Merge lp:~facundo/charms/trusty/tanuki-spec-manager/first-draft into lp:~tanuki/charms/trusty/tanuki-spec-manager/trunk

[Facundo Batista]

First draft of the charm for Spec Manager.

First draft of the charm for Spec Manager.

[Celso Providelo (cprov)]

Facundo,

The diff is truncated, but you can land as long as you stop trying to install the spec_manager module (it will fail, because it's not installed atm) and remove the service action for filling website relation forcibly (remove the wsgi-relation-joined symlink and create the correct website-relation* ones).

[]

review: Needs Fixing

[lp:~facundo/charms/trusty/tanuki-spec-manager/first-draft]

2. By Facundo Batista on 2015-06-18

Better website relation management.

[Facundo Batista (facundo)]

Done! will land

review: Approve

[lp:~facundo/charms/trusty/tanuki-spec-manager/first-draft]

3. By Facundo Batista on 2015-06-18

Proper cleaning and website relation handling.

[Celso Providelo (cprov)]

Nice, thanks.

review: Approve

=== added file 'README'
--- README	1970-01-01 00:00:00 +0000
+++ README	2015-06-18 17:19:58 +0000
@@ -0,0 +1,15 @@
+Overview
+--------
+
+This charm provides the Spec Manager from lp:tanuki-spec-manager
+
+Configuration
+-------------
+
+There are only two config options for this charm:
+ * config-file: A base64 encoded string with the config file to use for
+                adt-cloud-service.
+ * environment: a string, one of "development" or "production"
+
+NOTE: This expects the payload code in the form of spec-manager.tgz
+to exist with the snapshot of lp:tanuki-spec-manager that needs deploying
 
=== added file 'config.yaml'
--- config.yaml	1970-01-01 00:00:00 +0000
+++ config.yaml	2015-06-18 17:19:58 +0000
@@ -0,0 +1,10 @@
+options:
+  environment:
+    type: string
+    default: "production"
+    description: |
+      Environment (devel, staging, production, etc.) that we're running.
+  config-file:
+    type: string
+    description: |
+      base64 encoded string with the config file for adt-cloud-worker
 
=== added directory 'files'
=== added directory 'hooks'
=== added file 'hooks/actions.py'
--- hooks/actions.py	1970-01-01 00:00:00 +0000
+++ hooks/actions.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,94 @@
+import base64
+import os
+import subprocess
+
+from charmhelpers import fetch
+from charmhelpers.core import (
+    hookenv,
+    host,
+)
+from charmhelpers.core.services import helpers
+from charmhelpers.payload import (archive, execd)
+
+
+REQUIRED_PACKAGES = [
+    'python-virtualenv', 'python3-dev',
+]
+
+WSGI_USER = 'www-data'
+WSGI_GROUP = 'www-data'
+
+config = hookenv.config()
+
+SERVICE_DIR = '/srv/{}/spec-manager'.format(config['environment'])
+LOG_DIR = os.path.join(SERVICE_DIR, 'logs')
+
+
+def log_start(service_name):
+    hookenv.log('spec-manager starting')
+
+
+def basenode(service_name):
+    hookenv.log("Executing basenode")
+    execd.execd_preinstall()
+
+
+def install_packages(service_name):
+    hookenv.log('Installing dependencies...')
+    fetch.configure_sources(update=True)
+    fetch.apt_install(REQUIRED_PACKAGES, fatal=True)
+
+
+def get_cloud_service_from_tarball(service_name):
+    files_dir = os.path.join(hookenv.charm_dir(), 'files')
+    tarball = os.path.join(files_dir, 'spec-manager.tgz')
+    if not os.path.exists(SERVICE_DIR):
+        hookenv.log('Installing the code for the first time from tarball')
+        archive.extract_tarfile(tarball, os.path.dirname(SERVICE_DIR))
+
+
+def get_config_file(service_name):
+    config_file = config.get('config-file')
+    if config_file is not None:
+        with open(os.path.join(SERVICE_DIR, 'spec-manager.conf'), 'w') as f:
+            f.write(base64.b64decode(config_file))
+
+
+def install_python_packages(service_name):
+    env_dir = os.path.join(SERVICE_DIR, 'env')
+    if os.path.exists(env_dir):
+        hookenv.log('Service venv already exists, nothing to do ...')
+        return
+
+    hookenv.log('Installing python packages into the venv ...')
+    subprocess.check_call(['virtualenv', '-p', 'python3', env_dir])
+
+    pip_cache = os.path.join(hookenv.charm_dir(), 'files', 'pip-cache')
+    requirements = os.path.join(SERVICE_DIR, 'requirements_run.txt')
+
+    hookenv.log('Installing from download cache.')
+    subprocess.check_call(['%s/bin/pip' % env_dir,
+                           'install',
+                           '--no-index',
+                           '--find-links={}'.format(pip_cache),
+                           '-r', requirements])
+
+    subprocess.check_call(['%s/bin/pip' % env_dir,
+                           'install', '--no-deps', '-e', SERVICE_DIR])
+
+
+def prepare_for_wsgi(service_name):
+    host.adduser(WSGI_USER)
+    host.add_group(WSGI_GROUP)
+    host.add_user_to_group(WSGI_USER, WSGI_GROUP)
+    if not os.path.exists(LOG_DIR):
+        host.mkdir(LOG_DIR, WSGI_USER, WSGI_GROUP, perms=0o755)
+
+
+class WebsiteRelation(helpers.HttpRelation):
+
+    def provide_data(self):
+        hookenv.log('Providing Website relation data.')
+        data = super(WebsiteRelation, self).provide_data()
+        data['port'] = 8000
+        return data
 
=== added directory 'hooks/charmhelpers'
=== added file 'hooks/charmhelpers/__init__.py'
--- hooks/charmhelpers/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,38 @@
+# 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/>.
+
+# 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'
=== added file 'hooks/charmhelpers/contrib/__init__.py'
--- hooks/charmhelpers/contrib/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,15 @@
+# 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/>.
 
=== added directory 'hooks/charmhelpers/contrib/amulet'
=== added file 'hooks/charmhelpers/contrib/amulet/__init__.py'
--- hooks/charmhelpers/contrib/amulet/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/amulet/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,15 @@
+# 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/>.
 
=== added file 'hooks/charmhelpers/contrib/amulet/deployment.py'
--- hooks/charmhelpers/contrib/amulet/deployment.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/amulet/deployment.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,93 @@
+# 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 amulet
+import os
+import six
+
+
+class AmuletDeployment(object):
+    """Amulet deployment.
+
+       This class provides generic Amulet deployment and test runner
+       methods.
+       """
+
+    def __init__(self, series=None):
+        """Initialize the deployment environment."""
+        self.series = None
+
+        if series:
+            self.series = series
+            self.d = amulet.Deployment(series=self.series)
+        else:
+            self.d = amulet.Deployment()
+
+    def _add_services(self, this_service, other_services):
+        """Add services.
+
+           Add services to the deployment where this_service is the local charm
+           that we're testing and other_services are the other services that
+           are being used in the local amulet tests.
+           """
+        if this_service['name'] != os.path.basename(os.getcwd()):
+            s = this_service['name']
+            msg = "The charm's root directory name needs to be {}".format(s)
+            amulet.raise_status(amulet.FAIL, msg=msg)
+
+        if 'units' not in this_service:
+            this_service['units'] = 1
+
+        self.d.add(this_service['name'], units=this_service['units'])
+
+        for svc in other_services:
+            if 'location' in svc:
+                branch_location = svc['location']
+            elif self.series:
+                branch_location = 'cs:{}/{}'.format(self.series, svc['name']),
+            else:
+                branch_location = None
+
+            if 'units' not in svc:
+                svc['units'] = 1
+
+            self.d.add(svc['name'], charm=branch_location, units=svc['units'])
+
+    def _add_relations(self, relations):
+        """Add all of the relations for the services."""
+        for k, v in six.iteritems(relations):
+            self.d.relate(k, v)
+
+    def _configure_services(self, configs):
+        """Configure all of the services."""
+        for service, config in six.iteritems(configs):
+            self.d.configure(service, config)
+
+    def _deploy(self):
+        """Deploy environment and wait for all hooks to finish executing."""
+        try:
+            self.d.setup(timeout=900)
+            self.d.sentry.wait(timeout=900)
+        except amulet.helpers.TimeoutError:
+            amulet.raise_status(amulet.FAIL, msg="Deployment timed out")
+        except Exception:
+            raise
+
+    def run_tests(self):
+        """Run all of the methods that are prefixed with 'test_'."""
+        for test in dir(self):
+            if test.startswith('test_'):
+                getattr(self, test)()
 
=== added file 'hooks/charmhelpers/contrib/amulet/utils.py'
--- hooks/charmhelpers/contrib/amulet/utils.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/amulet/utils.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,194 @@
+# 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 ConfigParser
+import io
+import logging
+import re
+import sys
+import time
+
+import six
+
+
+class AmuletUtils(object):
+    """Amulet utilities.
+
+       This class provides common utility functions that are used by Amulet
+       tests.
+       """
+
+    def __init__(self, log_level=logging.ERROR):
+        self.log = self.get_logger(level=log_level)
+
+    def get_logger(self, name="amulet-logger", level=logging.DEBUG):
+        """Get a logger object that will log to stdout."""
+        log = logging
+        logger = log.getLogger(name)
+        fmt = log.Formatter("%(asctime)s %(funcName)s "
+                            "%(levelname)s: %(message)s")
+
+        handler = log.StreamHandler(stream=sys.stdout)
+        handler.setLevel(level)
+        handler.setFormatter(fmt)
+
+        logger.addHandler(handler)
+        logger.setLevel(level)
+
+        return logger
+
+    def valid_ip(self, ip):
+        if re.match(r"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$", ip):
+            return True
+        else:
+            return False
+
+    def valid_url(self, url):
+        p = re.compile(
+            r'^(?:http|ftp)s?://'
+            r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|'  # noqa
+            r'localhost|'
+            r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})'
+            r'(?::\d+)?'
+            r'(?:/?|[/?]\S+)$',
+            re.IGNORECASE)
+        if p.match(url):
+            return True
+        else:
+            return False
+
+    def validate_services(self, commands):
+        """Validate services.
+
+           Verify the specified services are running on the corresponding
+           service units.
+           """
+        for k, v in six.iteritems(commands):
+            for cmd in v:
+                output, code = k.run(cmd)
+                if code != 0:
+                    return "command `{}` returned {}".format(cmd, str(code))
+        return None
+
+    def _get_config(self, unit, filename):
+        """Get a ConfigParser object for parsing a unit's config file."""
+        file_contents = unit.file_contents(filename)
+        config = ConfigParser.ConfigParser()
+        config.readfp(io.StringIO(file_contents))
+        return config
+
+    def validate_config_data(self, sentry_unit, config_file, section,
+                             expected):
+        """Validate config file data.
+
+           Verify that the specified section of the config file contains
+           the expected option key:value pairs.
+           """
+        config = self._get_config(sentry_unit, config_file)
+
+        if section != 'DEFAULT' and not config.has_section(section):
+            return "section [{}] does not exist".format(section)
+
+        for k in expected.keys():
+            if not config.has_option(section, k):
+                return "section [{}] is missing option {}".format(section, k)
+            if config.get(section, k) != expected[k]:
+                return "section [{}] {}:{} != expected {}:{}".format(
+                       section, k, config.get(section, k), k, expected[k])
+        return None
+
+    def _validate_dict_data(self, expected, actual):
+        """Validate dictionary data.
+
+           Compare expected dictionary data vs actual dictionary data.
+           The values in the 'expected' dictionary can be strings, bools, ints,
+           longs, or can be a function that evaluate a variable and returns a
+           bool.
+           """
+        for k, v in six.iteritems(expected):
+            if k in actual:
+                if (isinstance(v, six.string_types) or
+                        isinstance(v, bool) or
+                        isinstance(v, six.integer_types)):
+                    if v != actual[k]:
+                        return "{}:{}".format(k, actual[k])
+                elif not v(actual[k]):
+                    return "{}:{}".format(k, actual[k])
+            else:
+                return "key '{}' does not exist".format(k)
+        return None
+
+    def validate_relation_data(self, sentry_unit, relation, expected):
+        """Validate actual relation data based on expected relation data."""
+        actual = sentry_unit.relation(relation[0], relation[1])
+        self.log.debug('actual: {}'.format(repr(actual)))
+        return self._validate_dict_data(expected, actual)
+
+    def _validate_list_data(self, expected, actual):
+        """Compare expected list vs actual list data."""
+        for e in expected:
+            if e not in actual:
+                return "expected item {} not found in actual list".format(e)
+        return None
+
+    def not_null(self, string):
+        if string is not None:
+            return True
+        else:
+            return False
+
+    def _get_file_mtime(self, sentry_unit, filename):
+        """Get last modification time of file."""
+        return sentry_unit.file_stat(filename)['mtime']
+
+    def _get_dir_mtime(self, sentry_unit, directory):
+        """Get last modification time of directory."""
+        return sentry_unit.directory_stat(directory)['mtime']
+
+    def _get_proc_start_time(self, sentry_unit, service, pgrep_full=False):
+        """Get process' start time.
+
+           Determine start time of the process based on the last modification
+           time of the /proc/pid directory. If pgrep_full is True, the process
+           name is matched against the full command line.
+           """
+        if pgrep_full:
+            cmd = 'pgrep -o -f {}'.format(service)
+        else:
+            cmd = 'pgrep -o {}'.format(service)
+        proc_dir = '/proc/{}'.format(sentry_unit.run(cmd)[0].strip())
+        return self._get_dir_mtime(sentry_unit, proc_dir)
+
+    def service_restarted(self, sentry_unit, service, filename,
+                          pgrep_full=False, sleep_time=20):
+        """Check if service was restarted.
+
+           Compare a service's start time vs a file's last modification time
+           (such as a config file for that service) to determine if the service
+           has been restarted.
+           """
+        time.sleep(sleep_time)
+        if (self._get_proc_start_time(sentry_unit, service, pgrep_full) >=
+                self._get_file_mtime(sentry_unit, filename)):
+            return True
+        else:
+            return False
+
+    def relation_error(self, name, data):
+        return 'unexpected relation data in {} - {}'.format(name, data)
+
+    def endpoint_error(self, name, data):
+        return 'unexpected endpoint data in {} - {}'.format(name, data)
 
=== added directory 'hooks/charmhelpers/contrib/ansible'
=== added file 'hooks/charmhelpers/contrib/ansible/__init__.py'
--- hooks/charmhelpers/contrib/ansible/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/ansible/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,190 @@
+# 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/>.
+
+# Copyright 2013 Canonical Ltd.
+#
+# Authors:
+#  Charm Helpers Developers <[e-mail]>
+"""Charm Helpers ansible - declare the state of your machines.
+
+This helper enables you to declare your machine state, rather than
+program it procedurally (and have to test each change to your procedures).
+Your install hook can be as simple as::
+
+    {{{
+    import charmhelpers.contrib.ansible
+
+
+    def install():
+        charmhelpers.contrib.ansible.install_ansible_support()
+        charmhelpers.contrib.ansible.apply_playbook('playbooks/install.yaml')
+    }}}
+
+and won't need to change (nor will its tests) when you change the machine
+state.
+
+All of your juju config and relation-data are available as template
+variables within your playbooks and templates. An install playbook looks
+something like::
+
+    {{{
+    ---
+    - hosts: localhost
+      user: root
+
+      tasks:
+        - name: Add private repositories.
+          template:
+            src: ../templates/private-repositories.list.jinja2
+            dest: /etc/apt/sources.list.d/private.list
+
+        - name: Update the cache.
+          apt: update_cache=yes
+
+        - name: Install dependencies.
+          apt: pkg={{ item }}
+          with_items:
+            - python-mimeparse
+            - python-webob
+            - sunburnt
+
+        - name: Setup groups.
+          group: name={{ item.name }} gid={{ item.gid }}
+          with_items:
+            - { name: 'deploy_user', gid: 1800 }
+            - { name: 'service_user', gid: 1500 }
+
+      ...
+    }}}
+
+Read more online about `playbooks`_ and standard ansible `modules`_.
+
+.. _playbooks: http://www.ansibleworks.com/docs/playbooks.html
+.. _modules: http://www.ansibleworks.com/docs/modules.html
+
+"""
+import os
+import subprocess
+
+import charmhelpers.contrib.templating.contexts
+import charmhelpers.core.host
+import charmhelpers.core.hookenv
+import charmhelpers.fetch
+
+
+charm_dir = os.environ.get('CHARM_DIR', '')
+ansible_hosts_path = '/etc/ansible/hosts'
+# Ansible will automatically include any vars in the following
+# file in its inventory when run locally.
+ansible_vars_path = '/etc/ansible/host_vars/localhost'
+
+
+def install_ansible_support(from_ppa=True, ppa_location='ppa:rquillo/ansible'):
+    """Installs the ansible package.
+
+    By default it is installed from the `PPA`_ linked from
+    the ansible `website`_ or from a ppa specified by a charm config..
+
+    .. _PPA: https://launchpad.net/~rquillo/+archive/ansible
+    .. _website: http://docs.ansible.com/intro_installation.html#latest-releases-via-apt-ubuntu
+
+    If from_ppa is empty, you must ensure that the package is available
+    from a configured repository.
+    """
+    if from_ppa:
+        charmhelpers.fetch.add_source(ppa_location)
+        charmhelpers.fetch.apt_update(fatal=True)
+    charmhelpers.fetch.apt_install('ansible')
+    with open(ansible_hosts_path, 'w+') as hosts_file:
+        hosts_file.write('localhost ansible_connection=local')
+
+
+def apply_playbook(playbook, tags=None):
+    tags = tags or []
+    tags = ",".join(tags)
+    charmhelpers.contrib.templating.contexts.juju_state_to_yaml(
+        ansible_vars_path, namespace_separator='__',
+        allow_hyphens_in_keys=False)
+    # we want ansible's log output to be unbuffered
+    env = os.environ.copy()
+    env['PYTHONUNBUFFERED'] = "1"
+    call = [
+        'ansible-playbook',
+        '-c',
+        'local',
+        playbook,
+    ]
+    if tags:
+        call.extend(['--tags', '{}'.format(tags)])
+    subprocess.check_call(call, env=env)
+
+
+class AnsibleHooks(charmhelpers.core.hookenv.Hooks):
+    """Run a playbook with the hook-name as the tag.
+
+    This helper builds on the standard hookenv.Hooks helper,
+    but additionally runs the playbook with the hook-name specified
+    using --tags (ie. running all the tasks tagged with the hook-name).
+
+    Example::
+
+        hooks = AnsibleHooks(playbook_path='playbooks/my_machine_state.yaml')
+
+        # All the tasks within my_machine_state.yaml tagged with 'install'
+        # will be run automatically after do_custom_work()
+        @hooks.hook()
+        def install():
+            do_custom_work()
+
+        # For most of your hooks, you won't need to do anything other
+        # than run the tagged tasks for the hook:
+        @hooks.hook('config-changed', 'start', 'stop')
+        def just_use_playbook():
+            pass
+
+        # As a convenience, you can avoid the above noop function by specifying
+        # the hooks which are handled by ansible-only and they'll be registered
+        # for you:
+        # hooks = AnsibleHooks(
+        #     'playbooks/my_machine_state.yaml',
+        #     default_hooks=['config-changed', 'start', 'stop'])
+
+        if __name__ == "__main__":
+            # execute a hook based on the name the program is called by
+            hooks.execute(sys.argv)
+
+    """
+
+    def __init__(self, playbook_path, default_hooks=None):
+        """Register any hooks handled by ansible."""
+        super(AnsibleHooks, self).__init__()
+
+        self.playbook_path = playbook_path
+
+        default_hooks = default_hooks or []
+
+        def noop(*args, **kwargs):
+            pass
+
+        for hook in default_hooks:
+            self.register(hook, noop)
+
+    def execute(self, args):
+        """Execute the hook followed by the playbook using the hook as tag."""
+        super(AnsibleHooks, self).execute(args)
+        hook_name = os.path.basename(args[0])
+        charmhelpers.contrib.ansible.apply_playbook(
+            self.playbook_path, tags=[hook_name])
 
=== added directory 'hooks/charmhelpers/contrib/charmhelpers'
=== added file 'hooks/charmhelpers/contrib/charmhelpers/__init__.py'
--- hooks/charmhelpers/contrib/charmhelpers/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/charmhelpers/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,208 @@
+# 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/>.
+
+# Copyright 2012 Canonical Ltd.  This software is licensed under the
+# GNU Affero General Public License version 3 (see the file LICENSE).
+
+import warnings
+warnings.warn("contrib.charmhelpers is deprecated", DeprecationWarning)  # noqa
+
+import operator
+import tempfile
+import time
+import yaml
+import subprocess
+
+import six
+if six.PY3:
+    from urllib.request import urlopen
+    from urllib.error import (HTTPError, URLError)
+else:
+    from urllib2 import (urlopen, HTTPError, URLError)
+
+"""Helper functions for writing Juju charms in Python."""
+
+__metaclass__ = type
+__all__ = [
+    # 'get_config',             # core.hookenv.config()
+    # 'log',                    # core.hookenv.log()
+    # 'log_entry',              # core.hookenv.log()
+    # 'log_exit',               # core.hookenv.log()
+    # 'relation_get',           # core.hookenv.relation_get()
+    # 'relation_set',           # core.hookenv.relation_set()
+    # 'relation_ids',           # core.hookenv.relation_ids()
+    # 'relation_list',          # core.hookenv.relation_units()
+    # 'config_get',             # core.hookenv.config()
+    # 'unit_get',               # core.hookenv.unit_get()
+    # 'open_port',              # core.hookenv.open_port()
+    # 'close_port',             # core.hookenv.close_port()
+    # 'service_control',        # core.host.service()
+    'unit_info',              # client-side, NOT IMPLEMENTED
+    'wait_for_machine',       # client-side, NOT IMPLEMENTED
+    'wait_for_page_contents',  # client-side, NOT IMPLEMENTED
+    'wait_for_relation',      # client-side, NOT IMPLEMENTED
+    'wait_for_unit',          # client-side, NOT IMPLEMENTED
+]
+
+
+SLEEP_AMOUNT = 0.1
+
+
+# We create a juju_status Command here because it makes testing much,
+# much easier.
+def juju_status():
+    subprocess.check_call(['juju', 'status'])
+
+# re-implemented as charmhelpers.fetch.configure_sources()
+# def configure_source(update=False):
+#    source = config_get('source')
+#    if ((source.startswith('ppa:') or
+#         source.startswith('cloud:') or
+#         source.startswith('http:'))):
+#        run('add-apt-repository', source)
+#    if source.startswith("http:"):
+#        run('apt-key', 'import', config_get('key'))
+#    if update:
+#        run('apt-get', 'update')
+
+
+# DEPRECATED: client-side only
+def make_charm_config_file(charm_config):
+    charm_config_file = tempfile.NamedTemporaryFile(mode='w+')
+    charm_config_file.write(yaml.dump(charm_config))
+    charm_config_file.flush()
+    # The NamedTemporaryFile instance is returned instead of just the name
+    # because we want to take advantage of garbage collection-triggered
+    # deletion of the temp file when it goes out of scope in the caller.
+    return charm_config_file
+
+
+# DEPRECATED: client-side only
+def unit_info(service_name, item_name, data=None, unit=None):
+    if data is None:
+        data = yaml.safe_load(juju_status())
+    service = data['services'].get(service_name)
+    if service is None:
+        # XXX 2012-02-08 gmb:
+        #     This allows us to cope with the race condition that we
+        #     have between deploying a service and having it come up in
+        #     `juju status`. We could probably do with cleaning it up so
+        #     that it fails a bit more noisily after a while.
+        return ''
+    units = service['units']
+    if unit is not None:
+        item = units[unit][item_name]
+    else:
+        # It might seem odd to sort the units here, but we do it to
+        # ensure that when no unit is specified, the first unit for the
+        # service (or at least the one with the lowest number) is the
+        # one whose data gets returned.
+        sorted_unit_names = sorted(units.keys())
+        item = units[sorted_unit_names[0]][item_name]
+    return item
+
+
+# DEPRECATED: client-side only
+def get_machine_data():
+    return yaml.safe_load(juju_status())['machines']
+
+
+# DEPRECATED: client-side only
+def wait_for_machine(num_machines=1, timeout=300):
+    """Wait `timeout` seconds for `num_machines` machines to come up.
+
+    This wait_for... function can be called by other wait_for functions
+    whose timeouts might be too short in situations where only a bare
+    Juju setup has been bootstrapped.
+
+    :return: A tuple of (num_machines, time_taken). This is used for
+             testing.
+    """
+    # You may think this is a hack, and you'd be right. The easiest way
+    # to tell what environment we're working in (LXC vs EC2) is to check
+    # the dns-name of the first machine. If it's localhost we're in LXC
+    # and we can just return here.
+    if get_machine_data()[0]['dns-name'] == 'localhost':
+        return 1, 0
+    start_time = time.time()
+    while True:
+        # Drop the first machine, since it's the Zookeeper and that's
+        # not a machine that we need to wait for. This will only work
+        # for EC2 environments, which is why we return early above if
+        # we're in LXC.
+        machine_data = get_machine_data()
+        non_zookeeper_machines = [
+            machine_data[key] for key in list(machine_data.keys())[1:]]
+        if len(non_zookeeper_machines) >= num_machines:
+            all_machines_running = True
+            for machine in non_zookeeper_machines:
+                if machine.get('instance-state') != 'running':
+                    all_machines_running = False
+                    break
+            if all_machines_running:
+                break
+        if time.time() - start_time >= timeout:
+            raise RuntimeError('timeout waiting for service to start')
+        time.sleep(SLEEP_AMOUNT)
+    return num_machines, time.time() - start_time
+
+
+# DEPRECATED: client-side only
+def wait_for_unit(service_name, timeout=480):
+    """Wait `timeout` seconds for a given service name to come up."""
+    wait_for_machine(num_machines=1)
+    start_time = time.time()
+    while True:
+        state = unit_info(service_name, 'agent-state')
+        if 'error' in state or state == 'started':
+            break
+        if time.time() - start_time >= timeout:
+            raise RuntimeError('timeout waiting for service to start')
+        time.sleep(SLEEP_AMOUNT)
+    if state != 'started':
+        raise RuntimeError('unit did not start, agent-state: ' + state)
+
+
+# DEPRECATED: client-side only
+def wait_for_relation(service_name, relation_name, timeout=120):
+    """Wait `timeout` seconds for a given relation to come up."""
+    start_time = time.time()
+    while True:
+        relation = unit_info(service_name, 'relations').get(relation_name)
+        if relation is not None and relation['state'] == 'up':
+            break
+        if time.time() - start_time >= timeout:
+            raise RuntimeError('timeout waiting for relation to be up')
+        time.sleep(SLEEP_AMOUNT)
+
+
+# DEPRECATED: client-side only
+def wait_for_page_contents(url, contents, timeout=120, validate=None):
+    if validate is None:
+        validate = operator.contains
+    start_time = time.time()
+    while True:
+        try:
+            stream = urlopen(url)
+        except (HTTPError, URLError):
+            pass
+        else:
+            page = stream.read()
+            if validate(page, contents):
+                return page
+        if time.time() - start_time >= timeout:
+            raise RuntimeError('timeout waiting for contents of ' + url)
+        time.sleep(SLEEP_AMOUNT)
 
=== added directory 'hooks/charmhelpers/contrib/charmsupport'
=== added file 'hooks/charmhelpers/contrib/charmsupport/__init__.py'
--- hooks/charmhelpers/contrib/charmsupport/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/charmsupport/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,15 @@
+# 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/>.
 
=== added file 'hooks/charmhelpers/contrib/charmsupport/nrpe.py'
--- hooks/charmhelpers/contrib/charmsupport/nrpe.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/charmsupport/nrpe.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,324 @@
+# 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/>.
+
+"""Compatibility with the nrpe-external-master charm"""
+# Copyright 2012 Canonical Ltd.
+#
+# Authors:
+#  Matthew Wedgwood <[e-mail]>
+
+import subprocess
+import pwd
+import grp
+import os
+import re
+import shlex
+import yaml
+
+from charmhelpers.core.hookenv import (
+    config,
+    local_unit,
+    log,
+    relation_ids,
+    relation_set,
+    relations_of_type,
+)
+
+from charmhelpers.core.host import service
+
+# This module adds compatibility with the nrpe-external-master and plain nrpe
+# subordinate charms. To use it in your charm:
+#
+# 1. Update metadata.yaml
+#
+#   provides:
+#     (...)
+#     nrpe-external-master:
+#       interface: nrpe-external-master
+#       scope: container
+#
+#   and/or
+#
+#   provides:
+#     (...)
+#     local-monitors:
+#       interface: local-monitors
+#       scope: container
+
+#
+# 2. Add the following to config.yaml
+#
+#    nagios_context:
+#      default: "juju"
+#      type: string
+#      description: |
+#        Used by the nrpe subordinate charms.
+#        A string that will be prepended to instance name to set the host name
+#        in nagios. So for instance the hostname would be something like:
+#            juju-myservice-0
+#        If you're running multiple environments with the same services in them
+#        this allows you to differentiate between them.
+#    nagios_servicegroups:
+#      default: ""
+#      type: string
+#      description: |
+#        A comma-separated list of nagios servicegroups.
+#        If left empty, the nagios_context will be used as the servicegroup
+#
+# 3. Add custom checks (Nagios plugins) to files/nrpe-external-master
+#
+# 4. Update your hooks.py with something like this:
+#
+#    from charmsupport.nrpe import NRPE
+#    (...)
+#    def update_nrpe_config():
+#        nrpe_compat = NRPE()
+#        nrpe_compat.add_check(
+#            shortname = "myservice",
+#            description = "Check MyService",
+#            check_cmd = "check_http -w 2 -c 10 http://localhost"
+#            )
+#        nrpe_compat.add_check(
+#            "myservice_other",
+#            "Check for widget failures",
+#            check_cmd = "/srv/myapp/scripts/widget_check"
+#            )
+#        nrpe_compat.write()
+#
+#    def config_changed():
+#        (...)
+#        update_nrpe_config()
+#
+#    def nrpe_external_master_relation_changed():
+#        update_nrpe_config()
+#
+#    def local_monitors_relation_changed():
+#        update_nrpe_config()
+#
+# 5. ln -s hooks.py nrpe-external-master-relation-changed
+#    ln -s hooks.py local-monitors-relation-changed
+
+
+class CheckException(Exception):
+    pass
+
+
+class Check(object):
+    shortname_re = '[A-Za-z0-9-_]+$'
+    service_template = ("""
+#---------------------------------------------------
+# This file is Juju managed
+#---------------------------------------------------
+define service {{
+    use                             active-service
+    host_name                       {nagios_hostname}
+    service_description             {nagios_hostname}[{shortname}] """
+                        """{description}
+    check_command                   check_nrpe!{command}
+    servicegroups                   {nagios_servicegroup}
+}}
+""")
+
+    def __init__(self, shortname, description, check_cmd):
+        super(Check, self).__init__()
+        # XXX: could be better to calculate this from the service name
+        if not re.match(self.shortname_re, shortname):
+            raise CheckException("shortname must match {}".format(
+                Check.shortname_re))
+        self.shortname = shortname
+        self.command = "check_{}".format(shortname)
+        # Note: a set of invalid characters is defined by the
+        # Nagios server config
+        # The default is: illegal_object_name_chars=`~!$%^&*"|'<>?,()=
+        self.description = description
+        self.check_cmd = self._locate_cmd(check_cmd)
+
+    def _locate_cmd(self, check_cmd):
+        search_path = (
+            '/usr/lib/nagios/plugins',
+            '/usr/local/lib/nagios/plugins',
+        )
+        parts = shlex.split(check_cmd)
+        for path in search_path:
+            if os.path.exists(os.path.join(path, parts[0])):
+                command = os.path.join(path, parts[0])
+                if len(parts) > 1:
+                    command += " " + " ".join(parts[1:])
+                return command
+        log('Check command not found: {}'.format(parts[0]))
+        return ''
+
+    def write(self, nagios_context, hostname, nagios_servicegroups=None):
+        nrpe_check_file = '/etc/nagios/nrpe.d/{}.cfg'.format(
+            self.command)
+        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(
+                self.command, self.check_cmd))
+
+        if not os.path.exists(NRPE.nagios_exportdir):
+            log('Not writing service config as {} is not accessible'.format(
+                NRPE.nagios_exportdir))
+        else:
+            self.write_service_config(nagios_context, hostname,
+                                      nagios_servicegroups)
+
+    def write_service_config(self, nagios_context, hostname,
+                             nagios_servicegroups=None):
+        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))
+
+        if not nagios_servicegroups:
+            nagios_servicegroups = nagios_context
+
+        templ_vars = {
+            'nagios_hostname': hostname,
+            'nagios_servicegroup': nagios_servicegroups,
+            'description': self.description,
+            'shortname': self.shortname,
+            'command': self.command,
+        }
+        nrpe_service_text = Check.service_template.format(**templ_vars)
+        nrpe_service_file = '{}/service__{}_{}.cfg'.format(
+            NRPE.nagios_exportdir, hostname, self.command)
+        with open(nrpe_service_file, 'w') as nrpe_service_config:
+            nrpe_service_config.write(str(nrpe_service_text))
+
+    def run(self):
+        subprocess.call(self.check_cmd)
+
+
+class NRPE(object):
+    nagios_logdir = '/var/log/nagios'
+    nagios_exportdir = '/var/lib/nagios/export'
+    nrpe_confdir = '/etc/nagios/nrpe.d'
+
+    def __init__(self, hostname=None):
+        super(NRPE, self).__init__()
+        self.config = config()
+        self.nagios_context = self.config['nagios_context']
+        if 'nagios_servicegroups' in self.config:
+            self.nagios_servicegroups = self.config['nagios_servicegroups']
+        else:
+            self.nagios_servicegroups = 'juju'
+        self.unit_name = local_unit().replace('/', '-')
+        if hostname:
+            self.hostname = 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 write(self):
+        try:
+            nagios_uid = pwd.getpwnam('nagios').pw_uid
+            nagios_gid = grp.getgrnam('nagios').gr_gid
+        except:
+            log("Nagios user not set up, nrpe checks not updated")
+            return
+
+        if not os.path.exists(NRPE.nagios_logdir):
+            os.mkdir(NRPE.nagios_logdir)
+            os.chown(NRPE.nagios_logdir, nagios_uid, nagios_gid)
+
+        nrpe_monitors = {}
+        monitors = {"monitors": {"remote": {"nrpe": nrpe_monitors}}}
+        for nrpecheck in self.checks:
+            nrpecheck.write(self.nagios_context, self.hostname,
+                            self.nagios_servicegroups)
+            nrpe_monitors[nrpecheck.shortname] = {
+                "command": nrpecheck.command,
+            }
+
+        service('restart', 'nagios-nrpe-server')
+
+        for rid in relation_ids("local-monitors"):
+            relation_set(relation_id=rid, monitors=yaml.dump(monitors))
+
+
+def get_nagios_hostcontext(relation_name='nrpe-external-master'):
+    """
+    Query relation with nrpe subordinate, return the nagios_host_context
+
+    :param str relation_name: Name of relation nrpe sub joined to
+    """
+    for rel in relations_of_type(relation_name):
+        if 'nagios_hostname' in rel:
+            return rel['nagios_host_context']
+
+
+def get_nagios_hostname(relation_name='nrpe-external-master'):
+    """
+    Query relation with nrpe subordinate, return the nagios_hostname
+
+    :param str relation_name: Name of relation nrpe sub joined to
+    """
+    for rel in relations_of_type(relation_name):
+        if 'nagios_hostname' in rel:
+            return rel['nagios_hostname']
+
+
+def get_nagios_unit_name(relation_name='nrpe-external-master'):
+    """
+    Return the nagios unit name prepended with host_context if needed
+
+    :param str relation_name: Name of relation nrpe sub joined to
+    """
+    host_context = get_nagios_hostcontext(relation_name)
+    if host_context:
+        unit = "%s:%s" % (host_context, local_unit())
+    else:
+        unit = local_unit()
+    return unit
+
+
+def add_init_service_checks(nrpe, services, unit_name):
+    """
+    Add checks for each service in list
+
+    :param NRPE nrpe: NRPE object to add check to
+    :param list services: List of services to check
+    :param str unit_name: Unit name to use in check description
+    """
+    for svc in services:
+        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
+            )
+        elif os.path.exists(sysv_init):
+            cronpath = '/etc/cron.d/nagios-service-check-%s' % svc
+            cron_file = ('*/5 * * * * root '
+                         '/usr/local/lib/nagios/plugins/check_exit_status.pl '
+                         '-s /etc/init.d/%s status > '
+                         '/var/lib/nagios/service-check-%s.txt\n' % (svc,
+                                                                     svc)
+                         )
+            f = open(cronpath, 'w')
+            f.write(cron_file)
+            f.close()
+            nrpe.add_check(
+                shortname=svc,
+                description='process check {%s}' % unit_name,
+                check_cmd='check_status_file.py -f '
+                          '/var/lib/nagios/service-check-%s.txt' % svc,
+            )
 
=== added file 'hooks/charmhelpers/contrib/charmsupport/volumes.py'
--- hooks/charmhelpers/contrib/charmsupport/volumes.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/charmsupport/volumes.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,175 @@
+# 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/>.
+
+'''
+Functions for managing volumes in juju units. One volume is supported per unit.
+Subordinates may have their own storage, provided it is on its own partition.
+
+Configuration stanzas::
+
+  volume-ephemeral:
+    type: boolean
+    default: true
+    description: >
+      If false, a volume is mounted as sepecified in "volume-map"
+      If true, ephemeral storage will be used, meaning that log data
+         will only exist as long as the machine. YOU HAVE BEEN WARNED.
+  volume-map:
+    type: string
+    default: {}
+    description: >
+      YAML map of units to device names, e.g:
+        "{ rsyslog/0: /dev/vdb, rsyslog/1: /dev/vdb }"
+      Service units will raise a configure-error if volume-ephemeral
+      is 'true' and no volume-map value is set. Use 'juju set' to set a
+      value and 'juju resolved' to complete configuration.
+
+Usage::
+
+    from charmsupport.volumes import configure_volume, VolumeConfigurationError
+    from charmsupport.hookenv import log, ERROR
+    def post_mount_hook():
+        stop_service('myservice')
+    def post_mount_hook():
+        start_service('myservice')
+
+    if __name__ == '__main__':
+        try:
+            configure_volume(before_change=pre_mount_hook,
+                             after_change=post_mount_hook)
+        except VolumeConfigurationError:
+            log('Storage could not be configured', ERROR)
+
+'''
+
+# XXX: Known limitations
+# - fstab is neither consulted nor updated
+
+import os
+from charmhelpers.core import hookenv
+from charmhelpers.core import host
+import yaml
+
+
+MOUNT_BASE = '/srv/juju/volumes'
+
+
+class VolumeConfigurationError(Exception):
+    '''Volume configuration data is missing or invalid'''
+    pass
+
+
+def get_config():
+    '''Gather and sanity-check volume configuration data'''
+    volume_config = {}
+    config = hookenv.config()
+
+    errors = False
+
+    if config.get('volume-ephemeral') in (True, 'True', 'true', 'Yes', 'yes'):
+        volume_config['ephemeral'] = True
+    else:
+        volume_config['ephemeral'] = False
+
+    try:
+        volume_map = yaml.safe_load(config.get('volume-map', '{}'))
+    except yaml.YAMLError as e:
+        hookenv.log("Error parsing YAML volume-map: {}".format(e),
+                    hookenv.ERROR)
+        errors = True
+    if volume_map is None:
+        # probably an empty string
+        volume_map = {}
+    elif not isinstance(volume_map, dict):
+        hookenv.log("Volume-map should be a dictionary, not {}".format(
+            type(volume_map)))
+        errors = True
+
+    volume_config['device'] = volume_map.get(os.environ['JUJU_UNIT_NAME'])
+    if volume_config['device'] and volume_config['ephemeral']:
+        # asked for ephemeral storage but also defined a volume ID
+        hookenv.log('A volume is defined for this unit, but ephemeral '
+                    'storage was requested', hookenv.ERROR)
+        errors = True
+    elif not volume_config['device'] and not volume_config['ephemeral']:
+        # asked for permanent storage but did not define volume ID
+        hookenv.log('Ephemeral storage was requested, but there is no volume '
+                    'defined for this unit.', hookenv.ERROR)
+        errors = True
+
+    unit_mount_name = hookenv.local_unit().replace('/', '-')
+    volume_config['mountpoint'] = os.path.join(MOUNT_BASE, unit_mount_name)
+
+    if errors:
+        return None
+    return volume_config
+
+
+def mount_volume(config):
+    if os.path.exists(config['mountpoint']):
+        if not os.path.isdir(config['mountpoint']):
+            hookenv.log('Not a directory: {}'.format(config['mountpoint']))
+            raise VolumeConfigurationError()
+    else:
+        host.mkdir(config['mountpoint'])
+    if os.path.ismount(config['mountpoint']):
+        unmount_volume(config)
+    if not host.mount(config['device'], config['mountpoint'], persist=True):
+        raise VolumeConfigurationError()
+
+
+def unmount_volume(config):
+    if os.path.ismount(config['mountpoint']):
+        if not host.umount(config['mountpoint'], persist=True):
+            raise VolumeConfigurationError()
+
+
+def managed_mounts():
+    '''List of all mounted managed volumes'''
+    return filter(lambda mount: mount[0].startswith(MOUNT_BASE), host.mounts())
+
+
+def configure_volume(before_change=lambda: None, after_change=lambda: None):
+    '''Set up storage (or don't) according to the charm's volume configuration.
+       Returns the mount point or "ephemeral". before_change and after_change
+       are optional functions to be called if the volume configuration changes.
+    '''
+
+    config = get_config()
+    if not config:
+        hookenv.log('Failed to read volume configuration', hookenv.CRITICAL)
+        raise VolumeConfigurationError()
+
+    if config['ephemeral']:
+        if os.path.ismount(config['mountpoint']):
+            before_change()
+            unmount_volume(config)
+            after_change()
+        return 'ephemeral'
+    else:
+        # persistent storage
+        if os.path.ismount(config['mountpoint']):
+            mounts = dict(managed_mounts())
+            if mounts.get(config['mountpoint']) != config['device']:
+                before_change()
+                unmount_volume(config)
+                mount_volume(config)
+                after_change()
+        else:
+            before_change()
+            mount_volume(config)
+            after_change()
+        return config['mountpoint']
 
=== added directory 'hooks/charmhelpers/contrib/database'
=== added file 'hooks/charmhelpers/contrib/database/__init__.py'
=== added file 'hooks/charmhelpers/contrib/database/mysql.py'
--- hooks/charmhelpers/contrib/database/mysql.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/database/mysql.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,372 @@
+"""Helper for working with a MySQL database"""
+import json
+import socket
+import re
+import sys
+import platform
+import os
+import glob
+
+from string import upper
+
+from charmhelpers.core.host import (
+    mkdir,
+    pwgen,
+    write_file
+)
+from charmhelpers.core.hookenv import (
+    relation_get,
+    related_units,
+    unit_get,
+    log,
+    DEBUG,
+    INFO,
+)
+from charmhelpers.core.hookenv import config as config_get
+from charmhelpers.fetch import (
+    apt_install,
+    apt_update,
+    filter_installed_packages,
+)
+from charmhelpers.contrib.peerstorage import (
+    peer_store,
+    peer_retrieve,
+)
+
+try:
+    import MySQLdb
+except ImportError:
+    apt_update(fatal=True)
+    apt_install(filter_installed_packages(['python-mysqldb']), fatal=True)
+    import MySQLdb
+
+
+class MySQLHelper(object):
+
+    def __init__(self, rpasswdf_template, upasswdf_template, host='localhost'):
+        self.host = host
+        # Password file path templates
+        self.root_passwd_file_template = rpasswdf_template
+        self.user_passwd_file_template = upasswdf_template
+
+    def connect(self, user='root', password=None):
+        self.connection = MySQLdb.connect(user=user, host=self.host,
+                                          passwd=password)
+
+    def database_exists(self, db_name):
+        cursor = self.connection.cursor()
+        try:
+            cursor.execute("SHOW DATABASES")
+            databases = [i[0] for i in cursor.fetchall()]
+        finally:
+            cursor.close()
+
+        return db_name in databases
+
+    def create_database(self, db_name):
+        cursor = self.connection.cursor()
+        try:
+            cursor.execute("CREATE DATABASE {} CHARACTER SET UTF8"
+                           .format(db_name))
+        finally:
+            cursor.close()
+
+    def grant_exists(self, db_name, db_user, remote_ip):
+        cursor = self.connection.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))
+            grants = [i[0] for i in cursor.fetchall()]
+        except MySQLdb.OperationalError:
+            return False
+        finally:
+            cursor.close()
+
+        # TODO: review for different grants
+        return priv_string in grants
+
+    def create_grant(self, db_name, db_user, remote_ip, password):
+        cursor = self.connection.cursor()
+        try:
+            # TODO: review for different grants
+            cursor.execute("GRANT ALL PRIVILEGES ON {}.* TO '{}'@'{}' "
+                           "IDENTIFIED BY '{}'".format(db_name,
+                                                       db_user,
+                                                       remote_ip,
+                                                       password))
+        finally:
+            cursor.close()
+
+    def create_admin_grant(self, db_user, remote_ip, password):
+        cursor = self.connection.cursor()
+        try:
+            cursor.execute("GRANT ALL PRIVILEGES ON *.* TO '{}'@'{}' "
+                           "IDENTIFIED BY '{}'".format(db_user,
+                                                       remote_ip,
+                                                       password))
+        finally:
+            cursor.close()
+
+    def cleanup_grant(self, db_user, remote_ip):
+        cursor = self.connection.cursor()
+        try:
+            cursor.execute("DROP FROM mysql.user WHERE user='{}' "
+                           "AND HOST='{}'".format(db_user,
+                                                  remote_ip))
+        finally:
+            cursor.close()
+
+    def execute(self, sql):
+        """Execute arbitary SQL against the database."""
+        cursor = self.connection.cursor()
+        try:
+            cursor.execute(sql)
+        finally:
+            cursor.close()
+
+    def migrate_passwords_to_peer_relation(self):
+        """Migrate any passwords storage on disk to cluster peer relation."""
+        dirname = os.path.dirname(self.root_passwd_file_template)
+        path = os.path.join(dirname, '*.passwd')
+        for f in glob.glob(path):
+            _key = os.path.basename(f)
+            with open(f, 'r') as passwd:
+                _value = passwd.read().strip()
+
+            try:
+                peer_store(_key, _value)
+                os.unlink(f)
+            except ValueError:
+                # NOTE cluster relation not yet ready - skip for now
+                pass
+
+    def get_mysql_password_on_disk(self, username=None, password=None):
+        """Retrieve, generate or store a mysql password for the provided
+        username on disk."""
+        if username:
+            template = self.user_passwd_file_template
+            passwd_file = template.format(username)
+        else:
+            passwd_file = self.root_passwd_file_template
+
+        _password = None
+        if os.path.exists(passwd_file):
+            with open(passwd_file, 'r') as passwd:
+                _password = passwd.read().strip()
+        else:
+            mkdir(os.path.dirname(passwd_file), owner='root', group='root',
+                  perms=0o770)
+            # Force permissions - for some reason the chmod in makedirs fails
+            os.chmod(os.path.dirname(passwd_file), 0o770)
+            _password = password or pwgen(length=32)
+            write_file(passwd_file, _password, owner='root', group='root',
+                       perms=0o660)
+
+        return _password
+
+    def get_mysql_password(self, username=None, password=None):
+        """Retrieve, generate or store a mysql password for the provided
+        username using peer relation cluster."""
+        self.migrate_passwords_to_peer_relation()
+        if username:
+            _key = 'mysql-{}.passwd'.format(username)
+        else:
+            _key = 'mysql.passwd'
+
+        try:
+            _password = peer_retrieve(_key)
+            if _password is None:
+                _password = password or pwgen(length=32)
+                peer_store(_key, _password)
+        except ValueError:
+            # cluster relation is not yet started; use on-disk
+            _password = self.get_mysql_password_on_disk(username, password)
+
+        return _password
+
+    def get_mysql_root_password(self, password=None):
+        """Retrieve or generate mysql root password for service units."""
+        return self.get_mysql_password(username=None, password=password)
+
+    def get_allowed_units(self, database, username, relation_id=None):
+        """Get list of units with access grants for database with username.
+
+        This is typically used to provide shared-db relations with a list of
+        which units have been granted access to the given database.
+        """
+        self.connect(password=self.get_mysql_root_password())
+        allowed_units = set()
+        for unit in related_units(relation_id):
+            settings = relation_get(rid=relation_id, unit=unit)
+            # First check for setting with prefix, then without
+            for attr in ["%s_hostname" % (database), 'hostname']:
+                hosts = settings.get(attr, None)
+                if hosts:
+                    break
+
+            if hosts:
+                # hostname can be json-encoded list of hostnames
+                try:
+                    hosts = json.loads(hosts)
+                except ValueError:
+                    hosts = [hosts]
+            else:
+                hosts = [settings['private-address']]
+
+            if hosts:
+                for host in hosts:
+                    if self.grant_exists(database, username, host):
+                        log("Grant exists for host '%s' on db '%s'" %
+                            (host, database), level=DEBUG)
+                        if unit not in allowed_units:
+                            allowed_units.add(unit)
+                    else:
+                        log("Grant does NOT exist for host '%s' on db '%s'" %
+                            (host, database), level=DEBUG)
+            else:
+                log("No hosts found for grant check", level=INFO)
+
+        return allowed_units
+
+    def configure_db(self, hostname, database, username, admin=False):
+        """Configure access to database for username from hostname."""
+        if config_get('prefer-ipv6'):
+            remote_ip = hostname
+        elif hostname != unit_get('private-address'):
+            try:
+                remote_ip = socket.gethostbyname(hostname)
+            except Exception:
+                # socket.gethostbyname doesn't support ipv6
+                remote_ip = hostname
+        else:
+            remote_ip = '127.0.0.1'
+
+        self.connect(password=self.get_mysql_root_password())
+        if not self.database_exists(database):
+            self.create_database(database)
+
+        password = self.get_mysql_password(username)
+        if not self.grant_exists(database, username, remote_ip):
+            if not admin:
+                self.create_grant(database, username, remote_ip, password)
+            else:
+                self.create_admin_grant(username, remote_ip, password)
+
+        return password
+
+
+class PerconaClusterHelper(object):
+
+    # Going for the biggest page size to avoid wasted bytes. InnoDB page size is
+    # 16MB
+    DEFAULT_PAGE_SIZE = 16 * 1024 * 1024
+
+    def human_to_bytes(self, human):
+        """Convert human readable configuration options to bytes."""
+        num_re = re.compile('^[0-9]+$')
+        if num_re.match(human):
+            return human
+
+        factors = {
+            'K': 1024,
+            'M': 1048576,
+            'G': 1073741824,
+            'T': 1099511627776
+        }
+        modifier = human[-1]
+        if modifier in factors:
+            return int(human[:-1]) * factors[modifier]
+
+        if modifier == '%':
+            total_ram = self.human_to_bytes(self.get_mem_total())
+            if self.is_32bit_system() and total_ram > self.sys_mem_limit():
+                total_ram = self.sys_mem_limit()
+            factor = int(human[:-1]) * 0.01
+            pctram = total_ram * factor
+            return int(pctram - (pctram % self.DEFAULT_PAGE_SIZE))
+
+        raise ValueError("Can only convert K,M,G, or T")
+
+    def is_32bit_system(self):
+        """Determine whether system is 32 or 64 bit."""
+        try:
+            return sys.maxsize < 2 ** 32
+        except OverflowError:
+            return False
+
+    def sys_mem_limit(self):
+        """Determine the default memory limit for the current service unit."""
+        if platform.machine() in ['armv7l']:
+            _mem_limit = self.human_to_bytes('2700M')  # experimentally determined
+        else:
+            # Limit for x86 based 32bit systems
+            _mem_limit = self.human_to_bytes('4G')
+
+        return _mem_limit
+
+    def get_mem_total(self):
+        """Calculate the total memory in the current service unit."""
+        with open('/proc/meminfo') as meminfo_file:
+            for line in meminfo_file:
+                key, mem = line.split(':', 2)
+                if key == 'MemTotal':
+                    mtot, modifier = mem.strip().split(' ')
+                    return '%s%s' % (mtot, upper(modifier[0]))
+
+    def parse_config(self):
+        """Parse charm configuration and calculate values for config files."""
+        config = config_get()
+        mysql_config = {}
+        if 'max-connections' in config:
+            mysql_config['max_connections'] = config['max-connections']
+
+        # Total memory available for dataset
+        dataset_bytes = self.human_to_bytes(config['dataset-size'])
+        mysql_config['dataset_bytes'] = dataset_bytes
+
+        if 'query-cache-type' in config:
+            # Query Cache Configuration
+            mysql_config['query_cache_size'] = config['query-cache-size']
+            if (config['query-cache-size'] == -1 and
+                    config['query-cache-type'] in ['ON', 'DEMAND']):
+                # Calculate the query cache size automatically
+                qcache_bytes = (dataset_bytes * 0.20)
+                qcache_bytes = int(qcache_bytes -
+                                   (qcache_bytes % self.DEFAULT_PAGE_SIZE))
+                mysql_config['query_cache_size'] = qcache_bytes
+                dataset_bytes -= qcache_bytes
+
+            # 5.5 allows the words, but not 5.1
+            if config['query-cache-type'] == 'ON':
+                mysql_config['query_cache_type'] = 1
+            elif config['query-cache-type'] == 'DEMAND':
+                mysql_config['query_cache_type'] = 2
+            else:
+                mysql_config['query_cache_type'] = 0
+
+        # Set a sane default key_buffer size
+        mysql_config['key_buffer'] = self.human_to_bytes('32M')
+
+        if 'preferred-storage-engine' in config:
+            # Storage engine configuration
+            preferred_engines = config['preferred-storage-engine'].split(',')
+            chunk_size = int(dataset_bytes / len(preferred_engines))
+            mysql_config['innodb_flush_log_at_trx_commit'] = 1
+            mysql_config['sync_binlog'] = 1
+            if 'InnoDB' in preferred_engines:
+                mysql_config['innodb_buffer_pool_size'] = chunk_size
+                if config['tuning-level'] == 'fast':
+                    mysql_config['innodb_flush_log_at_trx_commit'] = 2
+            else:
+                mysql_config['innodb_buffer_pool_size'] = 0
+
+            mysql_config['default_storage_engine'] = preferred_engines[0]
+            if 'MyISAM' in preferred_engines:
+                mysql_config['key_buffer'] = chunk_size
+
+            if config['tuning-level'] == 'fast':
+                mysql_config['sync_binlog'] = 0
+
+        return mysql_config
 
=== added directory 'hooks/charmhelpers/contrib/hahelpers'
=== added file 'hooks/charmhelpers/contrib/hahelpers/__init__.py'
--- hooks/charmhelpers/contrib/hahelpers/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/hahelpers/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,15 @@
+# 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/>.
 
=== added file 'hooks/charmhelpers/contrib/hahelpers/apache.py'
--- hooks/charmhelpers/contrib/hahelpers/apache.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/hahelpers/apache.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,82 @@
+# 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/>.
+
+#
+# Copyright 2012 Canonical Ltd.
+#
+# This file is sourced from lp:openstack-charm-helpers
+#
+# Authors:
+#  James Page <[e-mail]>
+#  Adam Gandelman <[e-mail]>
+#
+
+import subprocess
+
+from charmhelpers.core.hookenv import (
+    config as config_get,
+    relation_get,
+    relation_ids,
+    related_units as relation_list,
+    log,
+    INFO,
+)
+
+
+def get_cert(cn=None):
+    # TODO: deal with multiple https endpoints via charm config
+    cert = config_get('ssl_cert')
+    key = config_get('ssl_key')
+    if not (cert and key):
+        log("Inspecting identity-service relations for SSL certificate.",
+            level=INFO)
+        cert = key = None
+        if cn:
+            ssl_cert_attr = 'ssl_cert_{}'.format(cn)
+            ssl_key_attr = 'ssl_key_{}'.format(cn)
+        else:
+            ssl_cert_attr = 'ssl_cert'
+            ssl_key_attr = 'ssl_key'
+        for r_id in relation_ids('identity-service'):
+            for unit in relation_list(r_id):
+                if not cert:
+                    cert = relation_get(ssl_cert_attr,
+                                        rid=r_id, unit=unit)
+                if not key:
+                    key = relation_get(ssl_key_attr,
+                                       rid=r_id, unit=unit)
+    return (cert, key)
+
+
+def get_ca_cert():
+    ca_cert = config_get('ssl_ca')
+    if ca_cert is None:
+        log("Inspecting identity-service relations for CA SSL certificate.",
+            level=INFO)
+        for r_id in relation_ids('identity-service'):
+            for unit in relation_list(r_id):
+                if ca_cert is None:
+                    ca_cert = relation_get('ca_cert',
+                                           rid=r_id, unit=unit)
+    return ca_cert
+
+
+def install_ca_cert(ca_cert):
+    if ca_cert:
+        with open('/usr/local/share/ca-certificates/keystone_juju_ca_cert.crt',
+                  'w') as crt:
+            crt.write(ca_cert)
+        subprocess.check_call(['update-ca-certificates', '--fresh'])
 
=== added file 'hooks/charmhelpers/contrib/hahelpers/cluster.py'
--- hooks/charmhelpers/contrib/hahelpers/cluster.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/hahelpers/cluster.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,268 @@
+# 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/>.
+
+#
+# Copyright 2012 Canonical Ltd.
+#
+# Authors:
+#  James Page <[e-mail]>
+#  Adam Gandelman <[e-mail]>
+#
+
+"""
+Helpers for clustering and determining "cluster leadership" and other
+clustering-related helpers.
+"""
+
+import subprocess
+import os
+
+from socket import gethostname as get_unit_hostname
+
+import six
+
+from charmhelpers.core.hookenv import (
+    log,
+    relation_ids,
+    related_units as relation_list,
+    relation_get,
+    config as config_get,
+    INFO,
+    ERROR,
+    WARNING,
+    unit_get,
+)
+from charmhelpers.core.decorators import (
+    retry_on_exception,
+)
+
+
+class HAIncompleteConfig(Exception):
+    pass
+
+
+class CRMResourceNotFound(Exception):
+    pass
+
+
+def is_elected_leader(resource):
+    """
+    Returns True if the charm executing this is the elected cluster leader.
+
+    It relies on two mechanisms to determine leadership:
+        1. If the charm is part of a corosync cluster, call corosync to
+        determine leadership.
+        2. If the charm is not part of a corosync cluster, the leader is
+        determined as being "the alive unit with the lowest unit numer". In
+        other words, the oldest surviving unit.
+    """
+    if is_clustered():
+        if not is_crm_leader(resource):
+            log('Deferring action to CRM leader.', level=INFO)
+            return False
+    else:
+        peers = peer_units()
+        if peers and not oldest_peer(peers):
+            log('Deferring action to oldest service unit.', level=INFO)
+            return False
+    return True
+
+
+def is_clustered():
+    for r_id in (relation_ids('ha') or []):
+        for unit in (relation_list(r_id) or []):
+            clustered = relation_get('clustered',
+                                     rid=r_id,
+                                     unit=unit)
+            if clustered:
+                return True
+    return False
+
+
+@retry_on_exception(5, base_delay=2, exc_type=CRMResourceNotFound)
+def is_crm_leader(resource, retry=False):
+    """
+    Returns True if the charm calling this is the elected corosync leader,
+    as returned by calling the external "crm" command.
+
+    We allow this operation to be retried to avoid the possibility of getting a
+    false negative. See LP #1396246 for more info.
+    """
+    cmd = ['crm', 'resource', 'show', resource]
+    try:
+        status = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
+        if not isinstance(status, six.text_type):
+            status = six.text_type(status, "utf-8")
+    except subprocess.CalledProcessError:
+        status = None
+
+    if status and get_unit_hostname() in status:
+        return True
+
+    if status and "resource %s is NOT running" % (resource) in status:
+        raise CRMResourceNotFound("CRM resource %s not found" % (resource))
+
+    return False
+
+
+def is_leader(resource):
+    log("is_leader is deprecated. Please consider using is_crm_leader "
+        "instead.", level=WARNING)
+    return is_crm_leader(resource)
+
+
+def peer_units(peer_relation="cluster"):
+    peers = []
+    for r_id in (relation_ids(peer_relation) or []):
+        for unit in (relation_list(r_id) or []):
+            peers.append(unit)
+    return peers
+
+
+def peer_ips(peer_relation='cluster', addr_key='private-address'):
+    '''Return a dict of peers and their private-address'''
+    peers = {}
+    for r_id in relation_ids(peer_relation):
+        for unit in relation_list(r_id):
+            peers[unit] = relation_get(addr_key, rid=r_id, unit=unit)
+    return peers
+
+
+def oldest_peer(peers):
+    """Determines who the oldest peer is by comparing unit numbers."""
+    local_unit_no = int(os.getenv('JUJU_UNIT_NAME').split('/')[1])
+    for peer in peers:
+        remote_unit_no = int(peer.split('/')[1])
+        if remote_unit_no < local_unit_no:
+            return False
+    return True
+
+
+def eligible_leader(resource):
+    log("eligible_leader is deprecated. Please consider using "
+        "is_elected_leader instead.", level=WARNING)
+    return is_elected_leader(resource)
+
+
+def https():
+    '''
+    Determines whether enough data has been provided in configuration
+    or relation data to configure HTTPS
+    .
+    returns: boolean
+    '''
+    if config_get('use-https') == "yes":
+        return True
+    if config_get('ssl_cert') and config_get('ssl_key'):
+        return True
+    for r_id in relation_ids('identity-service'):
+        for unit in relation_list(r_id):
+            # TODO - needs fixing for new helper as ssl_cert/key suffixes with CN
+            rel_state = [
+                relation_get('https_keystone', rid=r_id, unit=unit),
+                relation_get('ca_cert', rid=r_id, unit=unit),
+            ]
+            # NOTE: works around (LP: #1203241)
+            if (None not in rel_state) and ('' not in rel_state):
+                return True
+    return False
+
+
+def determine_api_port(public_port, singlenode_mode=False):
+    '''
+    Determine correct API server listening port based on
+    existence of HTTPS reverse proxy and/or haproxy.
+
+    public_port: int: standard public port for given service
+
+    singlenode_mode: boolean: Shuffle ports when only a single unit is present
+
+    returns: int: the correct listening port for the API service
+    '''
+    i = 0
+    if singlenode_mode:
+        i += 1
+    elif len(peer_units()) > 0 or is_clustered():
+        i += 1
+    if https():
+        i += 1
+    return public_port - (i * 10)
+
+
+def determine_apache_port(public_port, singlenode_mode=False):
+    '''
+    Description: Determine correct apache listening port based on public IP +
+    state of the cluster.
+
+    public_port: int: standard public port for given service
+
+    singlenode_mode: boolean: Shuffle ports when only a single unit is present
+
+    returns: int: the correct listening port for the HAProxy service
+    '''
+    i = 0
+    if singlenode_mode:
+        i += 1
+    elif len(peer_units()) > 0 or is_clustered():
+        i += 1
+    return public_port - (i * 10)
+
+
+def get_hacluster_config(exclude_keys=None):
+    '''
+    Obtains all relevant configuration from charm configuration required
+    for initiating a relation to hacluster:
+
+        ha-bindiface, ha-mcastport, vip
+
+    param: exclude_keys: list of setting key(s) to be excluded.
+    returns: dict: A dict containing settings keyed by setting name.
+    raises: HAIncompleteConfig if settings are missing.
+    '''
+    settings = ['ha-bindiface', 'ha-mcastport', 'vip']
+    conf = {}
+    for setting in settings:
+        if exclude_keys and setting in exclude_keys:
+            continue
+
+        conf[setting] = config_get(setting)
+    missing = []
+    [missing.append(s) for s, v in six.iteritems(conf) if v is None]
+    if missing:
+        log('Insufficient config data to configure hacluster.', level=ERROR)
+        raise HAIncompleteConfig
+    return conf
+
+
+def canonical_url(configs, vip_setting='vip'):
+    '''
+    Returns the correct HTTP URL to this host given the state of HTTPS
+    configuration and hacluster.
+
+    :configs    : OSTemplateRenderer: A config tempating object to inspect for
+                                      a complete https context.
+
+    :vip_setting:                str: Setting in charm config that specifies
+                                      VIP address.
+    '''
+    scheme = 'http'
+    if 'https' in configs.complete_contexts():
+        scheme = 'https'
+    if is_clustered():
+        addr = config_get(vip_setting)
+    else:
+        addr = unit_get('private-address')
+    return '%s://%s' % (scheme, addr)
 
=== added directory 'hooks/charmhelpers/contrib/network'
=== added file 'hooks/charmhelpers/contrib/network/__init__.py'
--- hooks/charmhelpers/contrib/network/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/network/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,15 @@
+# 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/>.
 
=== 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	2015-06-18 17:19:58 +0000
@@ -0,0 +1,367 @@
+# 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 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 directory 'hooks/charmhelpers/contrib/network/ovs'
=== added file 'hooks/charmhelpers/contrib/network/ovs/__init__.py'
--- hooks/charmhelpers/contrib/network/ovs/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/network/ovs/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,96 @@
+# 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/>.
+
+''' Helpers for interacting with OpenvSwitch '''
+import subprocess
+import os
+from charmhelpers.core.hookenv import (
+    log, WARNING
+)
+from charmhelpers.core.host import (
+    service
+)
+
+
+def add_bridge(name):
+    ''' Add the named bridge to openvswitch '''
+    log('Creating bridge {}'.format(name))
+    subprocess.check_call(["ovs-vsctl", "--", "--may-exist", "add-br", name])
+
+
+def del_bridge(name):
+    ''' Delete the named bridge from openvswitch '''
+    log('Deleting bridge {}'.format(name))
+    subprocess.check_call(["ovs-vsctl", "--", "--if-exists", "del-br", name])
+
+
+def add_bridge_port(name, port, promisc=False):
+    ''' Add a port to the named openvswitch bridge '''
+    log('Adding port {} to bridge {}'.format(port, name))
+    subprocess.check_call(["ovs-vsctl", "--", "--may-exist", "add-port",
+                           name, port])
+    subprocess.check_call(["ip", "link", "set", port, "up"])
+    if promisc:
+        subprocess.check_call(["ip", "link", "set", port, "promisc", "on"])
+    else:
+        subprocess.check_call(["ip", "link", "set", port, "promisc", "off"])
+
+
+def del_bridge_port(name, port):
+    ''' Delete a port from the named openvswitch bridge '''
+    log('Deleting port {} from bridge {}'.format(port, name))
+    subprocess.check_call(["ovs-vsctl", "--", "--if-exists", "del-port",
+                           name, port])
+    subprocess.check_call(["ip", "link", "set", port, "down"])
+    subprocess.check_call(["ip", "link", "set", port, "promisc", "off"])
+
+
+def set_manager(manager):
+    ''' Set the controller for the local openvswitch '''
+    log('Setting manager for local ovs to {}'.format(manager))
+    subprocess.check_call(['ovs-vsctl', 'set-manager',
+                           'ssl:{}'.format(manager)])
+
+
+CERT_PATH = '/etc/openvswitch/ovsclient-cert.pem'
+
+
+def get_certificate():
+    ''' Read openvswitch certificate from disk '''
+    if os.path.exists(CERT_PATH):
+        log('Reading ovs certificate from {}'.format(CERT_PATH))
+        with open(CERT_PATH, 'r') as cert:
+            full_cert = cert.read()
+            begin_marker = "-----BEGIN CERTIFICATE-----"
+            end_marker = "-----END CERTIFICATE-----"
+            begin_index = full_cert.find(begin_marker)
+            end_index = full_cert.rfind(end_marker)
+            if end_index == -1 or begin_index == -1:
+                raise RuntimeError("Certificate does not contain valid begin"
+                                   " and end markers.")
+            full_cert = full_cert[begin_index:(end_index + len(end_marker))]
+            return full_cert
+    else:
+        log('Certificate not found', level=WARNING)
+        return None
+
+
+def full_restart():
+    ''' Full restart and reload of openvswitch '''
+    if os.path.exists('/etc/init/openvswitch-force-reload-kmod.conf'):
+        service('start', 'openvswitch-force-reload-kmod')
+    else:
+        service('force-reload-kmod', 'openvswitch-switch')
 
=== added file 'hooks/charmhelpers/contrib/network/ufw.py'
--- hooks/charmhelpers/contrib/network/ufw.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/network/ufw.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,276 @@
+# 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/>.
+
+"""
+This module contains helpers to add and remove ufw rules.
+
+Examples:
+
+- open SSH port for subnet 10.0.3.0/24:
+
+  >>> from charmhelpers.contrib.network import ufw
+  >>> ufw.enable()
+  >>> ufw.grant_access(src='10.0.3.0/24', dst='any', port='22', proto='tcp')
+
+- open service by name as defined in /etc/services:
+
+  >>> from charmhelpers.contrib.network import ufw
+  >>> ufw.enable()
+  >>> ufw.service('ssh', 'open')
+
+- close service by port number:
+
+  >>> from charmhelpers.contrib.network import ufw
+  >>> ufw.enable()
+  >>> ufw.service('4949', 'close')  # munin
+"""
+import re
+import os
+import subprocess
+from charmhelpers.core import hookenv
+
+__author__ = "Felipe Reyes <[e-mail]>"
+
+
+class UFWError(Exception):
+    pass
+
+
+class UFWIPv6Error(UFWError):
+    pass
+
+
+def is_enabled():
+    """
+    Check if `ufw` is enabled
+
+    :returns: True if ufw is enabled
+    """
+    output = subprocess.check_output(['ufw', 'status'],
+                                     universal_newlines=True,
+                                     env={'LANG': 'en_US',
+                                          'PATH': os.environ['PATH']})
+
+    m = re.findall(r'^Status: active\n', output, re.M)
+
+    return len(m) >= 1
+
+
+def is_ipv6_ok(soft_fail=False):
+    """
+    Check if IPv6 support is present and ip6tables functional
+
+    :param soft_fail: If set to True and IPv6 support is broken, then reports
+                      that the host doesn't have IPv6 support, otherwise a
+                      UFWIPv6Error exception is raised.
+    :returns: True if IPv6 is working, False otherwise
+    """
+
+    # 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:
+            # 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
+                return True
+            except subprocess.CalledProcessError as ex:
+                hookenv.log("Couldn't load ip6_tables module: %s" % ex.output,
+                            level="WARN")
+                # we are in a world where ip6tables isn't working
+                if soft_fail:
+                    # so we inform that the machine doesn't have IPv6
+                    return False
+                else:
+                    raise UFWIPv6Error("IPv6 firewall support broken")
+        else:
+            # the module is present :)
+            return True
+
+    else:
+        # the system doesn't have IPv6
+        return False
+
+
+def disable_ipv6():
+    """
+    Disable ufw IPv6 support in /etc/default/ufw
+    """
+    exit_code = subprocess.call(['sed', '-i', 's/IPV6=.*/IPV6=no/g',
+                                 '/etc/default/ufw'])
+    if exit_code == 0:
+        hookenv.log('IPv6 support in ufw disabled', level='INFO')
+    else:
+        hookenv.log("Couldn't disable IPv6 support in ufw", level="ERROR")
+        raise UFWError("Couldn't disable IPv6 support in ufw")
+
+
+def enable(soft_fail=False):
+    """
+    Enable ufw
+
+    :param soft_fail: If set to True silently disables IPv6 support in ufw,
+                      otherwise a UFWIPv6Error exception is raised when IP6
+                      support is broken.
+    :returns: True if ufw is successfully enabled
+    """
+    if is_enabled():
+        return True
+
+    if not is_ipv6_ok(soft_fail):
+        disable_ipv6()
+
+    output = subprocess.check_output(['ufw', 'enable'],
+                                     universal_newlines=True,
+                                     env={'LANG': 'en_US',
+                                          'PATH': os.environ['PATH']})
+
+    m = re.findall('^Firewall is active and enabled on system startup\n',
+                   output, re.M)
+    hookenv.log(output, level='DEBUG')
+
+    if len(m) == 0:
+        hookenv.log("ufw couldn't be enabled", level='WARN')
+        return False
+    else:
+        hookenv.log("ufw enabled", level='INFO')
+        return True
+
+
+def disable():
+    """
+    Disable ufw
+
+    :returns: True if ufw is successfully disabled
+    """
+    if not is_enabled():
+        return True
+
+    output = subprocess.check_output(['ufw', 'disable'],
+                                     universal_newlines=True,
+                                     env={'LANG': 'en_US',
+                                          'PATH': os.environ['PATH']})
+
+    m = re.findall(r'^Firewall stopped and disabled on system startup\n',
+                   output, re.M)
+    hookenv.log(output, level='DEBUG')
+
+    if len(m) == 0:
+        hookenv.log("ufw couldn't be disabled", level='WARN')
+        return False
+    else:
+        hookenv.log("ufw disabled", level='INFO')
+        return True
+
+
+def modify_access(src, dst='any', port=None, proto=None, action='allow'):
+    """
+    Grant access to an address or subnet
+
+    :param src: address (e.g. 192.168.1.234) or subnet
+                (e.g. 192.168.1.0/24).
+    :param dst: destiny of the connection, if the machine has multiple IPs and
+                connections to only one of those have to accepted this is the
+                field has to be set.
+    :param port: destiny port
+    :param proto: protocol (tcp or udp)
+    :param action: `allow` or `delete`
+    """
+    if not is_enabled():
+        hookenv.log('ufw is disabled, skipping modify_access()', level='WARN')
+        return
+
+    if action == 'delete':
+        cmd = ['ufw', 'delete', 'allow']
+    else:
+        cmd = ['ufw', action]
+
+    if src is not None:
+        cmd += ['from', src]
+
+    if dst is not None:
+        cmd += ['to', dst]
+
+    if port is not None:
+        cmd += ['port', str(port)]
+
+    if proto is not None:
+        cmd += ['proto', proto]
+
+    hookenv.log('ufw {}: {}'.format(action, ' '.join(cmd)), level='DEBUG')
+    p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+    (stdout, stderr) = p.communicate()
+
+    hookenv.log(stdout, level='INFO')
+
+    if p.returncode != 0:
+        hookenv.log(stderr, level='ERROR')
+        hookenv.log('Error running: {}, exit code: {}'.format(' '.join(cmd),
+                                                              p.returncode),
+                    level='ERROR')
+
+
+def grant_access(src, dst='any', port=None, proto=None):
+    """
+    Grant access to an address or subnet
+
+    :param src: address (e.g. 192.168.1.234) or subnet
+                (e.g. 192.168.1.0/24).
+    :param dst: destiny of the connection, if the machine has multiple IPs and
+                connections to only one of those have to accepted this is the
+                field has to be set.
+    :param port: destiny port
+    :param proto: protocol (tcp or udp)
+    """
+    return modify_access(src, dst=dst, port=port, proto=proto, action='allow')
+
+
+def revoke_access(src, dst='any', port=None, proto=None):
+    """
+    Revoke access to an address or subnet
+
+    :param src: address (e.g. 192.168.1.234) or subnet
+                (e.g. 192.168.1.0/24).
+    :param dst: destiny of the connection, if the machine has multiple IPs and
+                connections to only one of those have to accepted this is the
+                field has to be set.
+    :param port: destiny port
+    :param proto: protocol (tcp or udp)
+    """
+    return modify_access(src, dst=dst, port=port, proto=proto, action='delete')
+
+
+def service(name, action):
+    """
+    Open/close access to a service
+
+    :param name: could be a service name defined in `/etc/services` or a port
+                 number.
+    :param action: `open` or `close`
+    """
+    if action == 'open':
+        subprocess.check_output(['ufw', 'allow', str(name)],
+                                universal_newlines=True)
+    elif action == 'close':
+        subprocess.check_output(['ufw', 'delete', 'allow', str(name)],
+                                universal_newlines=True)
+    else:
+        raise UFWError(("'{}' not supported, use 'allow' "
+                        "or 'delete'").format(action))
 
=== added directory 'hooks/charmhelpers/contrib/openstack'
=== added file 'hooks/charmhelpers/contrib/openstack/__init__.py'
--- hooks/charmhelpers/contrib/openstack/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,15 @@
+# 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/>.
 
=== added file 'hooks/charmhelpers/contrib/openstack/alternatives.py'
--- hooks/charmhelpers/contrib/openstack/alternatives.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/alternatives.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,33 @@
+# 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/>.
+
+''' Helper for managing alternatives for file conflict resolution '''
+
+import subprocess
+import shutil
+import os
+
+
+def install_alternative(name, target, source, priority=50):
+    ''' Install alternative configuration '''
+    if (os.path.exists(target) and not os.path.islink(target)):
+        # Move existing file/directory away before installing
+        shutil.move(target, '{}.bak'.format(target))
+    cmd = [
+        'update-alternatives', '--force', '--install',
+        target, name, source, str(priority)
+    ]
+    subprocess.check_call(cmd)
 
=== added directory 'hooks/charmhelpers/contrib/openstack/amulet'
=== added file 'hooks/charmhelpers/contrib/openstack/amulet/__init__.py'
--- hooks/charmhelpers/contrib/openstack/amulet/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/amulet/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,15 @@
+# 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/>.
 
=== added file 'hooks/charmhelpers/contrib/openstack/amulet/deployment.py'
--- hooks/charmhelpers/contrib/openstack/amulet/deployment.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/amulet/deployment.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,108 @@
+# 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 six
+from charmhelpers.contrib.amulet.deployment import (
+    AmuletDeployment
+)
+
+
+class OpenStackAmuletDeployment(AmuletDeployment):
+    """OpenStack amulet deployment.
+
+       This class inherits from AmuletDeployment and has additional support
+       that is specifically for use by OpenStack charms.
+       """
+
+    def __init__(self, series=None, openstack=None, source=None, stable=True):
+        """Initialize the deployment environment."""
+        super(OpenStackAmuletDeployment, self).__init__(series)
+        self.openstack = openstack
+        self.source = source
+        self.stable = stable
+        # Note(coreycb): this needs to be changed when new next branches come
+        # out.
+        self.current_next = "trusty"
+
+    def _determine_branch_locations(self, other_services):
+        """Determine the branch locations for the other services.
+
+           Determine if the local branch being tested is derived from its
+           stable or next (dev) branch, and based on this, use the corresonding
+           stable or next branches for the other_services."""
+        base_charms = ['mysql', 'mongodb', 'rabbitmq-server']
+
+        if self.stable:
+            for svc in other_services:
+                temp = 'lp:charms/{}'
+                svc['location'] = temp.format(svc['name'])
+        else:
+            for svc in other_services:
+                if svc['name'] in base_charms:
+                    temp = 'lp:charms/{}'
+                    svc['location'] = temp.format(svc['name'])
+                else:
+                    temp = 'lp:~openstack-charmers/charms/{}/{}/next'
+                    svc['location'] = temp.format(self.current_next,
+                                                  svc['name'])
+        return other_services
+
+    def _add_services(self, this_service, other_services):
+        """Add services to the deployment and set openstack-origin/source."""
+        other_services = self._determine_branch_locations(other_services)
+
+        super(OpenStackAmuletDeployment, self)._add_services(this_service,
+                                                             other_services)
+
+        services = other_services
+        services.append(this_service)
+        use_source = ['mysql', 'mongodb', 'rabbitmq-server', 'ceph',
+                      'ceph-osd', 'ceph-radosgw']
+
+        if self.openstack:
+            for svc in services:
+                if svc['name'] not in use_source:
+                    config = {'openstack-origin': self.openstack}
+                    self.d.configure(svc['name'], config)
+
+        if self.source:
+            for svc in services:
+                if svc['name'] in use_source:
+                    config = {'source': self.source}
+                    self.d.configure(svc['name'], config)
+
+    def _configure_services(self, configs):
+        """Configure all of the services."""
+        for service, config in six.iteritems(configs):
+            self.d.configure(service, config)
+
+    def _get_openstack_release(self):
+        """Get openstack release.
+
+           Return an integer representing the enum value of the openstack
+           release.
+           """
+        (self.precise_essex, self.precise_folsom, self.precise_grizzly,
+         self.precise_havana, self.precise_icehouse,
+         self.trusty_icehouse) = range(6)
+        releases = {
+            ('precise', None): self.precise_essex,
+            ('precise', 'cloud:precise-folsom'): self.precise_folsom,
+            ('precise', 'cloud:precise-grizzly'): self.precise_grizzly,
+            ('precise', 'cloud:precise-havana'): self.precise_havana,
+            ('precise', 'cloud:precise-icehouse'): self.precise_icehouse,
+            ('trusty', None): self.trusty_icehouse}
+        return releases[(self.series, self.openstack)]
 
=== added file 'hooks/charmhelpers/contrib/openstack/amulet/utils.py'
--- hooks/charmhelpers/contrib/openstack/amulet/utils.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/amulet/utils.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,294 @@
+# 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 logging
+import os
+import time
+import urllib
+
+import glanceclient.v1.client as glance_client
+import keystoneclient.v2_0 as keystone_client
+import novaclient.v1_1.client as nova_client
+
+import six
+
+from charmhelpers.contrib.amulet.utils import (
+    AmuletUtils
+)
+
+DEBUG = logging.DEBUG
+ERROR = logging.ERROR
+
+
+class OpenStackAmuletUtils(AmuletUtils):
+    """OpenStack amulet utilities.
+
+       This class inherits from AmuletUtils and has additional support
+       that is specifically for use by OpenStack charms.
+       """
+
+    def __init__(self, log_level=ERROR):
+        """Initialize the deployment environment."""
+        super(OpenStackAmuletUtils, self).__init__(log_level)
+
+    def validate_endpoint_data(self, endpoints, admin_port, internal_port,
+                               public_port, expected):
+        """Validate endpoint data.
+
+           Validate actual endpoint data vs expected endpoint data. The ports
+           are used to find the matching endpoint.
+           """
+        found = False
+        for ep in endpoints:
+            self.log.debug('endpoint: {}'.format(repr(ep)))
+            if (admin_port in ep.adminurl and
+                    internal_port in ep.internalurl and
+                    public_port in ep.publicurl):
+                found = True
+                actual = {'id': ep.id,
+                          'region': ep.region,
+                          'adminurl': ep.adminurl,
+                          'internalurl': ep.internalurl,
+                          'publicurl': ep.publicurl,
+                          'service_id': ep.service_id}
+                ret = self._validate_dict_data(expected, actual)
+                if ret:
+                    return 'unexpected endpoint data - {}'.format(ret)
+
+        if not found:
+            return 'endpoint not found'
+
+    def validate_svc_catalog_endpoint_data(self, expected, actual):
+        """Validate service catalog endpoint data.
+
+           Validate a list of actual service catalog endpoints vs a list of
+           expected service catalog endpoints.
+           """
+        self.log.debug('actual: {}'.format(repr(actual)))
+        for k, v in six.iteritems(expected):
+            if k in actual:
+                ret = self._validate_dict_data(expected[k][0], actual[k][0])
+                if ret:
+                    return self.endpoint_error(k, ret)
+            else:
+                return "endpoint {} does not exist".format(k)
+        return ret
+
+    def validate_tenant_data(self, expected, actual):
+        """Validate tenant data.
+
+           Validate a list of actual tenant data vs list of expected tenant
+           data.
+           """
+        self.log.debug('actual: {}'.format(repr(actual)))
+        for e in expected:
+            found = False
+            for act in actual:
+                a = {'enabled': act.enabled, 'description': act.description,
+                     'name': act.name, 'id': act.id}
+                if e['name'] == a['name']:
+                    found = True
+                    ret = self._validate_dict_data(e, a)
+                    if ret:
+                        return "unexpected tenant data - {}".format(ret)
+            if not found:
+                return "tenant {} does not exist".format(e['name'])
+        return ret
+
+    def validate_role_data(self, expected, actual):
+        """Validate role data.
+
+           Validate a list of actual role data vs a list of expected role
+           data.
+           """
+        self.log.debug('actual: {}'.format(repr(actual)))
+        for e in expected:
+            found = False
+            for act in actual:
+                a = {'name': act.name, 'id': act.id}
+                if e['name'] == a['name']:
+                    found = True
+                    ret = self._validate_dict_data(e, a)
+                    if ret:
+                        return "unexpected role data - {}".format(ret)
+            if not found:
+                return "role {} does not exist".format(e['name'])
+        return ret
+
+    def validate_user_data(self, expected, actual):
+        """Validate user data.
+
+           Validate a list of actual user data vs a list of expected user
+           data.
+           """
+        self.log.debug('actual: {}'.format(repr(actual)))
+        for e in expected:
+            found = False
+            for act in actual:
+                a = {'enabled': act.enabled, 'name': act.name,
+                     'email': act.email, 'tenantId': act.tenantId,
+                     'id': act.id}
+                if e['name'] == a['name']:
+                    found = True
+                    ret = self._validate_dict_data(e, a)
+                    if ret:
+                        return "unexpected user data - {}".format(ret)
+            if not found:
+                return "user {} does not exist".format(e['name'])
+        return ret
+
+    def validate_flavor_data(self, expected, actual):
+        """Validate flavor data.
+
+           Validate a list of actual flavors vs a list of expected flavors.
+           """
+        self.log.debug('actual: {}'.format(repr(actual)))
+        act = [a.name for a in actual]
+        return self._validate_list_data(expected, act)
+
+    def tenant_exists(self, keystone, tenant):
+        """Return True if tenant exists."""
+        return tenant in [t.name for t in keystone.tenants.list()]
+
+    def authenticate_keystone_admin(self, keystone_sentry, user, password,
+                                    tenant):
+        """Authenticates admin user with the keystone admin endpoint."""
+        unit = keystone_sentry
+        service_ip = unit.relation('shared-db',
+                                   'mysql:shared-db')['private-address']
+        ep = "http://{}:35357/v2.0".format(service_ip.strip().decode('utf-8'))
+        return keystone_client.Client(username=user, password=password,
+                                      tenant_name=tenant, auth_url=ep)
+
+    def authenticate_keystone_user(self, keystone, user, password, tenant):
+        """Authenticates a regular user with the keystone public endpoint."""
+        ep = keystone.service_catalog.url_for(service_type='identity',
+                                              endpoint_type='publicURL')
+        return keystone_client.Client(username=user, password=password,
+                                      tenant_name=tenant, auth_url=ep)
+
+    def authenticate_glance_admin(self, keystone):
+        """Authenticates admin user with glance."""
+        ep = keystone.service_catalog.url_for(service_type='image',
+                                              endpoint_type='adminURL')
+        return glance_client.Client(ep, token=keystone.auth_token)
+
+    def authenticate_nova_user(self, keystone, user, password, tenant):
+        """Authenticates a regular user with nova-api."""
+        ep = keystone.service_catalog.url_for(service_type='identity',
+                                              endpoint_type='publicURL')
+        return nova_client.Client(username=user, api_key=password,
+                                  project_id=tenant, auth_url=ep)
+
+    def create_cirros_image(self, glance, image_name):
+        """Download the latest cirros image and upload it to glance."""
+        http_proxy = os.getenv('AMULET_HTTP_PROXY')
+        self.log.debug('AMULET_HTTP_PROXY: {}'.format(http_proxy))
+        if http_proxy:
+            proxies = {'http': http_proxy}
+            opener = urllib.FancyURLopener(proxies)
+        else:
+            opener = urllib.FancyURLopener()
+
+        f = opener.open("http://download.cirros-cloud.net/version/released")
+        version = f.read().strip()
+        cirros_img = "cirros-{}-x86_64-disk.img".format(version)
+        local_path = os.path.join('tests', cirros_img)
+
+        if not os.path.exists(local_path):
+            cirros_url = "http://{}/{}/{}".format("download.cirros-cloud.net",
+                                                  version, cirros_img)
+            opener.retrieve(cirros_url, local_path)
+        f.close()
+
+        with open(local_path) as f:
+            image = glance.images.create(name=image_name, is_public=True,
+                                         disk_format='qcow2',
+                                         container_format='bare', data=f)
+        count = 1
+        status = image.status
+        while status != 'active' and count < 10:
+            time.sleep(3)
+            image = glance.images.get(image.id)
+            status = image.status
+            self.log.debug('image status: {}'.format(status))
+            count += 1
+
+        if status != 'active':
+            self.log.error('image creation timed out')
+            return None
+
+        return image
+
+    def delete_image(self, glance, image):
+        """Delete the specified image."""
+        num_before = len(list(glance.images.list()))
+        glance.images.delete(image)
+
+        count = 1
+        num_after = len(list(glance.images.list()))
+        while num_after != (num_before - 1) and count < 10:
+            time.sleep(3)
+            num_after = len(list(glance.images.list()))
+            self.log.debug('number of images: {}'.format(num_after))
+            count += 1
+
+        if num_after != (num_before - 1):
+            self.log.error('image deletion timed out')
+            return False
+
+        return True
+
+    def create_instance(self, nova, image_name, instance_name, flavor):
+        """Create the specified instance."""
+        image = nova.images.find(name=image_name)
+        flavor = nova.flavors.find(name=flavor)
+        instance = nova.servers.create(name=instance_name, image=image,
+                                       flavor=flavor)
+
+        count = 1
+        status = instance.status
+        while status != 'ACTIVE' and count < 60:
+            time.sleep(3)
+            instance = nova.servers.get(instance.id)
+            status = instance.status
+            self.log.debug('instance status: {}'.format(status))
+            count += 1
+
+        if status != 'ACTIVE':
+            self.log.error('instance creation timed out')
+            return None
+
+        return instance
+
+    def delete_instance(self, nova, instance):
+        """Delete the specified instance."""
+        num_before = len(list(nova.servers.list()))
+        nova.servers.delete(instance)
+
+        count = 1
+        num_after = len(list(nova.servers.list()))
+        while num_after != (num_before - 1) and count < 10:
+            time.sleep(3)
+            num_after = len(list(nova.servers.list()))
+            self.log.debug('number of instances: {}'.format(num_after))
+            count += 1
+
+        if num_after != (num_before - 1):
+            self.log.error('instance deletion timed out')
+            return False
+
+        return True
 
=== added file 'hooks/charmhelpers/contrib/openstack/context.py'
--- hooks/charmhelpers/contrib/openstack/context.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/context.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,1054 @@
+# 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 json
+import os
+import time
+from base64 import b64decode
+from subprocess import check_call
+
+import six
+
+from charmhelpers.fetch import (
+    apt_install,
+    filter_installed_packages,
+)
+from charmhelpers.core.hookenv import (
+    config,
+    is_relation_made,
+    local_unit,
+    log,
+    relation_get,
+    relation_ids,
+    related_units,
+    relation_set,
+    unit_get,
+    unit_private_ip,
+    charm_name,
+    DEBUG,
+    INFO,
+    WARNING,
+    ERROR,
+)
+
+from charmhelpers.core.sysctl import create as sysctl_create
+
+from charmhelpers.core.host import (
+    mkdir,
+    write_file,
+)
+from charmhelpers.contrib.hahelpers.cluster import (
+    determine_apache_port,
+    determine_api_port,
+    https,
+    is_clustered,
+)
+from charmhelpers.contrib.hahelpers.apache import (
+    get_cert,
+    get_ca_cert,
+    install_ca_cert,
+)
+from charmhelpers.contrib.openstack.neutron import (
+    neutron_plugin_attribute,
+)
+from charmhelpers.contrib.network.ip import (
+    get_address_in_network,
+    get_ipv6_addr,
+    get_netmask_for_address,
+    format_ipv6_addr,
+    is_address_in_network,
+)
+from charmhelpers.contrib.openstack.utils import get_host_ip
+
+CA_CERT_PATH = '/usr/local/share/ca-certificates/keystone_juju_ca_cert.crt'
+ADDRESS_TYPES = ['admin', 'internal', 'public']
+
+
+class OSContextError(Exception):
+    pass
+
+
+def ensure_packages(packages):
+    """Install but do not upgrade required plugin packages."""
+    required = filter_installed_packages(packages)
+    if required:
+        apt_install(required, fatal=True)
+
+
+def context_complete(ctxt):
+    _missing = []
+    for k, v in six.iteritems(ctxt):
+        if v is None or v == '':
+            _missing.append(k)
+
+    if _missing:
+        log('Missing required data: %s' % ' '.join(_missing), level=INFO)
+        return False
+
+    return True
+
+
+def config_flags_parser(config_flags):
+    """Parses config flags string into dict.
+
+    The provided config_flags string may be a list of comma-separated values
+    which themselves may be comma-separated list of values.
+    """
+    if config_flags.find('==') >= 0:
+        log("config_flags is not in expected format (key=value)", level=ERROR)
+        raise OSContextError
+
+    # strip the following from each value.
+    post_strippers = ' ,'
+    # we strip any leading/trailing '=' or ' ' from the string then
+    # split on '='.
+    split = config_flags.strip(' =').split('=')
+    limit = len(split)
+    flags = {}
+    for i in range(0, limit - 1):
+        current = split[i]
+        next = split[i + 1]
+        vindex = next.rfind(',')
+        if (i == limit - 2) or (vindex < 0):
+            value = next
+        else:
+            value = next[:vindex]
+
+        if i == 0:
+            key = current
+        else:
+            # if this not the first entry, expect an embedded key.
+            index = current.rfind(',')
+            if index < 0:
+                log("Invalid config value(s) at index %s" % (i), level=ERROR)
+                raise OSContextError
+            key = current[index + 1:]
+
+        # Add to collection.
+        flags[key.strip(post_strippers)] = value.rstrip(post_strippers)
+
+    return flags
+
+
+class OSContextGenerator(object):
+    """Base class for all context generators."""
+    interfaces = []
+
+    def __call__(self):
+        raise NotImplementedError
+
+
+class SharedDBContext(OSContextGenerator):
+    interfaces = ['shared-db']
+
+    def __init__(self,
+                 database=None, user=None, relation_prefix=None, ssl_dir=None):
+        """Allows inspecting relation for settings prefixed with
+        relation_prefix. This is useful for parsing access for multiple
+        databases returned via the shared-db interface (eg, nova_password,
+        quantum_password)
+        """
+        self.relation_prefix = relation_prefix
+        self.database = database
+        self.user = user
+        self.ssl_dir = ssl_dir
+
+    def __call__(self):
+        self.database = self.database or config('database')
+        self.user = self.user or config('database-user')
+        if None in [self.database, self.user]:
+            log("Could not generate shared_db context. Missing required charm "
+                "config options. (database name and user)", level=ERROR)
+            raise OSContextError
+
+        ctxt = {}
+
+        # NOTE(jamespage) if mysql charm provides a network upon which
+        # access to the database should be made, reconfigure relation
+        # with the service units local address and defer execution
+        access_network = relation_get('access-network')
+        if access_network is not None:
+            if self.relation_prefix is not None:
+                hostname_key = "{}_hostname".format(self.relation_prefix)
+            else:
+                hostname_key = "hostname"
+            access_hostname = get_address_in_network(access_network,
+                                                     unit_get('private-address'))
+            set_hostname = relation_get(attribute=hostname_key,
+                                        unit=local_unit())
+            if set_hostname != access_hostname:
+                relation_set(relation_settings={hostname_key: access_hostname})
+                return ctxt  # Defer any further hook execution for now....
+
+        password_setting = 'password'
+        if self.relation_prefix:
+            password_setting = self.relation_prefix + '_password'
+
+        for rid in relation_ids('shared-db'):
+            for unit in related_units(rid):
+                rdata = relation_get(rid=rid, unit=unit)
+                host = rdata.get('db_host')
+                host = format_ipv6_addr(host) or host
+                ctxt = {
+                    'database_host': host,
+                    'database': self.database,
+                    'database_user': self.user,
+                    'database_password': rdata.get(password_setting),
+                    'database_type': 'mysql'
+                }
+                if context_complete(ctxt):
+                    db_ssl(rdata, ctxt, self.ssl_dir)
+                    return ctxt
+        return {}
+
+
+class PostgresqlDBContext(OSContextGenerator):
+    interfaces = ['pgsql-db']
+
+    def __init__(self, database=None):
+        self.database = database
+
+    def __call__(self):
+        self.database = self.database or config('database')
+        if self.database is None:
+            log('Could not generate postgresql_db context. Missing required '
+                'charm config options. (database name)', level=ERROR)
+            raise OSContextError
+
+        ctxt = {}
+        for rid in relation_ids(self.interfaces[0]):
+            for unit in related_units(rid):
+                rel_host = relation_get('host', rid=rid, unit=unit)
+                rel_user = relation_get('user', rid=rid, unit=unit)
+                rel_passwd = relation_get('password', rid=rid, unit=unit)
+                ctxt = {'database_host': rel_host,
+                        'database': self.database,
+                        'database_user': rel_user,
+                        'database_password': rel_passwd,
+                        'database_type': 'postgresql'}
+                if context_complete(ctxt):
+                    return ctxt
+
+        return {}
+
+
+def db_ssl(rdata, ctxt, ssl_dir):
+    if 'ssl_ca' in rdata and ssl_dir:
+        ca_path = os.path.join(ssl_dir, 'db-client.ca')
+        with open(ca_path, 'w') as fh:
+            fh.write(b64decode(rdata['ssl_ca']))
+
+        ctxt['database_ssl_ca'] = ca_path
+    elif 'ssl_ca' in rdata:
+        log("Charm not setup for ssl support but ssl ca found", level=INFO)
+        return ctxt
+
+    if 'ssl_cert' in rdata:
+        cert_path = os.path.join(
+            ssl_dir, 'db-client.cert')
+        if not os.path.exists(cert_path):
+            log("Waiting 1m for ssl client cert validity", level=INFO)
+            time.sleep(60)
+
+        with open(cert_path, 'w') as fh:
+            fh.write(b64decode(rdata['ssl_cert']))
+
+        ctxt['database_ssl_cert'] = cert_path
+        key_path = os.path.join(ssl_dir, 'db-client.key')
+        with open(key_path, 'w') as fh:
+            fh.write(b64decode(rdata['ssl_key']))
+
+        ctxt['database_ssl_key'] = key_path
+
+    return ctxt
+
+
+class IdentityServiceContext(OSContextGenerator):
+    interfaces = ['identity-service']
+
+    def __call__(self):
+        log('Generating template context for identity-service', level=DEBUG)
+        ctxt = {}
+        for rid in relation_ids('identity-service'):
+            for unit in related_units(rid):
+                rdata = relation_get(rid=rid, unit=unit)
+                serv_host = rdata.get('service_host')
+                serv_host = format_ipv6_addr(serv_host) or serv_host
+                auth_host = rdata.get('auth_host')
+                auth_host = format_ipv6_addr(auth_host) or auth_host
+                svc_protocol = rdata.get('service_protocol') or 'http'
+                auth_protocol = rdata.get('auth_protocol') or 'http'
+                ctxt = {'service_port': rdata.get('service_port'),
+                        'service_host': serv_host,
+                        'auth_host': auth_host,
+                        'auth_port': rdata.get('auth_port'),
+                        'admin_tenant_name': rdata.get('service_tenant'),
+                        'admin_user': rdata.get('service_username'),
+                        'admin_password': rdata.get('service_password'),
+                        'service_protocol': svc_protocol,
+                        'auth_protocol': auth_protocol}
+                if context_complete(ctxt):
+                    # NOTE(jamespage) this is required for >= icehouse
+                    # so a missing value just indicates keystone needs
+                    # upgrading
+                    ctxt['admin_tenant_id'] = rdata.get('service_tenant_id')
+                    return ctxt
+
+        return {}
+
+
+class AMQPContext(OSContextGenerator):
+
+    def __init__(self, ssl_dir=None, rel_name='amqp', relation_prefix=None):
+        self.ssl_dir = ssl_dir
+        self.rel_name = rel_name
+        self.relation_prefix = relation_prefix
+        self.interfaces = [rel_name]
+
+    def __call__(self):
+        log('Generating template context for amqp', level=DEBUG)
+        conf = config()
+        if self.relation_prefix:
+            user_setting = '%s-rabbit-user' % (self.relation_prefix)
+            vhost_setting = '%s-rabbit-vhost' % (self.relation_prefix)
+        else:
+            user_setting = 'rabbit-user'
+            vhost_setting = 'rabbit-vhost'
+
+        try:
+            username = conf[user_setting]
+            vhost = conf[vhost_setting]
+        except KeyError as e:
+            log('Could not generate shared_db context. Missing required charm '
+                'config options: %s.' % e, level=ERROR)
+            raise OSContextError
+
+        ctxt = {}
+        for rid in relation_ids(self.rel_name):
+            ha_vip_only = False
+            for unit in related_units(rid):
+                if relation_get('clustered', rid=rid, unit=unit):
+                    ctxt['clustered'] = True
+                    vip = relation_get('vip', rid=rid, unit=unit)
+                    vip = format_ipv6_addr(vip) or vip
+                    ctxt['rabbitmq_host'] = vip
+                else:
+                    host = relation_get('private-address', rid=rid, unit=unit)
+                    host = format_ipv6_addr(host) or host
+                    ctxt['rabbitmq_host'] = host
+
+                ctxt.update({
+                    'rabbitmq_user': username,
+                    'rabbitmq_password': relation_get('password', rid=rid,
+                                                      unit=unit),
+                    'rabbitmq_virtual_host': vhost,
+                })
+
+                ssl_port = relation_get('ssl_port', rid=rid, unit=unit)
+                if ssl_port:
+                    ctxt['rabbit_ssl_port'] = ssl_port
+
+                ssl_ca = relation_get('ssl_ca', rid=rid, unit=unit)
+                if ssl_ca:
+                    ctxt['rabbit_ssl_ca'] = ssl_ca
+
+                if relation_get('ha_queues', rid=rid, unit=unit) is not None:
+                    ctxt['rabbitmq_ha_queues'] = True
+
+                ha_vip_only = relation_get('ha-vip-only',
+                                           rid=rid, unit=unit) is not None
+
+                if context_complete(ctxt):
+                    if 'rabbit_ssl_ca' in ctxt:
+                        if not self.ssl_dir:
+                            log("Charm not setup for ssl support but ssl ca "
+                                "found", level=INFO)
+                            break
+
+                        ca_path = os.path.join(
+                            self.ssl_dir, 'rabbit-client-ca.pem')
+                        with open(ca_path, 'w') as fh:
+                            fh.write(b64decode(ctxt['rabbit_ssl_ca']))
+                            ctxt['rabbit_ssl_ca'] = ca_path
+
+                    # Sufficient information found = break out!
+                    break
+
+            # Used for active/active rabbitmq >= grizzly
+            if (('clustered' not in ctxt or ha_vip_only) and
+                    len(related_units(rid)) > 1):
+                rabbitmq_hosts = []
+                for unit in related_units(rid):
+                    host = relation_get('private-address', rid=rid, unit=unit)
+                    host = format_ipv6_addr(host) or host
+                    rabbitmq_hosts.append(host)
+
+                ctxt['rabbitmq_hosts'] = ','.join(sorted(rabbitmq_hosts))
+
+        if not context_complete(ctxt):
+            return {}
+
+        return ctxt
+
+
+class CephContext(OSContextGenerator):
+    """Generates context for /etc/ceph/ceph.conf templates."""
+    interfaces = ['ceph']
+
+    def __call__(self):
+        if not relation_ids('ceph'):
+            return {}
+
+        log('Generating template context for ceph', level=DEBUG)
+        mon_hosts = []
+        auth = None
+        key = None
+        use_syslog = str(config('use-syslog')).lower()
+        for rid in relation_ids('ceph'):
+            for unit in related_units(rid):
+                auth = relation_get('auth', rid=rid, unit=unit)
+                key = relation_get('key', rid=rid, unit=unit)
+                ceph_pub_addr = relation_get('ceph-public-address', rid=rid,
+                                             unit=unit)
+                unit_priv_addr = relation_get('private-address', rid=rid,
+                                              unit=unit)
+                ceph_addr = ceph_pub_addr or unit_priv_addr
+                ceph_addr = format_ipv6_addr(ceph_addr) or ceph_addr
+                mon_hosts.append(ceph_addr)
+
+        ctxt = {'mon_hosts': ' '.join(sorted(mon_hosts)),
+                'auth': auth,
+                'key': key,
+                'use_syslog': use_syslog}
+
+        if not os.path.isdir('/etc/ceph'):
+            os.mkdir('/etc/ceph')
+
+        if not context_complete(ctxt):
+            return {}
+
+        ensure_packages(['ceph-common'])
+        return ctxt
+
+
+class HAProxyContext(OSContextGenerator):
+    """Provides half a context for the haproxy template, which describes
+    all peers to be included in the cluster.  Each charm needs to include
+    its own context generator that describes the port mapping.
+    """
+    interfaces = ['cluster']
+
+    def __init__(self, singlenode_mode=False):
+        self.singlenode_mode = singlenode_mode
+
+    def __call__(self):
+        if not relation_ids('cluster') and not self.singlenode_mode:
+            return {}
+
+        if config('prefer-ipv6'):
+            addr = get_ipv6_addr(exc_list=[config('vip')])[0]
+        else:
+            addr = get_host_ip(unit_get('private-address'))
+
+        l_unit = local_unit().replace('/', '-')
+        cluster_hosts = {}
+
+        # NOTE(jamespage): build out map of configured network endpoints
+        # and associated backends
+        for addr_type in ADDRESS_TYPES:
+            cfg_opt = 'os-{}-network'.format(addr_type)
+            laddr = get_address_in_network(config(cfg_opt))
+            if laddr:
+                netmask = get_netmask_for_address(laddr)
+                cluster_hosts[laddr] = {'network': "{}/{}".format(laddr,
+                                                                  netmask),
+                                        'backends': {l_unit: laddr}}
+                for rid in relation_ids('cluster'):
+                    for unit in related_units(rid):
+                        _laddr = relation_get('{}-address'.format(addr_type),
+                                              rid=rid, unit=unit)
+                        if _laddr:
+                            _unit = unit.replace('/', '-')
+                            cluster_hosts[laddr]['backends'][_unit] = _laddr
+
+        # NOTE(jamespage) add backend based on private address - this
+        # with either be the only backend or the fallback if no acls
+        # match in the frontend
+        cluster_hosts[addr] = {}
+        netmask = get_netmask_for_address(addr)
+        cluster_hosts[addr] = {'network': "{}/{}".format(addr, netmask),
+                               'backends': {l_unit: addr}}
+        for rid in relation_ids('cluster'):
+            for unit in related_units(rid):
+                _laddr = relation_get('private-address',
+                                      rid=rid, unit=unit)
+                if _laddr:
+                    _unit = unit.replace('/', '-')
+                    cluster_hosts[addr]['backends'][_unit] = _laddr
+
+        ctxt = {
+            'frontends': cluster_hosts,
+            'default_backend': addr
+        }
+
+        if config('haproxy-server-timeout'):
+            ctxt['haproxy_server_timeout'] = config('haproxy-server-timeout')
+
+        if config('haproxy-client-timeout'):
+            ctxt['haproxy_client_timeout'] = config('haproxy-client-timeout')
+
+        if config('prefer-ipv6'):
+            ctxt['ipv6'] = True
+            ctxt['local_host'] = 'ip6-localhost'
+            ctxt['haproxy_host'] = '::'
+            ctxt['stat_port'] = ':::8888'
+        else:
+            ctxt['local_host'] = '127.0.0.1'
+            ctxt['haproxy_host'] = '0.0.0.0'
+            ctxt['stat_port'] = ':8888'
+
+        for frontend in cluster_hosts:
+            if (len(cluster_hosts[frontend]['backends']) > 1 or
+                    self.singlenode_mode):
+                # Enable haproxy when we have enough peers.
+                log('Ensuring haproxy enabled in /etc/default/haproxy.',
+                    level=DEBUG)
+                with open('/etc/default/haproxy', 'w') as out:
+                    out.write('ENABLED=1\n')
+
+                return ctxt
+
+        log('HAProxy context is incomplete, this unit has no peers.',
+            level=INFO)
+        return {}
+
+
+class ImageServiceContext(OSContextGenerator):
+    interfaces = ['image-service']
+
+    def __call__(self):
+        """Obtains the glance API server from the image-service relation.
+        Useful in nova and cinder (currently).
+        """
+        log('Generating template context for image-service.', level=DEBUG)
+        rids = relation_ids('image-service')
+        if not rids:
+            return {}
+
+        for rid in rids:
+            for unit in related_units(rid):
+                api_server = relation_get('glance-api-server',
+                                          rid=rid, unit=unit)
+                if api_server:
+                    return {'glance_api_servers': api_server}
+
+        log("ImageService context is incomplete. Missing required relation "
+            "data.", level=INFO)
+        return {}
+
+
+class ApacheSSLContext(OSContextGenerator):
+    """Generates a context for an apache vhost configuration that configures
+    HTTPS reverse proxying for one or many endpoints.  Generated context
+    looks something like::
+
+        {
+            'namespace': 'cinder',
+            'private_address': 'iscsi.mycinderhost.com',
+            'endpoints': [(8776, 8766), (8777, 8767)]
+        }
+
+    The endpoints list consists of a tuples mapping external ports
+    to internal ports.
+    """
+    interfaces = ['https']
+
+    # charms should inherit this context and set external ports
+    # and service namespace accordingly.
+    external_ports = []
+    service_namespace = None
+
+    def enable_modules(self):
+        cmd = ['a2enmod', 'ssl', 'proxy', 'proxy_http']
+        check_call(cmd)
+
+    def configure_cert(self, cn=None):
+        ssl_dir = os.path.join('/etc/apache2/ssl/', self.service_namespace)
+        mkdir(path=ssl_dir)
+        cert, key = get_cert(cn)
+        if cn:
+            cert_filename = 'cert_{}'.format(cn)
+            key_filename = 'key_{}'.format(cn)
+        else:
+            cert_filename = 'cert'
+            key_filename = 'key'
+
+        write_file(path=os.path.join(ssl_dir, cert_filename),
+                   content=b64decode(cert))
+        write_file(path=os.path.join(ssl_dir, key_filename),
+                   content=b64decode(key))
+
+    def configure_ca(self):
+        ca_cert = get_ca_cert()
+        if ca_cert:
+            install_ca_cert(b64decode(ca_cert))
+
+    def canonical_names(self):
+        """Figure out which canonical names clients will access this service.
+        """
+        cns = []
+        for r_id in relation_ids('identity-service'):
+            for unit in related_units(r_id):
+                rdata = relation_get(rid=r_id, unit=unit)
+                for k in rdata:
+                    if k.startswith('ssl_key_'):
+                        cns.append(k.lstrip('ssl_key_'))
+
+        return sorted(list(set(cns)))
+
+    def get_network_addresses(self):
+        """For each network configured, return corresponding address and vip
+           (if available).
+
+        Returns a list of tuples of the form:
+
+            [(address_in_net_a, vip_in_net_a),
+             (address_in_net_b, vip_in_net_b),
+             ...]
+
+            or, if no vip(s) available:
+
+            [(address_in_net_a, address_in_net_a),
+             (address_in_net_b, address_in_net_b),
+             ...]
+        """
+        addresses = []
+        if config('vip'):
+            vips = config('vip').split()
+        else:
+            vips = []
+
+        for net_type in ['os-internal-network', 'os-admin-network',
+                         'os-public-network']:
+            addr = get_address_in_network(config(net_type),
+                                          unit_get('private-address'))
+            if len(vips) > 1 and is_clustered():
+                if not config(net_type):
+                    log("Multiple networks configured but net_type "
+                        "is None (%s)." % net_type, level=WARNING)
+                    continue
+
+                for vip in vips:
+                    if is_address_in_network(config(net_type), vip):
+                        addresses.append((addr, vip))
+                        break
+
+            elif is_clustered() and config('vip'):
+                addresses.append((addr, config('vip')))
+            else:
+                addresses.append((addr, addr))
+
+        return sorted(addresses)
+
+    def __call__(self):
+        if isinstance(self.external_ports, six.string_types):
+            self.external_ports = [self.external_ports]
+
+        if not self.external_ports or not https():
+            return {}
+
+        self.configure_ca()
+        self.enable_modules()
+
+        ctxt = {'namespace': self.service_namespace,
+                'endpoints': [],
+                'ext_ports': []}
+
+        for cn in self.canonical_names():
+            self.configure_cert(cn)
+
+        addresses = self.get_network_addresses()
+        for address, endpoint in sorted(set(addresses)):
+            for api_port in self.external_ports:
+                ext_port = determine_apache_port(api_port,
+                                                 singlenode_mode=True)
+                int_port = determine_api_port(api_port, singlenode_mode=True)
+                portmap = (address, endpoint, int(ext_port), int(int_port))
+                ctxt['endpoints'].append(portmap)
+                ctxt['ext_ports'].append(int(ext_port))
+
+        ctxt['ext_ports'] = sorted(list(set(ctxt['ext_ports'])))
+        return ctxt
+
+
+class NeutronContext(OSContextGenerator):
+    interfaces = []
+
+    @property
+    def plugin(self):
+        return None
+
+    @property
+    def network_manager(self):
+        return None
+
+    @property
+    def packages(self):
+        return neutron_plugin_attribute(self.plugin, 'packages',
+                                        self.network_manager)
+
+    @property
+    def neutron_security_groups(self):
+        return None
+
+    def _ensure_packages(self):
+        for pkgs in self.packages:
+            ensure_packages(pkgs)
+
+    def _save_flag_file(self):
+        if self.network_manager == 'quantum':
+            _file = '/etc/nova/quantum_plugin.conf'
+        else:
+            _file = '/etc/nova/neutron_plugin.conf'
+
+        with open(_file, 'wb') as out:
+            out.write(self.plugin + '\n')
+
+    def ovs_ctxt(self):
+        driver = neutron_plugin_attribute(self.plugin, 'driver',
+                                          self.network_manager)
+        config = neutron_plugin_attribute(self.plugin, 'config',
+                                          self.network_manager)
+        ovs_ctxt = {'core_plugin': driver,
+                    'neutron_plugin': 'ovs',
+                    'neutron_security_groups': self.neutron_security_groups,
+                    'local_ip': unit_private_ip(),
+                    'config': config}
+
+        return ovs_ctxt
+
+    def nvp_ctxt(self):
+        driver = neutron_plugin_attribute(self.plugin, 'driver',
+                                          self.network_manager)
+        config = neutron_plugin_attribute(self.plugin, 'config',
+                                          self.network_manager)
+        nvp_ctxt = {'core_plugin': driver,
+                    'neutron_plugin': 'nvp',
+                    'neutron_security_groups': self.neutron_security_groups,
+                    'local_ip': unit_private_ip(),
+                    'config': config}
+
+        return nvp_ctxt
+
+    def n1kv_ctxt(self):
+        driver = neutron_plugin_attribute(self.plugin, 'driver',
+                                          self.network_manager)
+        n1kv_config = neutron_plugin_attribute(self.plugin, 'config',
+                                               self.network_manager)
+        n1kv_user_config_flags = config('n1kv-config-flags')
+        restrict_policy_profiles = config('n1kv-restrict-policy-profiles')
+        n1kv_ctxt = {'core_plugin': driver,
+                     'neutron_plugin': 'n1kv',
+                     'neutron_security_groups': self.neutron_security_groups,
+                     'local_ip': unit_private_ip(),
+                     'config': n1kv_config,
+                     'vsm_ip': config('n1kv-vsm-ip'),
+                     'vsm_username': config('n1kv-vsm-username'),
+                     'vsm_password': config('n1kv-vsm-password'),
+                     'restrict_policy_profiles': restrict_policy_profiles}
+
+        if n1kv_user_config_flags:
+            flags = config_flags_parser(n1kv_user_config_flags)
+            n1kv_ctxt['user_config_flags'] = flags
+
+        return n1kv_ctxt
+
+    def calico_ctxt(self):
+        driver = neutron_plugin_attribute(self.plugin, 'driver',
+                                          self.network_manager)
+        config = neutron_plugin_attribute(self.plugin, 'config',
+                                          self.network_manager)
+        calico_ctxt = {'core_plugin': driver,
+                       'neutron_plugin': 'Calico',
+                       'neutron_security_groups': self.neutron_security_groups,
+                       'local_ip': unit_private_ip(),
+                       'config': config}
+
+        return calico_ctxt
+
+    def neutron_ctxt(self):
+        if https():
+            proto = 'https'
+        else:
+            proto = 'http'
+
+        if is_clustered():
+            host = config('vip')
+        else:
+            host = unit_get('private-address')
+
+        ctxt = {'network_manager': self.network_manager,
+                'neutron_url': '%s://%s:%s' % (proto, host, '9696')}
+        return ctxt
+
+    def __call__(self):
+        self._ensure_packages()
+
+        if self.network_manager not in ['quantum', 'neutron']:
+            return {}
+
+        if not self.plugin:
+            return {}
+
+        ctxt = self.neutron_ctxt()
+
+        if self.plugin == 'ovs':
+            ctxt.update(self.ovs_ctxt())
+        elif self.plugin in ['nvp', 'nsx']:
+            ctxt.update(self.nvp_ctxt())
+        elif self.plugin == 'n1kv':
+            ctxt.update(self.n1kv_ctxt())
+        elif self.plugin == 'Calico':
+            ctxt.update(self.calico_ctxt())
+
+        alchemy_flags = config('neutron-alchemy-flags')
+        if alchemy_flags:
+            flags = config_flags_parser(alchemy_flags)
+            ctxt['neutron_alchemy_flags'] = flags
+
+        self._save_flag_file()
+        return ctxt
+
+
+class OSConfigFlagContext(OSContextGenerator):
+    """Provides support for user-defined config flags.
+
+    Users can define a comma-seperated list of key=value pairs
+    in the charm configuration and apply them at any point in
+    any file by using a template flag.
+
+    Sometimes users might want config flags inserted within a
+    specific section so this class allows users to specify the
+    template flag name, allowing for multiple template flags
+    (sections) within the same context.
+
+    NOTE: the value of config-flags may be a comma-separated list of
+          key=value pairs and some Openstack config files support
+          comma-separated lists as values.
+    """
+
+    def __init__(self, charm_flag='config-flags',
+                 template_flag='user_config_flags'):
+        """
+        :param charm_flag: config flags in charm configuration.
+        :param template_flag: insert point for user-defined flags in template
+                              file.
+        """
+        super(OSConfigFlagContext, self).__init__()
+        self._charm_flag = charm_flag
+        self._template_flag = template_flag
+
+    def __call__(self):
+        config_flags = config(self._charm_flag)
+        if not config_flags:
+            return {}
+
+        return {self._template_flag:
+                config_flags_parser(config_flags)}
+
+
+class SubordinateConfigContext(OSContextGenerator):
+
+    """
+    Responsible for inspecting relations to subordinates that
+    may be exporting required config via a json blob.
+
+    The subordinate interface allows subordinates to export their
+    configuration requirements to the principle for multiple config
+    files and multiple serivces.  Ie, a subordinate that has interfaces
+    to both glance and nova may export to following yaml blob as json::
+
+        glance:
+            /etc/glance/glance-api.conf:
+                sections:
+                    DEFAULT:
+                        - [key1, value1]
+            /etc/glance/glance-registry.conf:
+                    MYSECTION:
+                        - [key2, value2]
+        nova:
+            /etc/nova/nova.conf:
+                sections:
+                    DEFAULT:
+                        - [key3, value3]
+
+
+    It is then up to the principle charms to subscribe this context to
+    the service+config file it is interestd in.  Configuration data will
+    be available in the template context, in glance's case, as::
+
+        ctxt = {
+            ... other context ...
+            'subordinate_config': {
+                'DEFAULT': {
+                    'key1': 'value1',
+                },
+                'MYSECTION': {
+                    'key2': 'value2',
+                },
+            }
+        }
+    """
+
+    def __init__(self, service, config_file, interface):
+        """
+        :param service     : Service name key to query in any subordinate
+                             data found
+        :param config_file : Service's config file to query sections
+        :param interface   : Subordinate interface to inspect
+        """
+        self.service = service
+        self.config_file = config_file
+        self.interface = interface
+
+    def __call__(self):
+        ctxt = {'sections': {}}
+        for rid in relation_ids(self.interface):
+            for unit in related_units(rid):
+                sub_config = relation_get('subordinate_configuration',
+                                          rid=rid, unit=unit)
+                if sub_config and sub_config != '':
+                    try:
+                        sub_config = json.loads(sub_config)
+                    except:
+                        log('Could not parse JSON from subordinate_config '
+                            'setting from %s' % rid, level=ERROR)
+                        continue
+
+                    if self.service not in sub_config:
+                        log('Found subordinate_config on %s but it contained'
+                            'nothing for %s service' % (rid, self.service),
+                            level=INFO)
+                        continue
+
+                    sub_config = sub_config[self.service]
+                    if self.config_file not in sub_config:
+                        log('Found subordinate_config on %s but it contained'
+                            'nothing for %s' % (rid, self.config_file),
+                            level=INFO)
+                        continue
+
+                    sub_config = sub_config[self.config_file]
+                    for k, v in six.iteritems(sub_config):
+                        if k == 'sections':
+                            for section, config_dict in six.iteritems(v):
+                                log("adding section '%s'" % (section),
+                                    level=DEBUG)
+                                ctxt[k][section] = config_dict
+                        else:
+                            ctxt[k] = v
+
+        log("%d section(s) found" % (len(ctxt['sections'])), level=DEBUG)
+        return ctxt
+
+
+class LogLevelContext(OSContextGenerator):
+
+    def __call__(self):
+        ctxt = {}
+        ctxt['debug'] = \
+            False if config('debug') is None else config('debug')
+        ctxt['verbose'] = \
+            False if config('verbose') is None else config('verbose')
+
+        return ctxt
+
+
+class SyslogContext(OSContextGenerator):
+
+    def __call__(self):
+        ctxt = {'use_syslog': config('use-syslog')}
+        return ctxt
+
+
+class BindHostContext(OSContextGenerator):
+
+    def __call__(self):
+        if config('prefer-ipv6'):
+            return {'bind_host': '::'}
+        else:
+            return {'bind_host': '0.0.0.0'}
+
+
+class WorkerConfigContext(OSContextGenerator):
+
+    @property
+    def num_cpus(self):
+        try:
+            from psutil import NUM_CPUS
+        except ImportError:
+            apt_install('python-psutil', fatal=True)
+            from psutil import NUM_CPUS
+
+        return NUM_CPUS
+
+    def __call__(self):
+        multiplier = config('worker-multiplier') or 0
+        ctxt = {"workers": self.num_cpus * multiplier}
+        return ctxt
+
+
+class ZeroMQContext(OSContextGenerator):
+    interfaces = ['zeromq-configuration']
+
+    def __call__(self):
+        ctxt = {}
+        if is_relation_made('zeromq-configuration', 'host'):
+            for rid in relation_ids('zeromq-configuration'):
+                    for unit in related_units(rid):
+                        ctxt['zmq_nonce'] = relation_get('nonce', unit, rid)
+                        ctxt['zmq_host'] = relation_get('host', unit, rid)
+
+        return ctxt
+
+
+class NotificationDriverContext(OSContextGenerator):
+
+    def __init__(self, zmq_relation='zeromq-configuration',
+                 amqp_relation='amqp'):
+        """
+        :param zmq_relation: Name of Zeromq relation to check
+        """
+        self.zmq_relation = zmq_relation
+        self.amqp_relation = amqp_relation
+
+    def __call__(self):
+        ctxt = {'notifications': 'False'}
+        if is_relation_made(self.amqp_relation):
+            ctxt['notifications'] = "True"
+
+        return ctxt
+
+
+class SysctlContext(OSContextGenerator):
+    """This context check if the 'sysctl' option exists on configuration
+    then creates a file with the loaded contents"""
+    def __call__(self):
+        sysctl_dict = config('sysctl')
+        if sysctl_dict:
+            sysctl_create(sysctl_dict,
+                          '/etc/sysctl.d/50-{0}.conf'.format(charm_name()))
+        return {'sysctl': sysctl_dict}
 
=== added file 'hooks/charmhelpers/contrib/openstack/ip.py'
--- hooks/charmhelpers/contrib/openstack/ip.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/ip.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,109 @@
+# 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/>.
+
+from charmhelpers.core.hookenv import (
+    config,
+    unit_get,
+)
+from charmhelpers.contrib.network.ip import (
+    get_address_in_network,
+    is_address_in_network,
+    is_ipv6,
+    get_ipv6_addr,
+)
+from charmhelpers.contrib.hahelpers.cluster import is_clustered
+
+PUBLIC = 'public'
+INTERNAL = 'int'
+ADMIN = 'admin'
+
+ADDRESS_MAP = {
+    PUBLIC: {
+        'config': 'os-public-network',
+        'fallback': 'public-address'
+    },
+    INTERNAL: {
+        'config': 'os-internal-network',
+        'fallback': 'private-address'
+    },
+    ADMIN: {
+        'config': 'os-admin-network',
+        'fallback': 'private-address'
+    }
+}
+
+
+def canonical_url(configs, endpoint_type=PUBLIC):
+    """Returns the correct HTTP URL to this host given the state of HTTPS
+    configuration, hacluster and charm configuration.
+
+    :param configs: OSTemplateRenderer config templating object to inspect
+                    for a complete https context.
+    :param endpoint_type: str endpoint type to resolve.
+    :param returns: str base URL for services on the current service unit.
+    """
+    scheme = 'http'
+    if 'https' in configs.complete_contexts():
+        scheme = 'https'
+    address = resolve_address(endpoint_type)
+    if is_ipv6(address):
+        address = "[{}]".format(address)
+    return '%s://%s' % (scheme, address)
+
+
+def resolve_address(endpoint_type=PUBLIC):
+    """Return unit address depending on net config.
+
+    If unit is clustered with vip(s) and has net splits defined, return vip on
+    correct network. If clustered with no nets defined, return primary vip.
+
+    If not clustered, return unit address ensuring address is on configured net
+    split if one is configured.
+
+    :param endpoint_type: Network endpoing type
+    """
+    resolved_address = None
+    vips = config('vip')
+    if vips:
+        vips = vips.split()
+
+    net_type = ADDRESS_MAP[endpoint_type]['config']
+    net_addr = config(net_type)
+    net_fallback = ADDRESS_MAP[endpoint_type]['fallback']
+    clustered = is_clustered()
+    if clustered:
+        if not net_addr:
+            # If no net-splits defined, we expect a single vip
+            resolved_address = vips[0]
+        else:
+            for vip in vips:
+                if is_address_in_network(net_addr, vip):
+                    resolved_address = vip
+                    break
+    else:
+        if config('prefer-ipv6'):
+            fallback_addr = get_ipv6_addr(exc_list=vips)[0]
+        else:
+            fallback_addr = unit_get(net_fallback)
+
+        resolved_address = get_address_in_network(net_addr, fallback_addr)
+
+    if resolved_address is None:
+        raise ValueError("Unable to resolve a suitable IP address based on "
+                         "charm state and configuration. (net_type=%s, "
+                         "clustered=%s)" % (net_type, clustered))
+
+    return resolved_address
 
=== added file 'hooks/charmhelpers/contrib/openstack/neutron.py'
--- hooks/charmhelpers/contrib/openstack/neutron.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/neutron.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,239 @@
+# 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/>.
+
+# Various utilies for dealing with Neutron and the renaming from Quantum.
+
+from subprocess import check_output
+
+from charmhelpers.core.hookenv import (
+    config,
+    log,
+    ERROR,
+)
+
+from charmhelpers.contrib.openstack.utils import os_release
+
+
+def headers_package():
+    """Ensures correct linux-headers for running kernel are installed,
+    for building DKMS package"""
+    kver = check_output(['uname', '-r']).decode('UTF-8').strip()
+    return 'linux-headers-%s' % kver
+
+QUANTUM_CONF_DIR = '/etc/quantum'
+
+
+def kernel_version():
+    """ Retrieve the current major kernel version as a tuple e.g. (3, 13) """
+    kver = check_output(['uname', '-r']).decode('UTF-8').strip()
+    kver = kver.split('.')
+    return (int(kver[0]), int(kver[1]))
+
+
+def determine_dkms_package():
+    """ Determine which DKMS package should be used based on kernel version """
+    # NOTE: 3.13 kernels have support for GRE and VXLAN native
+    if kernel_version() >= (3, 13):
+        return []
+    else:
+        return ['openvswitch-datapath-dkms']
+
+
+# legacy
+
+
+def quantum_plugins():
+    from charmhelpers.contrib.openstack import context
+    return {
+        'ovs': {
+            'config': '/etc/quantum/plugins/openvswitch/'
+                      'ovs_quantum_plugin.ini',
+            'driver': 'quantum.plugins.openvswitch.ovs_quantum_plugin.'
+                      'OVSQuantumPluginV2',
+            'contexts': [
+                context.SharedDBContext(user=config('neutron-database-user'),
+                                        database=config('neutron-database'),
+                                        relation_prefix='neutron',
+                                        ssl_dir=QUANTUM_CONF_DIR)],
+            'services': ['quantum-plugin-openvswitch-agent'],
+            'packages': [[headers_package()] + determine_dkms_package(),
+                         ['quantum-plugin-openvswitch-agent']],
+            'server_packages': ['quantum-server',
+                                'quantum-plugin-openvswitch'],
+            'server_services': ['quantum-server']
+        },
+        'nvp': {
+            'config': '/etc/quantum/plugins/nicira/nvp.ini',
+            'driver': 'quantum.plugins.nicira.nicira_nvp_plugin.'
+                      'QuantumPlugin.NvpPluginV2',
+            'contexts': [
+                context.SharedDBContext(user=config('neutron-database-user'),
+                                        database=config('neutron-database'),
+                                        relation_prefix='neutron',
+                                        ssl_dir=QUANTUM_CONF_DIR)],
+            'services': [],
+            'packages': [],
+            'server_packages': ['quantum-server',
+                                'quantum-plugin-nicira'],
+            'server_services': ['quantum-server']
+        }
+    }
+
+NEUTRON_CONF_DIR = '/etc/neutron'
+
+
+def neutron_plugins():
+    from charmhelpers.contrib.openstack import context
+    release = os_release('nova-common')
+    plugins = {
+        'ovs': {
+            'config': '/etc/neutron/plugins/openvswitch/'
+                      'ovs_neutron_plugin.ini',
+            'driver': 'neutron.plugins.openvswitch.ovs_neutron_plugin.'
+                      'OVSNeutronPluginV2',
+            'contexts': [
+                context.SharedDBContext(user=config('neutron-database-user'),
+                                        database=config('neutron-database'),
+                                        relation_prefix='neutron',
+                                        ssl_dir=NEUTRON_CONF_DIR)],
+            'services': ['neutron-plugin-openvswitch-agent'],
+            'packages': [[headers_package()] + determine_dkms_package(),
+                         ['neutron-plugin-openvswitch-agent']],
+            'server_packages': ['neutron-server',
+                                'neutron-plugin-openvswitch'],
+            'server_services': ['neutron-server']
+        },
+        'nvp': {
+            'config': '/etc/neutron/plugins/nicira/nvp.ini',
+            'driver': 'neutron.plugins.nicira.nicira_nvp_plugin.'
+                      'NeutronPlugin.NvpPluginV2',
+            'contexts': [
+                context.SharedDBContext(user=config('neutron-database-user'),
+                                        database=config('neutron-database'),
+                                        relation_prefix='neutron',
+                                        ssl_dir=NEUTRON_CONF_DIR)],
+            'services': [],
+            'packages': [],
+            'server_packages': ['neutron-server',
+                                'neutron-plugin-nicira'],
+            'server_services': ['neutron-server']
+        },
+        'nsx': {
+            'config': '/etc/neutron/plugins/vmware/nsx.ini',
+            'driver': 'vmware',
+            'contexts': [
+                context.SharedDBContext(user=config('neutron-database-user'),
+                                        database=config('neutron-database'),
+                                        relation_prefix='neutron',
+                                        ssl_dir=NEUTRON_CONF_DIR)],
+            'services': [],
+            'packages': [],
+            'server_packages': ['neutron-server',
+                                'neutron-plugin-vmware'],
+            'server_services': ['neutron-server']
+        },
+        'n1kv': {
+            'config': '/etc/neutron/plugins/cisco/cisco_plugins.ini',
+            'driver': 'neutron.plugins.cisco.network_plugin.PluginV2',
+            'contexts': [
+                context.SharedDBContext(user=config('neutron-database-user'),
+                                        database=config('neutron-database'),
+                                        relation_prefix='neutron',
+                                        ssl_dir=NEUTRON_CONF_DIR)],
+            'services': [],
+            'packages': [[headers_package()] + determine_dkms_package(),
+                         ['neutron-plugin-cisco']],
+            'server_packages': ['neutron-server',
+                                'neutron-plugin-cisco'],
+            'server_services': ['neutron-server']
+        },
+        'Calico': {
+            'config': '/etc/neutron/plugins/ml2/ml2_conf.ini',
+            'driver': 'neutron.plugins.ml2.plugin.Ml2Plugin',
+            'contexts': [
+                context.SharedDBContext(user=config('neutron-database-user'),
+                                        database=config('neutron-database'),
+                                        relation_prefix='neutron',
+                                        ssl_dir=NEUTRON_CONF_DIR)],
+            'services': ['calico-felix',
+                         'bird',
+                         'neutron-dhcp-agent',
+                         'nova-api-metadata'],
+            'packages': [[headers_package()] + determine_dkms_package(),
+                         ['calico-compute',
+                          'bird',
+                          'neutron-dhcp-agent',
+                          'nova-api-metadata']],
+            'server_packages': ['neutron-server', 'calico-control'],
+            'server_services': ['neutron-server']
+        }
+    }
+    if release >= 'icehouse':
+        # NOTE: patch in ml2 plugin for icehouse onwards
+        plugins['ovs']['config'] = '/etc/neutron/plugins/ml2/ml2_conf.ini'
+        plugins['ovs']['driver'] = 'neutron.plugins.ml2.plugin.Ml2Plugin'
+        plugins['ovs']['server_packages'] = ['neutron-server',
+                                             'neutron-plugin-ml2']
+        # NOTE: patch in vmware renames nvp->nsx for icehouse onwards
+        plugins['nvp'] = plugins['nsx']
+    return plugins
+
+
+def neutron_plugin_attribute(plugin, attr, net_manager=None):
+    manager = net_manager or network_manager()
+    if manager == 'quantum':
+        plugins = quantum_plugins()
+    elif manager == 'neutron':
+        plugins = neutron_plugins()
+    else:
+        log("Network manager '%s' does not support plugins." % (manager),
+            level=ERROR)
+        raise Exception
+
+    try:
+        _plugin = plugins[plugin]
+    except KeyError:
+        log('Unrecognised plugin for %s: %s' % (manager, plugin), level=ERROR)
+        raise Exception
+
+    try:
+        return _plugin[attr]
+    except KeyError:
+        return None
+
+
+def network_manager():
+    '''
+    Deals with the renaming of Quantum to Neutron in H and any situations
+    that require compatability (eg, deploying H with network-manager=quantum,
+    upgrading from G).
+    '''
+    release = os_release('nova-common')
+    manager = config('network-manager').lower()
+
+    if manager not in ['quantum', 'neutron']:
+        return manager
+
+    if release in ['essex']:
+        # E does not support neutron
+        log('Neutron networking not supported in Essex.', level=ERROR)
+        raise Exception
+    elif release in ['folsom', 'grizzly']:
+        # neutron is named quantum in F and G
+        return 'quantum'
+    else:
+        # ensure accurate naming for all releases post-H
+        return 'neutron'
 
=== added directory 'hooks/charmhelpers/contrib/openstack/templates'
=== added file 'hooks/charmhelpers/contrib/openstack/templates/__init__.py'
--- hooks/charmhelpers/contrib/openstack/templates/__init__.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/templates/__init__.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,18 @@
+# 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/>.
+
+# dummy __init__.py to fool syncer into thinking this is a syncable python
+# module
 
=== added file 'hooks/charmhelpers/contrib/openstack/templating.py'
--- hooks/charmhelpers/contrib/openstack/templating.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/contrib/openstack/templating.py	2015-06-18 17:19:58 +0000
@@ -0,0 +1,295 @@
+# 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 os
+
+import six
+
+from charmhelpers.fetch import apt_install
+from charmhelpers.core.hookenv import (
+    log,
+    ERROR,
+    INFO
+)
+from charmhelpers.contrib.openstack.utils import OPENSTACK_CODENAMES
+
+try:
+    from jinja2 import FileSystemLoader, ChoiceLoader, Environment, exceptions
+except ImportError:
+    # python-jinja2 may not be installed yet, or we're running unittests.
+    FileSystemLoader = ChoiceLoader = Environment = exceptions = None
+
+
+class OSConfigException(Exception):
+    pass
+
+
+def get_loader(templates_dir, os_release):
+    """
+    Create a jinja2.ChoiceLoader containing template dirs up to
+    and including os_release.  If directory template directory
+    is missing at templates_dir, it will be omitted from the loader.
+    templates_dir is added to the bottom of the search list as a base
+    loading dir.
+
+    A charm may also ship a templates dir with this module
+    and it will be appended to the bottom of the search list, eg::
+
+        hooks/charmhelpers/contrib/openstack/templates
+
+    :param templates_dir (str): Base template directory containing release
+        sub-directories.
+    :param os_release (str): OpenStack release codename to construct template
+        loader.
+    :returns: jinja2.ChoiceLoader constructed with a list of
+        jinja2.FilesystemLoaders, ordered in descending
+        order by OpenStack release.
+    """
+    tmpl_dirs = [(rel, os.path.join(templates_dir, rel))
+                 for rel in six.itervalues(OPENSTACK_CODENAMES)]
+
+    if not os.path.isdir(templates_dir):
+        log('Templates directory not found @ %s.' % templates_dir,
+            level=ERROR)
+        raise OSConfigException
+