix=""):
+        """
+        Set the values of multiple keys at once.
+
+        :param dict mapping: Mapping of keys to values
+        :param str prefix: Optional prefix to apply to all keys in `mapping`
+            before setting
+        """
         for k, v in mapping.items():
             self.set("%s%s" % (prefix, k), v)
 
     def unset(self, key):
+        """
+        Remove a key from the database entirely.
+        """
         self.cursor.execute('delete from kv where key=?', [key])
         if self.revision and self.cursor.rowcount:
             self.cursor.execute(
                 'insert into kv_revisions values (?, ?, ?)',
                 [key, self.revision, json.dumps('DELETED')])
 
+    def unsetrange(self, keys=None, prefix=""):
+        """
+        Remove a range of keys starting with a common prefix, from the database
+        entirely.
+
+        :param list keys: List of keys to remove.
+        :param str prefix: Optional prefix to apply to all keys in ``keys``
+            before removing.
+        """
+        if keys is not None:
+            keys = ['%s%s' % (prefix, key) for key in keys]
+            self.cursor.execute('delete from kv where key in (%s)' % ','.join(['?'] * len(keys)), keys)
+            if self.revision and self.cursor.rowcount:
+                self.cursor.execute(
+                    'insert into kv_revisions values %s' % ','.join(['(?, ?, ?)'] * len(keys)),
+                    list(itertools.chain.from_iterable((key, self.revision, json.dumps('DELETED')) for key in keys)))
+        else:
+            self.cursor.execute('delete from kv where key like ?',
+                                ['%s%%' % prefix])
+            if self.revision and self.cursor.rowcount:
+                self.cursor.execute(
+                    'insert into kv_revisions values (?, ?, ?)',
+                    ['%s%%' % prefix, self.revision, json.dumps('DELETED')])
+
     def set(self, key, value):
+        """
+        Set a value in the database.
+
+        :param str key: Key to set the value for
+        :param value: Any JSON-serializable value to be set
+        """
         serialized = json.dumps(value)
 
-        self.cursor.execute(
-            'select data from kv where key=?', [key])
+        self.cursor.execute('select data from kv where key=?', [key])
         exists = self.cursor.fetchone()
 
         # Skip mutations to the same value

=== modified file 'hooks/charmhelpers/fetch/__init__.py'
--- hooks/charmhelpers/fetch/__init__.py	2015-01-26 13:07:31 +0000
+++ hooks/charmhelpers/fetch/__init__.py	2016-03-17 11:00:44 +0000
@@ -90,6 +90,22 @@
     'kilo/proposed': 'trusty-proposed/kilo',
     'trusty-kilo/proposed': 'trusty-proposed/kilo',
     'trusty-proposed/kilo': 'trusty-proposed/kilo',
+    # Liberty
+    'liberty': 'trusty-updates/liberty',
+    'trusty-liberty': 'trusty-updates/liberty',
+    'trusty-liberty/updates': 'trusty-updates/liberty',
+    'trusty-updates/liberty': 'trusty-updates/liberty',
+    'liberty/proposed': 'trusty-proposed/liberty',
+    'trusty-liberty/proposed': 'trusty-proposed/liberty',
+    'trusty-proposed/liberty': 'trusty-proposed/liberty',
+    # Mitaka
+    'mitaka': 'trusty-updates/mitaka',
+    'trusty-mitaka': 'trusty-updates/mitaka',
+    'trusty-mitaka/updates': 'trusty-updates/mitaka',
+    'trusty-updates/mitaka': 'trusty-updates/mitaka',
+    'mitaka/proposed': 'trusty-proposed/mitaka',
+    'trusty-mitaka/proposed': 'trusty-proposed/mitaka',
+    'trusty-proposed/mitaka': 'trusty-proposed/mitaka',
 }
 
 # The order of this list is very important. Handlers should be listed in from
@@ -215,19 +231,27 @@
     _run_apt_command(cmd, fatal)
 
 
+def apt_mark(packages, mark, fatal=False):
+    """Flag one or more packages using apt-mark"""
+    log("Marking {} as {}".format(packages, mark))
+    cmd = ['apt-mark', mark]
+    if isinstance(packages, six.string_types):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+
+    if fatal:
+        subprocess.check_call(cmd, universal_newlines=True)
+    else:
+        subprocess.call(cmd, universal_newlines=True)
+
+
 def apt_hold(packages, fatal=False):
-    """Hold one or more packages"""
-    cmd = ['apt-mark', 'hold']
-    if isinstance(packages, six.string_types):
-        cmd.append(packages)
-    else:
-        cmd.extend(packages)
-    log("Holding {}".format(packages))
-
-    if fatal:
-        subprocess.check_call(cmd)
-    else:
-        subprocess.call(cmd)
+    return apt_mark(packages, 'hold', fatal=fatal)
+
+
+def apt_unhold(packages, fatal=False):
+    return apt_mark(packages, 'unhold', fatal=fatal)
 
 
 def add_source(source, key=None):
@@ -370,8 +394,9 @@
     for handler in handlers:
         try:
             installed_to = handler.install(source, *args, **kwargs)
-        except UnhandledSource:
-            pass
+        except UnhandledSource as e:
+            log('Install source attempt unsuccessful: {}'.format(e),
+                level='WARNING')
     if not installed_to:
         raise UnhandledSource("No handler found for source {}".format(source))
     return installed_to
@@ -394,7 +419,7 @@
                 importlib.import_module(package),
                 classname)
             plugin_list.append(handler_class())
-        except (ImportError, AttributeError):
+        except NotImplementedError:
             # Skip missing plugins so that they can be ommitted from
             # installation if desired
             log("FetchHandler {} not found, skipping plugin".format(

=== modified file 'hooks/charmhelpers/fetch/archiveurl.py'
--- hooks/charmhelpers/fetch/archiveurl.py	2015-02-18 14:24:32 +0000
+++ hooks/charmhelpers/fetch/archiveurl.py	2016-03-17 11:00:44 +0000
@@ -77,6 +77,8 @@
     def can_handle(self, source):
         url_parts = self.parse_url(source)
         if url_parts.scheme not in ('http', 'https', 'ftp', 'file'):
+            # XXX: Why is this returning a boolean and a string? It's
+            # doomed to fail since "bool(can_handle('foo://'))"  will be True.
             return "Wrong source type"
         if get_archive_handler(self.base_url(source)):
             return True
@@ -106,7 +108,7 @@
                 install_opener(opener)
         response = urlopen(source)
         try:
-            with open(dest, 'w') as dest_file:
+            with open(dest, 'wb') as dest_file:
                 dest_file.write(response.read())
         except Exception as e:
             if os.path.isfile(dest):
@@ -155,7 +157,11 @@
             else:
                 algorithms = hashlib.algorithms_available
             if key in algorithms:
-                check_hash(dld_file, value, key)
+                if len(value) != 1:
+                    raise TypeError(
+                        "Expected 1 hash value, not %d" % len(value))
+                expected = value[0]
+                check_hash(dld_file, expected, 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	2015-01-26 13:07:31 +0000
+++ hooks/charmhelpers/fetch/bzrurl.py	2016-03-17 11:00:44 +0000
@@ -15,60 +15,50 @@
 # along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
+from subprocess import check_call
 from charmhelpers.fetch import (
     BaseFetchHandler,
-    UnhandledSource
+    UnhandledSource,
+    filter_installed_packages,
+    apt_install,
 )
 from charmhelpers.core.host import mkdir
 
-import six
-if six.PY3:
-    raise ImportError('bzrlib does not support Python3')
 
-try:
-    from bzrlib.branch import Branch
-    from bzrlib import bzrdir, workingtree, errors
-except ImportError:
-    from charmhelpers.fetch import apt_install
-    apt_install("python-bzrlib")
-    from bzrlib.branch import Branch
-    from bzrlib import bzrdir, workingtree, errors
+if filter_installed_packages(['bzr']) != []:
+    apt_install(['bzr'])
+    if filter_installed_packages(['bzr']) != []:
+        raise NotImplementedError('Unable to install bzr')
 
 
 class BzrUrlFetchHandler(BaseFetchHandler):
     """Handler for bazaar branches via generic and lp URLs"""
     def can_handle(self, source):
         url_parts = self.parse_url(source)
-        if url_parts.scheme not in ('bzr+ssh', 'lp'):
+        if url_parts.scheme not in ('bzr+ssh', 'lp', ''):
             return False
+        elif not url_parts.scheme:
+            return os.path.exists(os.path.join(source, '.bzr'))
         else:
             return True
 
     def branch(self, source, dest):
-        url_parts = self.parse_url(source)
-        # If we use lp:branchname scheme we need to load plugins
         if not self.can_handle(source):
             raise UnhandledSource("Cannot handle {}".format(source))
-        if url_parts.scheme == "lp":
-            from bzrlib.plugin import load_plugins
-            load_plugins()
-        try:
-            local_branch = bzrdir.BzrDir.create_branch_convenience(dest)
-        except errors.AlreadyControlDirError:
-            local_branch = Branch.open(dest)
-        try:
-            remote_branch = Branch.open(source)
-            remote_branch.push(local_branch)
-            tree = workingtree.WorkingTree.open(dest)
-            tree.update()
-        except Exception as e:
-            raise e
+        if os.path.exists(dest):
+            check_call(['bzr', 'pull', '--overwrite', '-d', dest, source])
+        else:
+            check_call(['bzr', 'branch', source, dest])
 
-    def install(self, source):
+    def install(self, source, dest=None):
         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 dest:
+            dest_dir = os.path.join(dest, branch_name)
+        else:
+            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:

=== modified file 'hooks/charmhelpers/fetch/giturl.py'
--- hooks/charmhelpers/fetch/giturl.py	2015-06-08 08:24:59 +0000
+++ hooks/charmhelpers/fetch/giturl.py	2016-03-17 11:00:44 +0000
@@ -15,24 +15,18 @@
 # along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
+from subprocess import check_call, CalledProcessError
 from charmhelpers.fetch import (
     BaseFetchHandler,
-    UnhandledSource
+    UnhandledSource,
+    filter_installed_packages,
+    apt_install,
 )
-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
-
-from git.exc import GitCommandError  # noqa E402
+
+if filter_installed_packages(['git']) != []:
+    apt_install(['git'])
+    if filter_installed_packages(['git']) != []:
+        raise NotImplementedError('Unable to install git')
 
 
 class GitUrlFetchHandler(BaseFetchHandler):
@@ -40,19 +34,24 @@
     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'):
+        if url_parts.scheme not in ('http', 'https', 'git', ''):
             return False
+        elif not url_parts.scheme:
+            return os.path.exists(os.path.join(source, '.git'))
         else:
             return True
 
-    def clone(self, source, dest, branch, depth=None):
+    def clone(self, source, dest, branch="master", depth=None):
         if not self.can_handle(source):
             raise UnhandledSource("Cannot handle {}".format(source))
 
-        if depth:
-            Repo.clone_from(source, dest, branch=branch, depth=depth)
+        if os.path.exists(dest):
+            cmd = ['git', '-C', dest, 'pull', source, branch]
         else:
-            Repo.clone_from(source, dest, branch=branch)
+            cmd = ['git', 'clone', source, dest, '--branch', branch]
+            if depth:
+                cmd.extend(['--depth', depth])
+        check_call(cmd)
 
     def install(self, source, branch="master", dest=None, depth=None):
         url_parts = self.parse_url(source)
@@ -62,12 +61,10 @@
         else:
             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, depth)
-        except GitCommandError as e:
-            raise UnhandledSource(e.message)
+        except CalledProcessError as e:
+            raise UnhandledSource(e)
         except OSError as e:
             raise UnhandledSource(e.strerror)
         return dest_dir

=== modified file 'hooks/helpers.py'
--- hooks/helpers.py	2016-02-26 16:47:03 +0000
+++ hooks/helpers.py	2016-03-17 11:00:44 +0000
@@ -824,7 +824,7 @@
 @logged
 def set_auth_keyspace_replication(session, settings):
     # Live operation, so keep status the same.
-    status_set(hookenv.status_get(),
+    status_set(hookenv.status_get()[0],
                'Updating system_auth rf to {!r}'.format(settings))
     statement = 'ALTER KEYSPACE system_auth WITH REPLICATION = %s'
     query(session, statement, ConsistencyLevel.ALL, (settings,))
@@ -835,7 +835,7 @@
     # Repair takes a long time, and may need to be retried due to 'snapshot
     # creation' errors, but should certainly complete within an hour since
     # the keyspace is tiny.
-    status_set(hookenv.status_get(),
+    status_set(hookenv.status_get()[0],
                'Repairing system_auth keyspace')
     nodetool('repair', 'system_auth', timeout=3600)
 

=== modified file 'tests/test_actions.py'
--- tests/test_actions.py	2016-02-26 16:47:03 +0000
+++ tests/test_actions.py	2016-03-17 11:00:44 +0000
@@ -1095,7 +1095,7 @@
     @patch('charmhelpers.core.hookenv.is_leader')
     def test_set_active(self, is_leader, status_get, status_set, seed_ips):
         is_leader.return_value = False
-        status_get.return_value = 'waiting'
+        status_get.return_value = ('waiting', '')
         seed_ips.return_value = set()
         actions.set_active('')
         status_set.assert_called_once_with('active', 'Live node')
@@ -1107,7 +1107,7 @@
     def test_set_active_seed(self, is_leader,
                              status_get, status_set, seed_ips):
         is_leader.return_value = False
-        status_get.return_value = 'waiting'
+        status_get.return_value = ('waiting', '')
         seed_ips.return_value = set([hookenv.unit_private_ip()])
         actions.set_active('')
         status_set.assert_called_once_with('active', 'Live seed')
@@ -1121,6 +1121,7 @@
     def test_set_active_service(self, is_leader,
                                 status_get, status_set, service_status_set,
                                 seed_ips, num_nodes):
+        status_get.return_value = ('waiting', '')
         is_leader.return_value = True
         seed_ips.return_value = set([hookenv.unit_private_ip()])
         num_nodes.return_value = 1

=== modified file 'tests/test_helpers.py'
--- tests/test_helpers.py	2016-02-26 16:47:03 +0000
+++ tests/test_helpers.py	2016-03-17 11:00:44 +0000
@@ -1339,7 +1339,7 @@
     @patch('helpers.query')
     def test_set_auth_keyspace_replication(self, query,
                                            status_get, status_set):
-        status_get.return_value = 'active'
+        status_get.return_value = ('active', '')
         settings = dict(json=True)
         helpers.set_auth_keyspace_replication(sentinel.session, settings)
         query.assert_called_once_with(sentinel.session,
@@ -1351,7 +1351,7 @@
     @patch('charmhelpers.core.hookenv.status_get')
     @patch('helpers.nodetool')
     def test_repair_auth_keyspace(self, nodetool, status_get, status_set):
-        status_get.return_value = sentinel.status
+        status_get.return_value = (sentinel.status, '')
         helpers.repair_auth_keyspace()
         status_set.assert_called_once_with(sentinel.status,
                                            'Repairing system_auth keyspace')