Merge lp:~thedac/charms/precise/rabbitmq-server/enable-nrpe-external-master into lp:charms/rabbitmq-server

[David Ames]

Enable nrpe-external-master-relation.
Use charmhelpers (embedded for now)

[Tom Haddon (mthaddon)]

I think we should change the author of the check_rabbitmq.py script, as that email address no longer works (the person in question has left Canonical). Also I wonder if we can change the NAGIOS_PLUGINS='/usr/lib/nagios/plugins' to NAGIOS_PLUGINS='/usr/local/lib/nagios/plugins' - it seems odd to install non-packaged files in /usr/lib. I think we may need to pre-create the directory, though.

review: Needs Fixing

[lp:~thedac/charms/precise/rabbitmq-server/enable-nrpe-external-master]

46. By David Ames on 2013-11-21

Use /usr/local/lib/nagios/plugins for non-packaged checks

[David Ames (thedac)]

Use /usr/local/lib/nagios/plugins for non-packaged checks
Updated charm-helpers

Mojo tested: https://ci.admin.canonical.com/job/mojo-pes-certification/58/console

[Tom Haddon (mthaddon)]

Looks good, approved. Very nice to be able to see it in Mojo as well...

review: Approve

=== added file 'hooks/_pythonpath.py'
--- hooks/_pythonpath.py	1970-01-01 00:00:00 +0000
+++ hooks/_pythonpath.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,14 @@
+import sys
+import os
+import os.path
+
+# Make sure that charmhelpers is importable, or bail out.
+local_copy = os.path.join(
+    os.path.dirname(os.path.dirname(__file__)), "lib")
+if os.path.exists(local_copy) and os.path.isdir(local_copy):
+    sys.path.insert(0, local_copy)
+try:
+    import charmhelpers
+    _ = charmhelpers
+except ImportError:
+    sys.exit("Could not find required 'charmhelpers' library.")
 
=== added symlink 'hooks/nrpe-external-master-relation-changed'
=== target is u'rabbitmq_server_relations.py'
=== modified file 'hooks/rabbit_utils.py'
--- hooks/rabbit_utils.py	2013-05-20 17:00:03 +0000
+++ hooks/rabbit_utils.py	2013-11-21 22:43:22 +0000
@@ -7,7 +7,7 @@
 import lib.utils as utils
 import apt_pkg as apt
 
-PACKAGES = ['pwgen', 'rabbitmq-server']
+PACKAGES = ['pwgen', 'rabbitmq-server', 'python-amqplib']
 
 RABBITMQ_CTL = '/usr/sbin/rabbitmqctl'
 COOKIE_PATH = '/var/lib/rabbitmq/.erlang.cookie'
 
=== modified file 'hooks/rabbitmq_server_relations.py'
--- hooks/rabbitmq_server_relations.py	2013-10-28 14:12:08 +0000
+++ hooks/rabbitmq_server_relations.py	2013-11-21 22:43:22 +0000
@@ -13,10 +13,17 @@
 import lib.ceph_utils as ceph
 import lib.openstack_common as openstack
 
+import _pythonpath
+_ = _pythonpath
+
+from charmhelpers.core.host import rsync
+from charmhelpers.contrib.charmsupport.nrpe import NRPE
+
 
 SERVICE_NAME = os.getenv('JUJU_UNIT_NAME').split('/')[0]
 POOL_NAME = SERVICE_NAME
 RABBIT_DIR = '/var/lib/rabbitmq'
+NAGIOS_PLUGINS='/usr/local/lib/nagios/plugins'
 
 
 def install():
@@ -237,6 +244,35 @@
     utils.juju_log('INFO', 'Finish Ceph Relation Changed')
 
 
+def update_nrpe_checks():
+    if os.path.isdir(NAGIOS_PLUGINS):
+        rsync(os.path.join(os.getenv('CHARM_DIR'), 'scripts', 'check_rabbitmq.py'),
+              os.path.join(NAGIOS_PLUGINS, 'check_rabbitmq.py'))
+    user = 'naigos'
+    vhost = 'nagios'
+    password_file = os.path.join(RABBIT_DIR, '%s.passwd' % user)
+    if os.path.exists(password_file):
+        password = open(password_file).read().strip()
+    else:
+        cmd = ['pwgen', '64', '1']
+        password = subprocess.check_output(cmd).strip()
+        with open(password_file, 'wb') as out:
+            out.write(password)
+
+    rabbit.create_vhost(vhost)
+    rabbit.create_user(user, password)
+    rabbit.grant_permissions(user, vhost)
+
+    nrpe_compat = NRPE()
+    nrpe_compat.add_check(
+        shortname='rabbitmq',
+        description='Check RabbitMQ',
+        check_cmd='{}/check_rabbitmq.py --user {} --password {} --vhost {}'
+                  ''.format(NAGIOS_PLUGINS, user, password, vhost)
+    )
+    nrpe_compat.write()
+
+
 def upgrade_charm():
     pre_install_hooks()
     # Ensure older passwd files in /var/lib/juju are moved to
@@ -281,6 +317,8 @@
     if cluster.eligible_leader('res_rabbitmq_vip'):
         utils.restart('rabbitmq-server')
 
+    update_nrpe_checks()
+
 
 def pre_install_hooks():
     for f in glob.glob('exec.d/*/charm-pre-install'):
@@ -297,7 +335,8 @@
     'ceph-relation-joined': ceph_joined,
     'ceph-relation-changed': ceph_changed,
     'upgrade-charm': upgrade_charm,
-    'config-changed': config_changed
+    'config-changed': config_changed,
+    'nrpe-external-master-relation-changed': update_nrpe_checks
 }
 
 utils.do_hooks(hooks)
 
=== added directory 'lib'
=== added directory 'lib/charmhelpers'
=== added file 'lib/charmhelpers-0.1.2.egg-info'
--- lib/charmhelpers-0.1.2.egg-info	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers-0.1.2.egg-info	2013-11-21 22:43:22 +0000
@@ -0,0 +1,18 @@
+Metadata-Version: 1.0
+Name: charmhelpers
+Version: 0.1.2
+Summary: UNKNOWN
+Home-page: https://code.launchpad.net/charm-helpers
+Author: Ubuntu Developers
+Author-email: [e-mail]
+License: Affero GNU Public License v3
+Description: ============
+        CharmHelpers
+        ============
+        
+        CharmHelpers provides an opinionated set of tools for building Juju
+        charms that work together. In addition to basic tasks like interact-
+        ing with the charm environment and the machine it runs on, it also
+        helps keep you build hooks and establish relations effortlessly.
+        
+Platform: UNKNOWN
 
=== added file 'lib/charmhelpers/__init__.py'
=== added directory 'lib/charmhelpers/cli'
=== added file 'lib/charmhelpers/cli/__init__.py'
--- lib/charmhelpers/cli/__init__.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/cli/__init__.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,147 @@
+import inspect
+import itertools
+import argparse
+import sys
+
+
+class OutputFormatter(object):
+    def __init__(self, outfile=sys.stdout):
+        self.formats = (
+            "raw",
+            "json",
+            "py",
+            "yaml",
+            "csv",
+            "tab",
+        )
+        self.outfile = outfile
+
+    def add_arguments(self, argument_parser):
+        formatgroup = argument_parser.add_mutually_exclusive_group()
+        choices = self.supported_formats
+        formatgroup.add_argument("--format", metavar='FMT',
+                                 help="Select output format for returned data, "
+                                      "where FMT is one of: {}".format(choices),
+                                 choices=choices, default='raw')
+        for fmt in self.formats:
+            fmtfunc = getattr(self, fmt)
+            formatgroup.add_argument("-{}".format(fmt[0]),
+                                     "--{}".format(fmt), action='store_const',
+                                     const=fmt, dest='format',
+                                     help=fmtfunc.__doc__)
+
+    @property
+    def supported_formats(self):
+        return self.formats
+
+    def raw(self, output):
+        """Output data as raw string (default)"""
+        self.outfile.write(str(output))
+
+    def py(self, output):
+        """Output data as a nicely-formatted python data structure"""
+        import pprint
+        pprint.pprint(output, stream=self.outfile)
+
+    def json(self, output):
+        """Output data in JSON format"""
+        import json
+        json.dump(output, self.outfile)
+
+    def yaml(self, output):
+        """Output data in YAML format"""
+        import yaml
+        yaml.safe_dump(output, self.outfile)
+
+    def csv(self, output):
+        """Output data as excel-compatible CSV"""
+        import csv
+        csvwriter = csv.writer(self.outfile)
+        csvwriter.writerows(output)
+
+    def tab(self, output):
+        """Output data in excel-compatible tab-delimited format"""
+        import csv
+        csvwriter = csv.writer(self.outfile, dialect=csv.excel_tab)
+        csvwriter.writerows(output)
+
+    def format_output(self, output, fmt='raw'):
+        fmtfunc = getattr(self, fmt)
+        fmtfunc(output)
+
+
+class CommandLine(object):
+    argument_parser = None
+    subparsers = None
+    formatter = None
+
+    def __init__(self):
+        if not self.argument_parser:
+            self.argument_parser = argparse.ArgumentParser(description='Perform common charm tasks')
+        if not self.formatter:
+            self.formatter = OutputFormatter()
+            self.formatter.add_arguments(self.argument_parser)
+        if not self.subparsers:
+            self.subparsers = self.argument_parser.add_subparsers(help='Commands')
+
+    def subcommand(self, command_name=None):
+        """
+        Decorate a function as a subcommand. Use its arguments as the
+        command-line arguments"""
+        def wrapper(decorated):
+            cmd_name = command_name or decorated.__name__
+            subparser = self.subparsers.add_parser(cmd_name,
+                                                   description=decorated.__doc__)
+            for args, kwargs in describe_arguments(decorated):
+                subparser.add_argument(*args, **kwargs)
+            subparser.set_defaults(func=decorated)
+            return decorated
+        return wrapper
+
+    def subcommand_builder(self, command_name, description=None):
+        """
+        Decorate a function that builds a subcommand. Builders should accept a
+        single argument (the subparser instance) and return the function to be
+        run as the command."""
+        def wrapper(decorated):
+            subparser = self.subparsers.add_parser(command_name)
+            func = decorated(subparser)
+            subparser.set_defaults(func=func)
+            subparser.description = description or func.__doc__
+        return wrapper
+
+    def run(self):
+        "Run cli, processing arguments and executing subcommands."
+        arguments = self.argument_parser.parse_args()
+        argspec = inspect.getargspec(arguments.func)
+        vargs = []
+        kwargs = {}
+        if argspec.varargs:
+            vargs = getattr(arguments, argspec.varargs)
+        for arg in argspec.args:
+            kwargs[arg] = getattr(arguments, arg)
+        self.formatter.format_output(arguments.func(*vargs, **kwargs), arguments.format)
+
+
+cmdline = CommandLine()
+
+
+def describe_arguments(func):
+    """
+    Analyze a function's signature and return a data structure suitable for
+    passing in as arguments to an argparse parser's add_argument() method."""
+
+    argspec = inspect.getargspec(func)
+    # we should probably raise an exception somewhere if func includes **kwargs
+    if argspec.defaults:
+        positional_args = argspec.args[:-len(argspec.defaults)]
+        keyword_names = argspec.args[-len(argspec.defaults):]
+        for arg, default in itertools.izip(keyword_names, argspec.defaults):
+            yield ('--{}'.format(arg),), {'default': default}
+    else:
+        positional_args = argspec.args
+
+    for arg in positional_args:
+        yield (arg,), {}
+    if argspec.varargs:
+        yield (argspec.varargs,), {'nargs': '*'}
 
=== added file 'lib/charmhelpers/cli/commands.py'
--- lib/charmhelpers/cli/commands.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/cli/commands.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,2 @@
+from . import CommandLine
+import host
 
=== added file 'lib/charmhelpers/cli/host.py'
--- lib/charmhelpers/cli/host.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/cli/host.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,15 @@
+from . import cmdline
+from charmhelpers.core import host
+
+
[e-mail]()
+def mounts():
+    "List mounts"
+    return host.mounts()
+
+
[e-mail]_builder('service', description="Control system services")
+def service(subparser):
+    subparser.add_argument("action", help="The action to perform (start, stop, etc...)")
+    subparser.add_argument("service_name", help="Name of the service to control")
+    return host.service
 
=== added directory 'lib/charmhelpers/contrib'
=== added file 'lib/charmhelpers/contrib/__init__.py'
=== added directory 'lib/charmhelpers/contrib/ansible'
=== added file 'lib/charmhelpers/contrib/ansible/__init__.py'
--- lib/charmhelpers/contrib/ansible/__init__.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/contrib/ansible/__init__.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,101 @@
+# 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[1] and standard ansible modules[2].
+
+[1] http://www.ansibleworks.com/docs/playbooks.html
+[2] http://www.ansibleworks.com/docs/modules.html
+"""
+import os
+import subprocess
+
+import charmhelpers.contrib.saltstack
+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):
+    """Installs the ansible package.
+
+    By default it is installed from the PPA [1] linked from
+    the ansible website [2].
+
+    [1] https://launchpad.net/~rquillo/+archive/ansible
+    [2] http://www.ansibleworks.com/docs/gettingstarted.html#ubuntu-and-debian
+
+    If from_ppa is false, you must ensure that the package is available
+    from a configured repository.
+    """
+    if from_ppa:
+        charmhelpers.fetch.add_source('ppa:rquillo/ansible')
+        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):
+    charmhelpers.contrib.saltstack.juju_state_to_yaml(
+        ansible_vars_path, namespace_separator='__')
+    subprocess.check_call(['ansible-playbook', '-c', 'local', playbook])
 
=== added directory 'lib/charmhelpers/contrib/charmhelpers'
=== added file 'lib/charmhelpers/contrib/charmhelpers/__init__.py'
--- lib/charmhelpers/contrib/charmhelpers/__init__.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/contrib/charmhelpers/__init__.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,184 @@
+# 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)
+
+"""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
+]
+
+import operator
+from shelltoolbox import (
+    command,
+)
+import tempfile
+import time
+import urllib2
+import yaml
+
+SLEEP_AMOUNT = 0.1
+# We create a juju_status Command here because it makes testing much,
+# much easier.
+juju_status = lambda: command('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()
+    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 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 = urllib2.urlopen(url)
+        except (urllib2.HTTPError, urllib2.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 'lib/charmhelpers/contrib/charmsupport'
=== added file 'lib/charmhelpers/contrib/charmsupport/__init__.py'
=== added file 'lib/charmhelpers/contrib/charmsupport/nrpe.py'
--- lib/charmhelpers/contrib/charmsupport/nrpe.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/contrib/charmsupport/nrpe.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,219 @@
+"""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,
+)
+
+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.
+#
+# 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 = (
+            '/',
+            os.path.join(os.environ['CHARM_DIR'],
+                         'files/nrpe-external-master'),
+            '/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):
+        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)
+
+    def write_service_config(self, nagios_context, hostname):
+        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))
+
+        templ_vars = {
+            'nagios_hostname': hostname,
+            'nagios_servicegroup': nagios_context,
+            '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):
+        super(NRPE, self).__init__()
+        self.config = config()
+        self.nagios_context = self.config['nagios_context']
+        self.unit_name = local_unit().replace('/', '-')
+        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)
+            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))
 
=== added file 'lib/charmhelpers/contrib/charmsupport/volumes.py'
--- lib/charmhelpers/contrib/charmsupport/volumes.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/contrib/charmsupport/volumes.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,156 @@
+'''
+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 'lib/charmhelpers/contrib/hahelpers'
=== added file 'lib/charmhelpers/contrib/hahelpers/__init__.py'
=== added file 'lib/charmhelpers/contrib/hahelpers/apache.py'
--- lib/charmhelpers/contrib/hahelpers/apache.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/contrib/hahelpers/apache.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,58 @@
+#
+# 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():
+    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
+        for r_id in relation_ids('identity-service'):
+            for unit in relation_list(r_id):
+                if not cert:
+                    cert = relation_get('ssl_cert',
+                                        rid=r_id, unit=unit)
+                if not key:
+                    key = relation_get('ssl_key',
+                                       rid=r_id, unit=unit)
+    return (cert, key)
+
+
+def get_ca_cert():
+    ca_cert = 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 not ca_cert:
+                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 'lib/charmhelpers/contrib/hahelpers/cluster.py'
--- lib/charmhelpers/contrib/hahelpers/cluster.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/contrib/hahelpers/cluster.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,183 @@
+#
+# Copyright 2012 Canonical Ltd.
+#
+# Authors:
+#  James Page <[e-mail]>
+#  Adam Gandelman <[e-mail]>
+#
+
+import subprocess
+import os
+
+from socket import gethostname as get_unit_hostname
+
+from charmhelpers.core.hookenv import (
+    log,
+    relation_ids,
+    related_units as relation_list,
+    relation_get,
+    config as config_get,
+    INFO,
+    ERROR,
+    unit_get,
+)
+
+
+class HAIncompleteConfig(Exception):
+    pass
+
+
+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
+
+
+def is_leader(resource):
+    cmd = [
+        "crm", "resource",
+        "show", resource
+    ]
+    try:
+        status = subprocess.check_output(cmd)
+    except subprocess.CalledProcessError:
+        return False
+    else:
+        if get_unit_hostname() in status:
+            return True
+        else:
+            return False
+
+
+def peer_units():
+    peers = []
+    for r_id in (relation_ids('cluster') or []):
+        for unit in (relation_list(r_id) or []):
+            peers.append(unit)
+    return peers
+
+
+def oldest_peer(peers):
+    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):
+    if is_clustered():
+        if not is_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 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):
+            rel_state = [
+                relation_get('https_keystone', rid=r_id, unit=unit),
+                relation_get('ssl_cert', rid=r_id, unit=unit),
+                relation_get('ssl_key', 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):
+    '''
+    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
+
+    returns: int: the correct listening port for the API service
+    '''
+    i = 0
+    if len(peer_units()) > 0 or is_clustered():
+        i += 1
+    if https():
+        i += 1
+    return public_port - (i * 10)
+
+
+def determine_haproxy_port(public_port):
+    '''
+    Description: Determine correct proxy listening port based on public IP +
+    existence of HTTPS reverse proxy.
+
+    public_port: int: standard public port for given service
+
+    returns: int: the correct listening port for the HAProxy service
+    '''
+    i = 0
+    if https():
+        i += 1
+    return public_port - (i * 10)
+
+
+def get_hacluster_config():
+    '''
+    Obtains all relevant configuration from charm configuration required
+    for initiating a relation to hacluster:
+
+        ha-bindiface, ha-mcastport, vip, vip_iface, vip_cidr
+
+    returns: dict: A dict containing settings keyed by setting name.
+    raises: HAIncompleteConfig if settings are missing.
+    '''
+    settings = ['ha-bindiface', 'ha-mcastport', 'vip', 'vip_iface', 'vip_cidr']
+    conf = {}
+    for setting in settings:
+        conf[setting] = config_get(setting)
+    missing = []
+    [missing.append(s) for s, v in conf.iteritems() 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 'lib/charmhelpers/contrib/jujugui'
=== added file 'lib/charmhelpers/contrib/jujugui/__init__.py'
=== added file 'lib/charmhelpers/contrib/jujugui/utils.py'
--- lib/charmhelpers/contrib/jujugui/utils.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/contrib/jujugui/utils.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,602 @@
+"""Juju GUI charm utilities."""
+
+__all__ = [
+    'AGENT',
+    'APACHE',
+    'API_PORT',
+    'CURRENT_DIR',
+    'HAPROXY',
+    'IMPROV',
+    'JUJU_DIR',
+    'JUJU_GUI_DIR',
+    'JUJU_GUI_SITE',
+    'JUJU_PEM',
+    'WEB_PORT',
+    'bzr_checkout',
+    'chain',
+    'cmd_log',
+    'fetch_api',
+    'fetch_gui',
+    'find_missing_packages',
+    'first_path_in_dir',
+    'get_api_address',
+    'get_npm_cache_archive_url',
+    'get_release_file_url',
+    'get_staging_dependencies',
+    'get_zookeeper_address',
+    'legacy_juju',
+    'log_hook',
+    'merge',
+    'parse_source',
+    'prime_npm_cache',
+    'render_to_file',
+    'save_or_create_certificates',
+    'setup_apache',
+    'setup_gui',
+    'start_agent',
+    'start_gui',
+    'start_improv',
+    'write_apache_config',
+]
+
+from contextlib import contextmanager
+import errno
+import json
+import os
+import logging
+import shutil
+from subprocess import CalledProcessError
+import tempfile
+from urlparse import urlparse
+
+import apt
+import tempita
+
+from launchpadlib.launchpad import Launchpad
+from shelltoolbox import (
+    Serializer,
+    apt_get_install,
+    command,
+    environ,
+    install_extra_repositories,
+    run,
+    script_name,
+    search_file,
+    su,
+)
+from charmhelpers.core.host import (
+    service_start,
+)
+from charmhelpers.core.hookenv import (
+    log,
+    config,
+    unit_get,
+)
+
+
+AGENT = 'juju-api-agent'
+APACHE = 'apache2'
+IMPROV = 'juju-api-improv'
+HAPROXY = 'haproxy'
+
+API_PORT = 8080
+WEB_PORT = 8000
+
+CURRENT_DIR = os.getcwd()
+JUJU_DIR = os.path.join(CURRENT_DIR, 'juju')
+JUJU_GUI_DIR = os.path.join(CURRENT_DIR, 'juju-gui')
+JUJU_GUI_SITE = '/etc/apache2/sites-available/juju-gui'
+JUJU_GUI_PORTS = '/etc/apache2/ports.conf'
+JUJU_PEM = 'juju.includes-private-key.pem'
+BUILD_REPOSITORIES = ('ppa:chris-lea/node.js-legacy',)
+DEB_BUILD_DEPENDENCIES = (
+    'bzr', 'imagemagick', 'make', 'nodejs', 'npm',
+)
+DEB_STAGE_DEPENDENCIES = (
+    'zookeeper',
+)
+
+
+# Store the configuration from on invocation to the next.
+config_json = Serializer('/tmp/config.json')
+# Bazaar checkout command.
+bzr_checkout = command('bzr', 'co', '--lightweight')
+# Whether or not the charm is deployed using juju-core.
+# If juju-core has been used to deploy the charm, an agent.conf file must
+# be present in the charm parent directory.
+legacy_juju = lambda: not os.path.exists(
+    os.path.join(CURRENT_DIR, '..', 'agent.conf'))
+
+
+def _get_build_dependencies():
+    """Install deb dependencies for building."""
+    log('Installing build dependencies.')
+    cmd_log(install_extra_repositories(*BUILD_REPOSITORIES))
+    cmd_log(apt_get_install(*DEB_BUILD_DEPENDENCIES))
+
+
+def get_api_address(unit_dir):
+    """Return the Juju API address stored in the uniter agent.conf file."""
+    import yaml  # python-yaml is only installed if juju-core is used.
+    # XXX 2013-03-27 frankban bug=1161443:
+        # currently the uniter agent.conf file does not include the API
+        # address. For now retrieve it from the machine agent file.
+    base_dir = os.path.abspath(os.path.join(unit_dir, '..'))
+    for dirname in os.listdir(base_dir):
+        if dirname.startswith('machine-'):
+            agent_conf = os.path.join(base_dir, dirname, 'agent.conf')
+            break
+    else:
+        raise IOError('Juju agent configuration file not found.')
+    contents = yaml.load(open(agent_conf))
+    return contents['apiinfo']['addrs'][0]
+
+
+def get_staging_dependencies():
+    """Install deb dependencies for the stage (improv) environment."""
+    log('Installing stage dependencies.')
+    cmd_log(apt_get_install(*DEB_STAGE_DEPENDENCIES))
+
+
+def first_path_in_dir(directory):
+    """Return the full path of the first file/dir in *directory*."""
+    return os.path.join(directory, os.listdir(directory)[0])
+
+
+def _get_by_attr(collection, attr, value):
+    """Return the first item in collection having attr == value.
+
+    Return None if the item is not found.
+    """
+    for item in collection:
+        if getattr(item, attr) == value:
+            return item
+
+
+def get_release_file_url(project, series_name, release_version):
+    """Return the URL of the release file hosted in Launchpad.
+
+    The returned URL points to a release file for the given project, series
+    name and release version.
+    The argument *project* is a project object as returned by launchpadlib.
+    The arguments *series_name* and *release_version* are strings. If
+    *release_version* is None, the URL of the latest release will be returned.
+    """
+    series = _get_by_attr(project.series, 'name', series_name)
+    if series is None:
+        raise ValueError('%r: series not found' % series_name)
+    # Releases are returned by Launchpad in reverse date order.
+    releases = list(series.releases)
+    if not releases:
+        raise ValueError('%r: series does not contain releases' % series_name)
+    if release_version is not None:
+        release = _get_by_attr(releases, 'version', release_version)
+        if release is None:
+            raise ValueError('%r: release not found' % release_version)
+        releases = [release]
+    for release in releases:
+        for file_ in release.files:
+            if str(file_).endswith('.tgz'):
+                return file_.file_link
+    raise ValueError('%r: file not found' % release_version)
+
+
+def get_zookeeper_address(agent_file_path):
+    """Retrieve the Zookeeper address contained in the given *agent_file_path*.
+
+    The *agent_file_path* is a path to a file containing a line similar to the
+    following::
+
+        env JUJU_ZOOKEEPER="address"
+    """
+    line = search_file('JUJU_ZOOKEEPER', agent_file_path).strip()
+    return line.split('=')[1].strip('"')
+
+
+@contextmanager
+def log_hook():
+    """Log when a hook starts and stops its execution.
+
+    Also log to stdout possible CalledProcessError exceptions raised executing
+    the hook.
+    """
+    script = script_name()
+    log(">>> Entering {}".format(script))
+    try:
+        yield
+    except CalledProcessError as err:
+        log('Exception caught:')
+        log(err.output)
+        raise
+    finally:
+        log("<<< Exiting {}".format(script))
+
+
+def parse_source(source):
+    """Parse the ``juju-gui-source`` option.
+
+    Return a tuple of two elements representing info on how to deploy Juju GUI.
+    Examples:
+       - ('stable', None): latest stable release;
+       - ('stable', '0.1.0'): stable release v0.1.0;
+       - ('trunk', None): latest trunk release;
+       - ('trunk', '0.1.0+build.1'): trunk release v0.1.0 bzr revision 1;
+       - ('branch', 'lp:juju-gui'): release is made from a branch;
+       - ('url', 'http://example.com/gui'): release from a downloaded file.
+    """
+    if source.startswith('url:'):
+        source = source[4:]
+        # Support file paths, including relative paths.
+        if urlparse(source).scheme == '':
+            if not source.startswith('/'):
+                source = os.path.join(os.path.abspath(CURRENT_DIR), source)
+            source = "file://%s" % source
+        return 'url', source
+    if source in ('stable', 'trunk'):
+        return source, None
+    if source.startswith('lp:') or source.startswith('http://'):
+        return 'branch', source
+    if 'build' in source:
+        return 'trunk', source
+    return 'stable', source
+
+
+def render_to_file(template_name, context, destination):
+    """Render the given *template_name* into *destination* using *context*.
+
+    The tempita template language is used to render contents
+    (see http://pythonpaste.org/tempita/).
+    The argument *template_name* is the name or path of the template file:
+    it may be either a path relative to ``../config`` or an absolute path.
+    The argument *destination* is a file path.
+    The argument *context* is a dict-like object.
+    """
+    template_path = os.path.abspath(template_name)
+    template = tempita.Template.from_filename(template_path)
+    with open(destination, 'w') as stream:
+        stream.write(template.substitute(context))
+
+
+results_log = None
+
+
+def _setupLogging():
+    global results_log
+    if results_log is not None:
+        return
+    cfg = config()
+    logging.basicConfig(
+        filename=cfg['command-log-file'],
+        level=logging.INFO,
+        format="%(asctime)s: %(name)s@%(levelname)s %(message)s")
+    results_log = logging.getLogger('juju-gui')
+
+
+def cmd_log(results):
+    global results_log
+    if not results:
+        return
+    if results_log is None:
+        _setupLogging()
+    # Since 'results' may be multi-line output, start it on a separate line
+    # from the logger timestamp, etc.
+    results_log.info('\n' + results)
+
+
+def start_improv(staging_env, ssl_cert_path,
+                 config_path='/etc/init/juju-api-improv.conf'):
+    """Start a simulated juju environment using ``improv.py``."""
+    log('Setting up staging start up script.')
+    context = {
+        'juju_dir': JUJU_DIR,
+        'keys': ssl_cert_path,
+        'port': API_PORT,
+        'staging_env': staging_env,
+    }
+    render_to_file('config/juju-api-improv.conf.template', context, config_path)
+    log('Starting the staging backend.')
+    with su('root'):
+        service_start(IMPROV)
+
+
+def start_agent(
+        ssl_cert_path, config_path='/etc/init/juju-api-agent.conf',
+        read_only=False):
+    """Start the Juju agent and connect to the current environment."""
+    # Retrieve the Zookeeper address from the start up script.
+    unit_dir = os.path.realpath(os.path.join(CURRENT_DIR, '..'))
+    agent_file = '/etc/init/juju-{0}.conf'.format(os.path.basename(unit_dir))
+    zookeeper = get_zookeeper_address(agent_file)
+    log('Setting up API agent start up script.')
+    context = {
+        'juju_dir': JUJU_DIR,
+        'keys': ssl_cert_path,
+        'port': API_PORT,
+        'zookeeper': zookeeper,
+        'read_only': read_only
+    }
+    render_to_file('config/juju-api-agent.conf.template', context, config_path)
+    log('Starting API agent.')
+    with su('root'):
+        service_start(AGENT)
+
+
+def start_gui(
+        console_enabled, login_help, readonly, in_staging, ssl_cert_path,
+        charmworld_url, serve_tests, haproxy_path='/etc/haproxy/haproxy.cfg',
+        config_js_path=None, secure=True, sandbox=False):
+    """Set up and start the Juju GUI server."""
+    with su('root'):
+        run('chown', '-R', 'ubuntu:', JUJU_GUI_DIR)
+    # XXX 2013-02-05 frankban bug=1116320:
+        # External insecure resources are still loaded when testing in the
+        # debug environment. For now, switch to the production environment if
+        # the charm is configured to serve tests.
+    if in_staging and not serve_tests:
+        build_dirname = 'build-debug'
+    else:
+        build_dirname = 'build-prod'
+    build_dir = os.path.join(JUJU_GUI_DIR, build_dirname)
+    log('Generating the Juju GUI configuration file.')
+    is_legacy_juju = legacy_juju()
+    user, password = None, None
+    if (is_legacy_juju and in_staging) or sandbox:
+        user, password = 'admin', 'admin'
+    else:
+        user, password = None, None
+
+    api_backend = 'python' if is_legacy_juju else 'go'
+    if secure:
+        protocol = 'wss'
+    else:
+        log('Running in insecure mode! Port 80 will serve unencrypted.')
+        protocol = 'ws'
+
+    context = {
+        'raw_protocol': protocol,
+        'address': unit_get('public-address'),
+        'console_enabled': json.dumps(console_enabled),
+        'login_help': json.dumps(login_help),
+        'password': json.dumps(password),
+        'api_backend': json.dumps(api_backend),
+        'readonly': json.dumps(readonly),
+        'user': json.dumps(user),
+        'protocol': json.dumps(protocol),
+        'sandbox': json.dumps(sandbox),
+        'charmworld_url': json.dumps(charmworld_url),
+    }
+    if config_js_path is None:
+        config_js_path = os.path.join(
+            build_dir, 'juju-ui', 'assets', 'config.js')
+    render_to_file('config/config.js.template', context, config_js_path)
+
+    write_apache_config(build_dir, serve_tests)
+
+    log('Generating haproxy configuration file.')
+    if is_legacy_juju:
+        # The PyJuju API agent is listening on localhost.
+        api_address = '127.0.0.1:{0}'.format(API_PORT)
+    else:
+        # Retrieve the juju-core API server address.
+        api_address = get_api_address(os.path.join(CURRENT_DIR, '..'))
+    context = {
+        'api_address': api_address,
+        'api_pem': JUJU_PEM,
+        'legacy_juju': is_legacy_juju,
+        'ssl_cert_path': ssl_cert_path,
+        # In PyJuju environments, use the same certificate for both HTTPS and
+        # WebSocket connections. In juju-core the system already has the proper
+        # certificate installed.
+        'web_pem': JUJU_PEM,
+        'web_port': WEB_PORT,
+        'secure': secure
+    }
+    render_to_file('config/haproxy.cfg.template', context, haproxy_path)
+    log('Starting Juju GUI.')
+
+
+def write_apache_config(build_dir, serve_tests=False):
+    log('Generating the apache site configuration file.')
+    context = {
+        'port': WEB_PORT,
+        'serve_tests': serve_tests,
+        'server_root': build_dir,
+        'tests_root': os.path.join(JUJU_GUI_DIR, 'test', ''),
+    }
+    render_to_file('config/apache-ports.template', context, JUJU_GUI_PORTS)
+    render_to_file('config/apache-site.template', context, JUJU_GUI_SITE)
+
+
+def get_npm_cache_archive_url(Launchpad=Launchpad):
+    """Figure out the URL of the most recent NPM cache archive on Launchpad."""
+    launchpad = Launchpad.login_anonymously('Juju GUI charm', 'production')
+    project = launchpad.projects['juju-gui']
+    # Find the URL of the most recently created NPM cache archive.
+    npm_cache_url = get_release_file_url(project, 'npm-cache', None)
+    return npm_cache_url
+
+
+def prime_npm_cache(npm_cache_url):
+    """Download NPM cache archive and prime the NPM cache with it."""
+    # Download the cache archive and then uncompress it into the NPM cache.
+    npm_cache_archive = os.path.join(CURRENT_DIR, 'npm-cache.tgz')
+    cmd_log(run('curl', '-L', '-o', npm_cache_archive, npm_cache_url))
+    npm_cache_dir = os.path.expanduser('~/.npm')
+    # The NPM cache directory probably does not exist, so make it if not.
+    try:
+        os.mkdir(npm_cache_dir)
+    except OSError, e:
+        # If the directory already exists then ignore the error.
+        if e.errno != errno.EEXIST:  # File exists.
+            raise
+    uncompress = command('tar', '-x', '-z', '-C', npm_cache_dir, '-f')
+    cmd_log(uncompress(npm_cache_archive))
+
+
+def fetch_gui(juju_gui_source, logpath):
+    """Retrieve the Juju GUI release/branch."""
+    # Retrieve a Juju GUI release.
+    origin, version_or_branch = parse_source(juju_gui_source)
+    if origin == 'branch':
+        # Make sure we have the dependencies necessary for us to actually make
+        # a build.
+        _get_build_dependencies()
+        # Create a release starting from a branch.
+        juju_gui_source_dir = os.path.join(CURRENT_DIR, 'juju-gui-source')
+        log('Retrieving Juju GUI source checkout from %s.' % version_or_branch)
+        cmd_log(run('rm', '-rf', juju_gui_source_dir))
+        cmd_log(bzr_checkout(version_or_branch, juju_gui_source_dir))
+        log('Preparing a Juju GUI release.')
+        logdir = os.path.dirname(logpath)
+        fd, name = tempfile.mkstemp(prefix='make-distfile-', dir=logdir)
+        log('Output from "make distfile" sent to %s' % name)
+        with environ(NO_BZR='1'):
+            run('make', '-C', juju_gui_source_dir, 'distfile',
+                stdout=fd, stderr=fd)
+        release_tarball = first_path_in_dir(
+            os.path.join(juju_gui_source_dir, 'releases'))
+    else:
+        log('Retrieving Juju GUI release.')
+        if origin == 'url':
+            file_url = version_or_branch
+        else:
+            # Retrieve a release from Launchpad.
+            launchpad = Launchpad.login_anonymously(
+                'Juju GUI charm', 'production')
+            project = launchpad.projects['juju-gui']
+            file_url = get_release_file_url(project, origin, version_or_branch)
+        log('Downloading release file from %s.' % file_url)
+        release_tarball = os.path.join(CURRENT_DIR, 'release.tgz')
+        cmd_log(run('curl', '-L', '-o', release_tarball, file_url))
+    return release_tarball
+
+
+def fetch_api(juju_api_branch):
+    """Retrieve the Juju branch."""
+    # Retrieve Juju API source checkout.
+    log('Retrieving Juju API source checkout.')
+    cmd_log(run('rm', '-rf', JUJU_DIR))
+    cmd_log(bzr_checkout(juju_api_branch, JUJU_DIR))
+
+
+def setup_gui(release_tarball):
+    """Set up Juju GUI."""
+    # Uncompress the release tarball.
+    log('Installing Juju GUI.')
+    release_dir = os.path.join(CURRENT_DIR, 'release')
+    cmd_log(run('rm', '-rf', release_dir))
+    os.mkdir(release_dir)
+    uncompress = command('tar', '-x', '-z', '-C', release_dir, '-f')
+    cmd_log(uncompress(release_tarball))
+    # Link the Juju GUI dir to the contents of the release tarball.
+    cmd_log(run('ln', '-sf', first_path_in_dir(release_dir), JUJU_GUI_DIR))
+
+
+def setup_apache():
+    """Set up apache."""
+    log('Setting up apache.')
+    if not os.path.exists(JUJU_GUI_SITE):
+        cmd_log(run('touch', JUJU_GUI_SITE))
+        cmd_log(run('chown', 'ubuntu:', JUJU_GUI_SITE))
+        cmd_log(
+            run('ln', '-s', JUJU_GUI_SITE,
+                '/etc/apache2/sites-enabled/juju-gui'))
+
+    if not os.path.exists(JUJU_GUI_PORTS):
+        cmd_log(run('touch', JUJU_GUI_PORTS))
+        cmd_log(run('chown', 'ubuntu:', JUJU_GUI_PORTS))
+
+    with su('root'):
+        run('a2dissite', 'default')
+        run('a2ensite', 'juju-gui')
+
+
+def save_or_create_certificates(
+        ssl_cert_path, ssl_cert_contents, ssl_key_contents):
+    """Generate the SSL certificates.
+
+    If both *ssl_cert_contents* and *ssl_key_contents* are provided, use them
+    as certificates; otherwise, generate them.
+
+    Also create a pem file, suitable for use in the haproxy configuration,
+    concatenating the key and the certificate files.
+    """
+    crt_path = os.path.join(ssl_cert_path, 'juju.crt')
+    key_path = os.path.join(ssl_cert_path, 'juju.key')
+    if not os.path.exists(ssl_cert_path):
+        os.makedirs(ssl_cert_path)
+    if ssl_cert_contents and ssl_key_contents:
+        # Save the provided certificates.
+        with open(crt_path, 'w') as cert_file:
+            cert_file.write(ssl_cert_contents)
+        with open(key_path, 'w') as key_file:
+            key_file.write(ssl_key_contents)
+    else:
+        # Generate certificates.
+        # See http://superuser.com/questions/226192/openssl-without-prompt
+        cmd_log(run(
+            'openssl', 'req', '-new', '-newkey', 'rsa:4096',
+            '-days', '365', '-nodes', '-x509', '-subj',
+            # These are arbitrary test values for the certificate.
+            '/C=GB/ST=Juju/L=GUI/O=Ubuntu/CN=juju.ubuntu.com',
+            '-keyout', key_path, '-out', crt_path))
+    # Generate the pem file.
+    pem_path = os.path.join(ssl_cert_path, JUJU_PEM)
+    if os.path.exists(pem_path):
+        os.remove(pem_path)
+    with open(pem_path, 'w') as pem_file:
+        shutil.copyfileobj(open(key_path), pem_file)
+        shutil.copyfileobj(open(crt_path), pem_file)
+
+
+def find_missing_packages(*packages):
+    """Given a list of packages, return the packages which are not installed.
+    """
+    cache = apt.Cache()
+    missing = set()
+    for pkg_name in packages:
+        try:
+            pkg = cache[pkg_name]
+        except KeyError:
+            missing.add(pkg_name)
+            continue
+        if pkg.is_installed:
+            continue
+        missing.add(pkg_name)
+    return missing
+
+
+## Backend support decorators
+
+def chain(name):
+    """Helper method to compose a set of mixin objects into a callable.
+
+    Each method is called in the context of its mixin instance, and its
+    argument is the Backend instance.
+    """
+    # Chain method calls through all implementing mixins.
+    def method(self):
+        for mixin in self.mixins:
+            a_callable = getattr(type(mixin), name, None)
+            if a_callable:
+                a_callable(mixin, self)
+
+    method.__name__ = name
+    return method
+
+
+def merge(name):
+    """Helper to merge a property from a set of strategy objects
+    into a unified set.
+    """
+    # Return merged property from every providing mixin as a set.
+    @property
+    def method(self):
+        result = set()
+        for mixin in self.mixins:
+            segment = getattr(type(mixin), name, None)
+            if segment and isinstance(segment, (list, tuple, set)):
+                result |= set(segment)
+
+        return result
+    return method
 
=== added directory 'lib/charmhelpers/contrib/saltstack'
=== added file 'lib/charmhelpers/contrib/saltstack/__init__.py'
--- lib/charmhelpers/contrib/saltstack/__init__.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/contrib/saltstack/__init__.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,149 @@
+"""Charm Helpers saltstack - 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:
+
+{{{
+from charmhelpers.contrib.saltstack import (
+    install_salt_support,
+    update_machine_state,
+)
+
+
+def install():
+    install_salt_support()
+    update_machine_state('machine_states/dependencies.yaml')
+    update_machine_state('machine_states/installed.yaml')
+}}}
+
+and won't need to change (nor will its tests) when you change the machine
+state.
+
+It's using a python package called salt-minion which allows various formats for
+specifying resources, such as:
+
+{{{
+/srv/{{ basedir }}:
+    file.directory:
+        - group: ubunet
+        - user: ubunet
+        - require:
+            - user: ubunet
+        - recurse:
+            - user
+            - group
+
+ubunet:
+    group.present:
+        - gid: 1500
+    user.present:
+        - uid: 1500
+        - gid: 1500
+        - createhome: False
+        - require:
+            - group: ubunet
+}}}
+
+The docs for all the different state definitions are at:
+    http://docs.saltstack.com/ref/states/all/
+
+
+TODO:
+  * Add test helpers which will ensure that machine state definitions
+    are functionally (but not necessarily logically) correct (ie. getting
+    salt to parse all state defs.
+  * Add a link to a public bootstrap charm example / blogpost.
+  * Find a way to obviate the need to use the grains['charm_dir'] syntax
+    in templates.
+"""
+# Copyright 2013 Canonical Ltd.
+#
+# Authors:
+#  Charm Helpers Developers <[e-mail]>
+import os
+import subprocess
+import yaml
+
+import charmhelpers.core.host
+import charmhelpers.core.hookenv
+
+
+charm_dir = os.environ.get('CHARM_DIR', '')
+salt_grains_path = '/etc/salt/grains'
+
+
+def install_salt_support(from_ppa=True):
+    """Installs the salt-minion helper for machine state.
+
+    By default the salt-minion package is installed from
+    the saltstack PPA. If from_ppa is False you must ensure
+    that the salt-minion package is available in the apt cache.
+    """
+    if from_ppa:
+        subprocess.check_call([
+            '/usr/bin/add-apt-repository',
+            '--yes',
+            'ppa:saltstack/salt',
+        ])
+        subprocess.check_call(['/usr/bin/apt-get', 'update'])
+    # We install salt-common as salt-minion would run the salt-minion
+    # daemon.
+    charmhelpers.fetch.apt_install('salt-common')
+
+
+def update_machine_state(state_path):
+    """Update the machine state using the provided state declaration."""
+    juju_state_to_yaml(salt_grains_path)
+    subprocess.check_call([
+        'salt-call',
+        '--local',
+        'state.template',
+        state_path,
+    ])
+
+
+def juju_state_to_yaml(yaml_path, namespace_separator=':'):
+    """Update the juju config and state in a yaml file.
+
+    This includes any current relation-get data, and the charm
+    directory.
+    """
+    config = charmhelpers.core.hookenv.config()
+
+    # Add the charm_dir which we will need to refer to charm
+    # file resources etc.
+    config['charm_dir'] = charm_dir
+    config['local_unit'] = charmhelpers.core.hookenv.local_unit()
+
+    # Add any relation data prefixed with the relation type.
+    relation_type = charmhelpers.core.hookenv.relation_type()
+    if relation_type is not None:
+        relation_data = charmhelpers.core.hookenv.relation_get()
+        relation_data = dict(
+            ("{relation_type}{namespace_separator}{key}".format(
+                relation_type=relation_type.replace('-', '_'),
+                key=key,
+                namespace_separator=namespace_separator), val)
+            for key, val in relation_data.items())
+        config.update(relation_data)
+
+    # Don't use non-standard tags for unicode which will not
+    # work when salt uses yaml.load_safe.
+    yaml.add_representer(unicode, lambda dumper,
+                         value: dumper.represent_scalar(
+                             u'tag:yaml.org,2002:str', value))
+
+    yaml_dir = os.path.dirname(yaml_path)
+    if not os.path.exists(yaml_dir):
+        os.makedirs(yaml_dir)
+
+    if os.path.exists(yaml_path):
+        with open(yaml_path, "r") as existing_vars_file:
+            existing_vars = yaml.load(existing_vars_file.read())
+    else:
+        existing_vars = {}
+
+    existing_vars.update(config)
+    with open(yaml_path, "w+") as fp:
+        fp.write(yaml.dump(existing_vars))
 
=== added directory 'lib/charmhelpers/core'
=== added file 'lib/charmhelpers/core/__init__.py'
=== added file 'lib/charmhelpers/core/hookenv.py'
--- lib/charmhelpers/core/hookenv.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/core/hookenv.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,395 @@
+"Interactions with the Juju environment"
+# Copyright 2013 Canonical Ltd.
+#
+# Authors:
+#  Charm Helpers Developers <[e-mail]>
+
+import os
+import json
+import yaml
+import subprocess
+import UserDict
+from subprocess import CalledProcessError
+
+CRITICAL = "CRITICAL"
+ERROR = "ERROR"
+WARNING = "WARNING"
+INFO = "INFO"
+DEBUG = "DEBUG"
+MARKER = object()
+
+cache = {}
+
+
+def cached(func):
+    """Cache return values for multiple executions of func + args
+
+    For example:
+
+        @cached
+        def unit_get(attribute):
+            pass
+
+        unit_get('test')
+
+    will cache the result of unit_get + 'test' for future calls.
+    """
+    def wrapper(*args, **kwargs):
+        global cache
+        key = str((func, args, kwargs))
+        try:
+            return cache[key]
+        except KeyError:
+            res = func(*args, **kwargs)
+            cache[key] = res
+            return res
+    return wrapper
+
+
+def flush(key):
+    """Flushes any entries from function cache where the
+    key is found in the function+args """
+    flush_list = []
+    for item in cache:
+        if key in item:
+            flush_list.append(item)
+    for item in flush_list:
+        del cache[item]
+
+
+def log(message, level=None):
+    """Write a message to the juju log"""
+    command = ['juju-log']
+    if level:
+        command += ['-l', level]
+    command += [message]
+    subprocess.call(command)
+
+
+class Serializable(UserDict.IterableUserDict):
+    """Wrapper, an object that can be serialized to yaml or json"""
+
+    def __init__(self, obj):
+        # wrap the object
+        UserDict.IterableUserDict.__init__(self)
+        self.data = obj
+
+    def __getattr__(self, attr):
+        # See if this object has attribute.
+        if attr in ("json", "yaml", "data"):
+            return self.__dict__[attr]
+        # Check for attribute in wrapped object.
+        got = getattr(self.data, attr, MARKER)
+        if got is not MARKER:
+            return got
+        # Proxy to the wrapped object via dict interface.
+        try:
+            return self.data[attr]
+        except KeyError:
+            raise AttributeError(attr)
+
+    def __getstate__(self):
+        # Pickle as a standard dictionary.
+        return self.data
+
+    def __setstate__(self, state):
+        # Unpickle into our wrapper.
+        self.data = state
+
+    def json(self):
+        """Serialize the object to json"""
+        return json.dumps(self.data)
+
+    def yaml(self):
+        """Serialize the object to yaml"""
+        return yaml.dump(self.data)
+
+
+def execution_environment():
+    """A convenient bundling of the current execution context"""
+    context = {}
+    context['conf'] = config()
+    if relation_id():
+        context['reltype'] = relation_type()
+        context['relid'] = relation_id()
+        context['rel'] = relation_get()
+    context['unit'] = local_unit()
+    context['rels'] = relations()
+    context['env'] = os.environ
+    return context
+
+
+def in_relation_hook():
+    """Determine whether we're running in a relation hook"""
+    return 'JUJU_RELATION' in os.environ
+
+
+def relation_type():
+    """The scope for the current relation hook"""
+    return os.environ.get('JUJU_RELATION', None)
+
+
+def relation_id():
+    """The relation ID for the current relation hook"""
+    return os.environ.get('JUJU_RELATION_ID', None)
+
+
+def local_unit():
+    """Local unit ID"""
+    return os.environ['JUJU_UNIT_NAME']
+
+
+def remote_unit():
+    """The remote unit for the current relation hook"""
+    return os.environ['JUJU_REMOTE_UNIT']
+
+
+def service_name():
+    """The name service group this unit belongs to"""
+    return local_unit().split('/')[0]
+
+
+@cached
+def config(scope=None):
+    """Juju charm configuration"""
+    config_cmd_line = ['config-get']
+    if scope is not None:
+        config_cmd_line.append(scope)
+    config_cmd_line.append('--format=json')
+    try:
+        return json.loads(subprocess.check_output(config_cmd_line))
+    except ValueError:
+        return None
+
+
+@cached
+def relation_get(attribute=None, unit=None, rid=None):
+    """Get relation information"""
+    _args = ['relation-get', '--format=json']
+    if rid:
+        _args.append('-r')
+        _args.append(rid)
+    _args.append(attribute or '-')
+    if unit:
+        _args.append(unit)
+    try:
+        return json.loads(subprocess.check_output(_args))
+    except ValueError:
+        return None
+    except CalledProcessError, e:
+        if e.returncode == 2:
+            return None
+        raise
+
+
+def relation_set(relation_id=None, relation_settings={}, **kwargs):
+    """Set relation information for the current unit"""
+    relation_cmd_line = ['relation-set']
+    if relation_id is not None:
+        relation_cmd_line.extend(('-r', relation_id))
+    for k, v in (relation_settings.items() + kwargs.items()):
+        if v is None:
+            relation_cmd_line.append('{}='.format(k))
+        else:
+            relation_cmd_line.append('{}={}'.format(k, v))
+    subprocess.check_call(relation_cmd_line)
+    # Flush cache of any relation-gets for local unit
+    flush(local_unit())
+
+
+@cached
+def relation_ids(reltype=None):
+    """A list of relation_ids"""
+    reltype = reltype or relation_type()
+    relid_cmd_line = ['relation-ids', '--format=json']
+    if reltype is not None:
+        relid_cmd_line.append(reltype)
+        return json.loads(subprocess.check_output(relid_cmd_line)) or []
+    return []
+
+
+@cached
+def related_units(relid=None):
+    """A list of related units"""
+    relid = relid or relation_id()
+    units_cmd_line = ['relation-list', '--format=json']
+    if relid is not None:
+        units_cmd_line.extend(('-r', relid))
+    return json.loads(subprocess.check_output(units_cmd_line)) or []
+
+
+@cached
+def relation_for_unit(unit=None, rid=None):
+    """Get the json represenation of a unit's relation"""
+    unit = unit or remote_unit()
+    relation = relation_get(unit=unit, rid=rid)
+    for key in relation:
+        if key.endswith('-list'):
+            relation[key] = relation[key].split()
+    relation['__unit__'] = unit
+    return relation
+
+
+@cached
+def relations_for_id(relid=None):
+    """Get relations of a specific relation ID"""
+    relation_data = []
+    relid = relid or relation_ids()
+    for unit in related_units(relid):
+        unit_data = relation_for_unit(unit, relid)
+        unit_data['__relid__'] = relid
+        relation_data.append(unit_data)
+    return relation_data
+
+
+@cached
+def relations_of_type(reltype=None):
+    """Get relations of a specific type"""
+    relation_data = []
+    reltype = reltype or relation_type()
+    for relid in relation_ids(reltype):
+        for relation in relations_for_id(relid):
+            relation['__relid__'] = relid
+            relation_data.append(relation)
+    return relation_data
+
+
+@cached
+def relation_types():
+    """Get a list of relation types supported by this charm"""
+    charmdir = os.environ.get('CHARM_DIR', '')
+    mdf = open(os.path.join(charmdir, 'metadata.yaml'))
+    md = yaml.safe_load(mdf)
+    rel_types = []
+    for key in ('provides', 'requires', 'peers'):
+        section = md.get(key)
+        if section:
+            rel_types.extend(section.keys())
+    mdf.close()
+    return rel_types
+
+
+@cached
+def relations():
+    """Get a nested dictionary of relation data for all related units"""
+    rels = {}
+    for reltype in relation_types():
+        relids = {}
+        for relid in relation_ids(reltype):
+            units = {local_unit(): relation_get(unit=local_unit(), rid=relid)}
+            for unit in related_units(relid):
+                reldata = relation_get(unit=unit, rid=relid)
+                units[unit] = reldata
+            relids[relid] = units
+        rels[reltype] = relids
+    return rels
+
+
+@cached
+def is_relation_made(relation, keys='private-address'):
+    '''
+    Determine whether a relation is established by checking for
+    presence of key(s).  If a list of keys is provided, they
+    must all be present for the relation to be identified as made
+    '''
+    if isinstance(keys, str):
+        keys = [keys]
+    for r_id in relation_ids(relation):
+        for unit in related_units(r_id):
+            context = {}
+            for k in keys:
+                context[k] = relation_get(k, rid=r_id,
+                                          unit=unit)
+            if None not in context.values():
+                return True
+    return False
+
+
+def open_port(port, protocol="TCP"):
+    """Open a service network port"""
+    _args = ['open-port']
+    _args.append('{}/{}'.format(port, protocol))
+    subprocess.check_call(_args)
+
+
+def close_port(port, protocol="TCP"):
+    """Close a service network port"""
+    _args = ['close-port']
+    _args.append('{}/{}'.format(port, protocol))
+    subprocess.check_call(_args)
+
+
+@cached
+def unit_get(attribute):
+    """Get the unit ID for the remote unit"""
+    _args = ['unit-get', '--format=json', attribute]
+    try:
+        return json.loads(subprocess.check_output(_args))
+    except ValueError:
+        return None
+
+
+def unit_private_ip():
+    """Get this unit's private IP address"""
+    return unit_get('private-address')
+
+
+class UnregisteredHookError(Exception):
+    """Raised when an undefined hook is called"""
+    pass
+
+
+class Hooks(object):
+    """A convenient handler for hook functions.
+
+    Example:
+        hooks = Hooks()
+
+        # register a hook, taking its name from the function name
+        @hooks.hook()
+        def install():
+            ...
+
+        # register a hook, providing a custom hook name
+        @hooks.hook("config-changed")
+        def config_changed():
+            ...
+
+        if __name__ == "__main__":
+            # execute a hook based on the name the program is called by
+            hooks.execute(sys.argv)
+    """
+
+    def __init__(self):
+        super(Hooks, self).__init__()
+        self._hooks = {}
+
+    def register(self, name, function):
+        """Register a hook"""
+        self._hooks[name] = function
+
+    def execute(self, args):
+        """Execute a registered hook based on args[0]"""
+        hook_name = os.path.basename(args[0])
+        if hook_name in self._hooks:
+            self._hooks[hook_name]()
+        else:
+            raise UnregisteredHookError(hook_name)
+
+    def hook(self, *hook_names):
+        """Decorator, registering them as hooks"""
+        def wrapper(decorated):
+            for hook_name in hook_names:
+                self.register(hook_name, decorated)
+            else:
+                self.register(decorated.__name__, decorated)
+                if '_' in decorated.__name__:
+                    self.register(
+                        decorated.__name__.replace('_', '-'), decorated)
+            return decorated
+        return wrapper
+
+
+def charm_dir():
+    """Return the root directory of the current charm"""
+    return os.environ.get('CHARM_DIR')
 
=== added file 'lib/charmhelpers/core/host.py'
--- lib/charmhelpers/core/host.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/core/host.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,281 @@
+"""Tools for working with the host system"""
+# Copyright 2012 Canonical Ltd.
+#
+# Authors:
+#  Nick Moffitt <[e-mail]>
+#  Matthew Wedgwood <[e-mail]>
+
+import os
+import pwd
+import grp
+import random
+import string
+import subprocess
+import hashlib
+
+from collections import OrderedDict
+
+from hookenv import log
+
+
+def service_start(service_name):
+    """Start a system service"""
+    return service('start', service_name)
+
+
+def service_stop(service_name):
+    """Stop a system service"""
+    return service('stop', service_name)
+
+
+def service_restart(service_name):
+    """Restart a system service"""
+    return service('restart', service_name)
+
+
+def service_reload(service_name, restart_on_failure=False):
+    """Reload a system service, optionally falling back to restart if reload fails"""
+    service_result = service('reload', service_name)
+    if not service_result and restart_on_failure:
+        service_result = service('restart', service_name)
+    return service_result
+
+
+def service(action, service_name):
+    """Control a system service"""
+    cmd = ['service', service_name, action]
+    return subprocess.call(cmd) == 0
+
+
+def service_running(service):
+    """Determine whether a system service is running"""
+    try:
+        output = subprocess.check_output(['service', service, 'status'])
+    except subprocess.CalledProcessError:
+        return False
+    else:
+        if ("start/running" in output or "is running" in output):
+            return True
+        else:
+            return False
+
+
+def adduser(username, password=None, shell='/bin/bash', system_user=False):
+    """Add a user to the system"""
+    try:
+        user_info = pwd.getpwnam(username)
+        log('user {0} already exists!'.format(username))
+    except KeyError:
+        log('creating user {0}'.format(username))
+        cmd = ['useradd']
+        if system_user or password is None:
+            cmd.append('--system')
+        else:
+            cmd.extend([
+                '--create-home',
+                '--shell', shell,
+                '--password', password,
+            ])
+        cmd.append(username)
+        subprocess.check_call(cmd)
+        user_info = pwd.getpwnam(username)
+    return user_info
+
+
+def add_user_to_group(username, group):
+    """Add a user to a group"""
+    cmd = [
+        'gpasswd', '-a',
+        username,
+        group
+    ]
+    log("Adding user {} to group {}".format(username, group))
+    subprocess.check_call(cmd)
+
+
+def rsync(from_path, to_path, flags='-r', options=None):
+    """Replicate the contents of a path"""
+    options = options or ['--delete', '--executability']
+    cmd = ['/usr/bin/rsync', flags]
+    cmd.extend(options)
+    cmd.append(from_path)
+    cmd.append(to_path)
+    log(" ".join(cmd))
+    return subprocess.check_output(cmd).strip()
+
+
+def symlink(source, destination):
+    """Create a symbolic link"""
+    log("Symlinking {} as {}".format(source, destination))
+    cmd = [
+        'ln',
+        '-sf',
+        source,
+        destination,
+    ]
+    subprocess.check_call(cmd)
+
+
+def mkdir(path, owner='root', group='root', perms=0555, force=False):
+    """Create a directory"""
+    log("Making dir {} {}:{} {:o}".format(path, owner, group,
+                                          perms))
+    uid = pwd.getpwnam(owner).pw_uid
+    gid = grp.getgrnam(group).gr_gid
+    realpath = os.path.abspath(path)
+    if os.path.exists(realpath):
+        if force and not os.path.isdir(realpath):
+            log("Removing non-directory file {} prior to mkdir()".format(path))
+            os.unlink(realpath)
+    else:
+        os.makedirs(realpath, perms)
+    os.chown(realpath, uid, gid)
+
+
+def write_file(path, content, owner='root', group='root', perms=0444):
+    """Create or overwrite a file with the contents of a string"""
+    log("Writing file {} {}:{} {:o}".format(path, owner, group, perms))
+    uid = pwd.getpwnam(owner).pw_uid
+    gid = grp.getgrnam(group).gr_gid
+    with open(path, 'w') as target:
+        os.fchown(target.fileno(), uid, gid)
+        os.fchmod(target.fileno(), perms)
+        target.write(content)
+
+
+def mount(device, mountpoint, options=None, persist=False):
+    """Mount a filesystem at a particular mountpoint"""
+    cmd_args = ['mount']
+    if options is not None:
+        cmd_args.extend(['-o', options])
+    cmd_args.extend([device, mountpoint])
+    try:
+        subprocess.check_output(cmd_args)
+    except subprocess.CalledProcessError, e:
+        log('Error mounting {} at {}\n{}'.format(device, mountpoint, e.output))
+        return False
+    if persist:
+        # TODO: update fstab
+        pass
+    return True
+
+
+def umount(mountpoint, persist=False):
+    """Unmount a filesystem"""
+    cmd_args = ['umount', mountpoint]
+    try:
+        subprocess.check_output(cmd_args)
+    except subprocess.CalledProcessError, e:
+        log('Error unmounting {}\n{}'.format(mountpoint, e.output))
+        return False
+    if persist:
+        # TODO: update fstab
+        pass
+    return True
+
+
+def mounts():
+    """Get a list of all mounted volumes as [[mountpoint,device],[...]]"""
+    with open('/proc/mounts') as f:
+        # [['/mount/point','/dev/path'],[...]]
+        system_mounts = [m[1::-1] for m in [l.strip().split()
+                                            for l in f.readlines()]]
+    return system_mounts
+
+
+def file_hash(path):
+    """Generate a md5 hash of the contents of 'path' or None if not found """
+    if os.path.exists(path):
+        h = hashlib.md5()
+        with open(path, 'r') as source:
+            h.update(source.read())  # IGNORE:E1101 - it does have update
+        return h.hexdigest()
+    else:
+        return None
+
+
+def restart_on_change(restart_map):
+    """Restart services based on configuration files changing
+
+    This function is used a decorator, for example
+
+        @restart_on_change({
+            '/etc/ceph/ceph.conf': [ 'cinder-api', 'cinder-volume' ]
+            })
+        def ceph_client_changed():
+            ...
+
+    In this example, the cinder-api and cinder-volume services
+    would be restarted if /etc/ceph/ceph.conf is changed by the
+    ceph_client_changed function.
+    """
+    def wrap(f):
+        def wrapped_f(*args):
+            checksums = {}
+            for path in restart_map:
+                checksums[path] = file_hash(path)
+            f(*args)
+            restarts = []
+            for path in restart_map:
+                if checksums[path] != file_hash(path):
+                    restarts += restart_map[path]
+            for service_name in list(OrderedDict.fromkeys(restarts)):
+                service('restart', service_name)
+        return wrapped_f
+    return wrap
+
+
+def lsb_release():
+    """Return /etc/lsb-release in a dict"""
+    d = {}
+    with open('/etc/lsb-release', 'r') as lsb:
+        for l in lsb:
+            k, v = l.split('=')
+            d[k.strip()] = v.strip()
+    return d
+
+
+def pwgen(length=None):
+    """Generate a random pasword."""
+    if length is None:
+        length = random.choice(range(35, 45))
+    alphanumeric_chars = [
+        l for l in (string.letters + string.digits)
+        if l not in 'l0QD1vAEIOUaeiou']
+    random_chars = [
+        random.choice(alphanumeric_chars) for _ in range(length)]
+    return(''.join(random_chars))
+
+
+def list_nics(nic_type):
+    '''Return a list of nics of given type(s)'''
+    if isinstance(nic_type, basestring):
+        int_types = [nic_type]
+    else:
+        int_types = nic_type
+    interfaces = []
+    for int_type in int_types:
+        cmd = ['ip', 'addr', 'show', 'label', int_type + '*']
+        ip_output = subprocess.check_output(cmd).split('\n')
+        ip_output = (line for line in ip_output if line)
+        for line in ip_output:
+            if line.split()[1].startswith(int_type):
+                interfaces.append(line.split()[1].replace(":", ""))
+    return interfaces
+
+
+def set_nic_mtu(nic, mtu):
+    '''Set MTU on a network interface'''
+    cmd = ['ip', 'link', 'set', nic, 'mtu', mtu]
+    subprocess.check_call(cmd)
+
+
+def get_nic_mtu(nic):
+    cmd = ['ip', 'addr', 'show', nic]
+    ip_output = subprocess.check_output(cmd).split('\n')
+    mtu = ""
+    for line in ip_output:
+        words = line.split()
+        if 'mtu' in words:
+            mtu = words[words.index("mtu") + 1]
+    return mtu
 
=== added directory 'lib/charmhelpers/fetch'
=== added file 'lib/charmhelpers/fetch/__init__.py'
--- lib/charmhelpers/fetch/__init__.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/fetch/__init__.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,271 @@
+import importlib
+from yaml import safe_load
+from charmhelpers.core.host import (
+    lsb_release
+)
+from urlparse import (
+    urlparse,
+    urlunparse,
+)
+import subprocess
+from charmhelpers.core.hookenv import (
+    config,
+    log,
+)
+import apt_pkg
+import os
+
+CLOUD_ARCHIVE = """# Ubuntu Cloud Archive
+deb http://ubuntu-cloud.archive.canonical.com/ubuntu {} main
+"""
+PROPOSED_POCKET = """# Proposed
+deb http://archive.ubuntu.com/ubuntu {}-proposed main universe multiverse restricted
+"""
+CLOUD_ARCHIVE_POCKETS = {
+    # Folsom
+    'folsom': 'precise-updates/folsom',
+    'precise-folsom': 'precise-updates/folsom',
+    'precise-folsom/updates': 'precise-updates/folsom',
+    'precise-updates/folsom': 'precise-updates/folsom',
+    'folsom/proposed': 'precise-proposed/folsom',
+    'precise-folsom/proposed': 'precise-proposed/folsom',
+    'precise-proposed/folsom': 'precise-proposed/folsom',
+    # Grizzly
+    'grizzly': 'precise-updates/grizzly',
+    'precise-grizzly': 'precise-updates/grizzly',
+    'precise-grizzly/updates': 'precise-updates/grizzly',
+    'precise-updates/grizzly': 'precise-updates/grizzly',
+    'grizzly/proposed': 'precise-proposed/grizzly',
+    'precise-grizzly/proposed': 'precise-proposed/grizzly',
+    'precise-proposed/grizzly': 'precise-proposed/grizzly',
+    # Havana
+    'havana': 'precise-updates/havana',
+    'precise-havana': 'precise-updates/havana',
+    'precise-havana/updates': 'precise-updates/havana',
+    'precise-updates/havana': 'precise-updates/havana',
+    'havana/proposed': 'precise-proposed/havana',
+    'precies-havana/proposed': 'precise-proposed/havana',
+    'precise-proposed/havana': 'precise-proposed/havana',
+}
+
+
+def filter_installed_packages(packages):
+    """Returns a list of packages that require installation"""
+    apt_pkg.init()
+    cache = apt_pkg.Cache()
+    _pkgs = []
+    for package in packages:
+        try:
+            p = cache[package]
+            p.current_ver or _pkgs.append(package)
+        except KeyError:
+            log('Package {} has no installation candidate.'.format(package),
+                level='WARNING')
+            _pkgs.append(package)
+    return _pkgs
+
+
+def apt_install(packages, options=None, fatal=False):
+    """Install one or more packages"""
+    if options is None:
+        options = ['--option=Dpkg::Options::=--force-confold']
+
+    cmd = ['apt-get', '--assume-yes']
+    cmd.extend(options)
+    cmd.append('install')
+    if isinstance(packages, basestring):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Installing {} with options: {}".format(packages,
+                                                options))
+    env = os.environ.copy()
+    if 'DEBIAN_FRONTEND' not in env:
+        env['DEBIAN_FRONTEND'] = 'noninteractive'
+
+    if fatal:
+        subprocess.check_call(cmd, env=env)
+    else:
+        subprocess.call(cmd, env=env)
+
+
+def apt_update(fatal=False):
+    """Update local apt cache"""
+    cmd = ['apt-get', 'update']
+    if fatal:
+        subprocess.check_call(cmd)
+    else:
+        subprocess.call(cmd)
+
+
+def apt_purge(packages, fatal=False):
+    """Purge one or more packages"""
+    cmd = ['apt-get', '--assume-yes', 'purge']
+    if isinstance(packages, basestring):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Purging {}".format(packages))
+    if fatal:
+        subprocess.check_call(cmd)
+    else:
+        subprocess.call(cmd)
+
+
+def apt_hold(packages, fatal=False):
+    """Hold one or more packages"""
+    cmd = ['apt-mark', 'hold']
+    if isinstance(packages, basestring):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Holding {}".format(packages))
+    if fatal:
+        subprocess.check_call(cmd)
+    else:
+        subprocess.call(cmd)
+
+
+def add_source(source, key=None):
+    if (source.startswith('ppa:') or
+        source.startswith('http:') or
+        source.startswith('deb ') or
+            source.startswith('cloud-archive:')):
+        subprocess.check_call(['add-apt-repository', '--yes', source])
+    elif source.startswith('cloud:'):
+        apt_install(filter_installed_packages(['ubuntu-cloud-keyring']),
+                    fatal=True)
+        pocket = source.split(':')[-1]
+        if pocket not in CLOUD_ARCHIVE_POCKETS:
+            raise SourceConfigError(
+                'Unsupported cloud: source option %s' %
+                pocket)
+        actual_pocket = CLOUD_ARCHIVE_POCKETS[pocket]
+        with open('/etc/apt/sources.list.d/cloud-archive.list', 'w') as apt:
+            apt.write(CLOUD_ARCHIVE.format(actual_pocket))
+    elif source == 'proposed':
+        release = lsb_release()['DISTRIB_CODENAME']
+        with open('/etc/apt/sources.list.d/proposed.list', 'w') as apt:
+            apt.write(PROPOSED_POCKET.format(release))
+    if key:
+        subprocess.check_call(['apt-key', 'import', key])
+
+
+class SourceConfigError(Exception):
+    pass
+
+
+def configure_sources(update=False,
+                      sources_var='install_sources',
+                      keys_var='install_keys'):
+    """
+    Configure multiple sources from charm configuration
+
+    Example config:
+        install_sources:
+          - "ppa:foo"
+          - "http://example.com/repo precise main"
+        install_keys:
+          - null
+          - "a1b2c3d4"
+
+    Note that 'null' (a.k.a. None) should not be quoted.
+    """
+    sources = safe_load(config(sources_var))
+    keys = config(keys_var)
+    if keys is not None:
+        keys = safe_load(keys)
+    if isinstance(sources, basestring) and (
+            keys is None or isinstance(keys, basestring)):
+        add_source(sources, keys)
+    else:
+        if not len(sources) == len(keys):
+            msg = 'Install sources and keys lists are different lengths'
+            raise SourceConfigError(msg)
+        for src_num in range(len(sources)):
+            add_source(sources[src_num], keys[src_num])
+    if update:
+        apt_update(fatal=True)
+
+# The order of this list is very important. Handlers should be listed in from
+# least- to most-specific URL matching.
+FETCH_HANDLERS = (
+    'charmhelpers.fetch.archiveurl.ArchiveUrlFetchHandler',
+    'charmhelpers.fetch.bzrurl.BzrUrlFetchHandler',
+)
+
+
+class UnhandledSource(Exception):
+    pass
+
+
+def install_remote(source):
+    """
+    Install a file tree from a remote source
+
+    The specified source should be a url of the form:
+        scheme://[host]/path[#[option=value][&...]]
+
+    Schemes supported are based on this modules submodules
+    Options supported are submodule-specific"""
+    # We ONLY check for True here because can_handle may return a string
+    # explaining why it can't handle a given source.
+    handlers = [h for h in plugins() if h.can_handle(source) is True]
+    installed_to = None
+    for handler in handlers:
+        try:
+            installed_to = handler.install(source)
+        except UnhandledSource:
+            pass
+    if not installed_to:
+        raise UnhandledSource("No handler found for source {}".format(source))
+    return installed_to
+
+
+def install_from_config(config_var_name):
+    charm_config = config()
+    source = charm_config[config_var_name]
+    return install_remote(source)
+
+
+class BaseFetchHandler(object):
+
+    """Base class for FetchHandler implementations in fetch plugins"""
+
+    def can_handle(self, source):
+        """Returns True if the source can be handled. Otherwise returns
+        a string explaining why it cannot"""
+        return "Wrong source type"
+
+    def install(self, source):
+        """Try to download and unpack the source. Return the path to the
+        unpacked files or raise UnhandledSource."""
+        raise UnhandledSource("Wrong source type {}".format(source))
+
+    def parse_url(self, url):
+        return urlparse(url)
+
+    def base_url(self, url):
+        """Return url without querystring or fragment"""
+        parts = list(self.parse_url(url))
+        parts[4:] = ['' for i in parts[4:]]
+        return urlunparse(parts)
+
+
+def plugins(fetch_handlers=None):
+    if not fetch_handlers:
+        fetch_handlers = FETCH_HANDLERS
+    plugin_list = []
+    for handler_name in fetch_handlers:
+        package, classname = handler_name.rsplit('.', 1)
+        try:
+            handler_class = getattr(
+                importlib.import_module(package),
+                classname)
+            plugin_list.append(handler_class())
+        except (ImportError, AttributeError):
+            # Skip missing plugins so that they can be ommitted from
+            # installation if desired
+            log("FetchHandler {} not found, skipping plugin".format(
+                handler_name))
+    return plugin_list
 
=== added file 'lib/charmhelpers/fetch/archiveurl.py'
--- lib/charmhelpers/fetch/archiveurl.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/fetch/archiveurl.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,48 @@
+import os
+import urllib2
+from charmhelpers.fetch import (
+    BaseFetchHandler,
+    UnhandledSource
+)
+from charmhelpers.payload.archive import (
+    get_archive_handler,
+    extract,
+)
+from charmhelpers.core.host import mkdir
+
+
+class ArchiveUrlFetchHandler(BaseFetchHandler):
+    """Handler for archives via generic URLs"""
+    def can_handle(self, source):
+        url_parts = self.parse_url(source)
+        if url_parts.scheme not in ('http', 'https', 'ftp', 'file'):
+            return "Wrong source type"
+        if get_archive_handler(self.base_url(source)):
+            return True
+        return False
+
+    def download(self, source, dest):
+        # propogate all exceptions
+        # URLError, OSError, etc
+        response = urllib2.urlopen(source)
+        try:
+            with open(dest, 'w') as dest_file:
+                dest_file.write(response.read())
+        except Exception as e:
+            if os.path.isfile(dest):
+                os.unlink(dest)
+            raise e
+
+    def install(self, source):
+        url_parts = self.parse_url(source)
+        dest_dir = os.path.join(os.environ.get('CHARM_DIR'), 'fetched')
+        if not os.path.exists(dest_dir):
+            mkdir(dest_dir, perms=0755)
+        dld_file = os.path.join(dest_dir, os.path.basename(url_parts.path))
+        try:
+            self.download(source, dld_file)
+        except urllib2.URLError as e:
+            raise UnhandledSource(e.reason)
+        except OSError as e:
+            raise UnhandledSource(e.strerror)
+        return extract(dld_file)
 
=== added file 'lib/charmhelpers/fetch/bzrurl.py'
--- lib/charmhelpers/fetch/bzrurl.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/fetch/bzrurl.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,49 @@
+import os
+from charmhelpers.fetch import (
+    BaseFetchHandler,
+    UnhandledSource
+)
+from charmhelpers.core.host import mkdir
+
+try:
+    from bzrlib.branch import Branch
+except ImportError:
+    from charmhelpers.fetch import apt_install
+    apt_install("python-bzrlib")
+    from bzrlib.branch import Branch
+
+
+class BzrUrlFetchHandler(BaseFetchHandler):
+    """Handler for bazaar branches via generic and lp URLs"""
+    def can_handle(self, source):
+        url_parts = self.parse_url(source)
+        if url_parts.scheme not in ('bzr+ssh', 'lp'):
+            return False
+        else:
+            return True
+
+    def branch(self, source, dest):
+        url_parts = self.parse_url(source)
+        # If we use lp:branchname scheme we need to load plugins
+        if not self.can_handle(source):
+            raise UnhandledSource("Cannot handle {}".format(source))
+        if url_parts.scheme == "lp":
+            from bzrlib.plugin import load_plugins
+            load_plugins()
+        try:
+            remote_branch = Branch.open(source)
+            remote_branch.bzrdir.sprout(dest).open_branch()
+        except Exception as e:
+            raise e
+
+    def install(self, source):
+        url_parts = self.parse_url(source)
+        branch_name = url_parts.path.strip("/").split("/")[-1]
+        dest_dir = os.path.join(os.environ.get('CHARM_DIR'), "fetched", branch_name)
+        if not os.path.exists(dest_dir):
+            mkdir(dest_dir, perms=0755)
+        try:
+            self.branch(source, dest_dir)
+        except OSError as e:
+            raise UnhandledSource(e.strerror)
+        return dest_dir
 
=== added directory 'lib/charmhelpers/payload'
=== added file 'lib/charmhelpers/payload/__init__.py'
--- lib/charmhelpers/payload/__init__.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/payload/__init__.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,1 @@
+"Tools for working with files injected into a charm just before deployment."
 
=== added file 'lib/charmhelpers/payload/archive.py'
--- lib/charmhelpers/payload/archive.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/payload/archive.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,57 @@
+import os
+import tarfile
+import zipfile
+from charmhelpers.core import (
+    host,
+    hookenv,
+)
+
+
+class ArchiveError(Exception):
+    pass
+
+
+def get_archive_handler(archive_name):
+    if os.path.isfile(archive_name):
+        if tarfile.is_tarfile(archive_name):
+            return extract_tarfile
+        elif zipfile.is_zipfile(archive_name):
+            return extract_zipfile
+    else:
+        # look at the file name
+        for ext in ('.tar', '.tar.gz', '.tgz', 'tar.bz2', '.tbz2', '.tbz'):
+            if archive_name.endswith(ext):
+                return extract_tarfile
+        for ext in ('.zip', '.jar'):
+            if archive_name.endswith(ext):
+                return extract_zipfile
+
+
+def archive_dest_default(archive_name):
+    archive_file = os.path.basename(archive_name)
+    return os.path.join(hookenv.charm_dir(), "archives", archive_file)
+
+
+def extract(archive_name, destpath=None):
+    handler = get_archive_handler(archive_name)
+    if handler:
+        if not destpath:
+            destpath = archive_dest_default(archive_name)
+        if not os.path.isdir(destpath):
+            host.mkdir(destpath)
+        handler(archive_name, destpath)
+        return destpath
+    else:
+        raise ArchiveError("No handler for archive")
+
+
+def extract_tarfile(archive_name, destpath):
+    "Unpack a tar archive, optionally compressed"
+    archive = tarfile.open(archive_name)
+    archive.extractall(destpath)
+
+
+def extract_zipfile(archive_name, destpath):
+    "Unpack a zip file"
+    archive = zipfile.ZipFile(archive_name)
+    archive.extractall(destpath)
 
=== added file 'lib/charmhelpers/payload/execd.py'
--- lib/charmhelpers/payload/execd.py	1970-01-01 00:00:00 +0000
+++ lib/charmhelpers/payload/execd.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+
+import os
+import sys
+import subprocess
+from charmhelpers.core import hookenv
+
+
+def default_execd_dir():
+    return os.path.join(os.environ['CHARM_DIR'], 'exec.d')
+
+
+def execd_module_paths(execd_dir=None):
+    """Generate a list of full paths to modules within execd_dir."""
+    if not execd_dir:
+        execd_dir = default_execd_dir()
+
+    if not os.path.exists(execd_dir):
+        return
+
+    for subpath in os.listdir(execd_dir):
+        module = os.path.join(execd_dir, subpath)
+        if os.path.isdir(module):
+            yield module
+
+
+def execd_submodule_paths(command, execd_dir=None):
+    """Generate a list of full paths to the specified command within exec_dir.
+    """
+    for module_path in execd_module_paths(execd_dir):
+        path = os.path.join(module_path, command)
+        if os.access(path, os.X_OK) and os.path.isfile(path):
+            yield path
+
+
+def execd_run(command, execd_dir=None, die_on_error=False, stderr=None):
+    """Run command for each module within execd_dir which defines it."""
+    for submodule_path in execd_submodule_paths(command, execd_dir):
+        try:
+            subprocess.check_call(submodule_path, shell=True, stderr=stderr)
+        except subprocess.CalledProcessError as e:
+            hookenv.log("Error ({}) running  {}. Output: {}".format(
+                e.returncode, e.cmd, e.output))
+            if die_on_error:
+                sys.exit(e.returncode)
+
+
+def execd_preinstall(execd_dir=None):
+    """Run charm-pre-install for each module within execd_dir."""
+    execd_run('charm-pre-install', execd_dir=execd_dir)
 
=== modified file 'metadata.yaml'
--- metadata.yaml	2013-05-20 13:19:13 +0000
+++ metadata.yaml	2013-11-21 22:43:22 +0000
@@ -9,10 +9,10 @@
 provides:
   amqp:
     interface: rabbitmq
-requires:
   nrpe-external-master:
     interface: nrpe-external-master
     scope: container
+requires:
   ha:
     interface: hacluster
     scope: container
 
=== modified file 'revision'
--- revision	2013-08-08 21:22:39 +0000
+++ revision	2013-11-21 22:43:22 +0000
@@ -1,1 +1,1 @@
-97
+98
 
=== added file 'scripts/check_rabbitmq.py'
--- scripts/check_rabbitmq.py	1970-01-01 00:00:00 +0000
+++ scripts/check_rabbitmq.py	2013-11-21 22:43:22 +0000
@@ -0,0 +1,237 @@
+#!/usr/bin/python
+#
+#       #
+#       #  #    #       #  #    #
+#       #  #    #       #  #    #
+#       #  #    #       #  #    #
+# #     #  #    #       #  #    #
+# #     #  #    #  #    #  #    #
+#  #####    ####    ####    ####
+
+# This file is managed by juju.  Do not make local changes.
+
+# Copyright (C) 2009, 2012 Canonical
+# All Rights Reserved
+#
+# tests RabbitMQ operation
+
+""" test rabbitmq functionality """
+
+import os
+import sys
+import signal
+import socket
+
+try:
+    from amqplib import client_0_8 as amqp
+except ImportError:
+    print "CRITICAL: amqplib not found"
+    sys.exit(2)
+
+from optparse import OptionParser
+
+ROUTE_KEY = "test_mq"
+
+
+def alarm_handler(signum, frame):
+    print "TIMEOUT waiting for all queued messages to be delivered"
+    os._exit(1)
+
+
+def get_connection(host_port, user, password, vhost):
+    """ connect to the amqp service """
+    if options.verbose:
+        print "Connection to %s requested" % host_port
+    try:
+        ret = amqp.Connection(host=host_port, userid=user,
+                              password=password, virtual_host=vhost,
+                              insist=False)
+    except (socket.error, TypeError), e:
+        print "ERROR: Could not connect to RabbitMQ server %s:%d" % (
+            options.host, options.port)
+        if options.verbose:
+            print e
+            raise
+        sys.exit(2)
+    except:
+        print "ERROR: Unknown error connecting to RabbitMQ server %s:%d" % (
+            options.host, options.port)
+        if options.verbose:
+            raise
+        sys.exit(3)
+    return ret
+
+
+def setup_exchange(conn, exchange_name, exchange_type):
+    """ create an exchange """
+    # see if we already have the exchange
+    must_create = False
+    chan = conn.channel()
+    try:
+        chan.exchange_declare(exchange=exchange_name, type=exchange_type,
+                              passive=True)
+    except (amqp.AMQPConnectionException, amqp.AMQPChannelException), e:
+        if e.amqp_reply_code == 404:
+            must_create = True
+            # amqplib kills the channel on error.... we dispose of it too
+            chan.close()
+            chan = conn.channel()
+        else:
+            raise
+    # now create the exchange if needed
+    if must_create:
+        chan.exchange_declare(exchange=exchange_name, type=exchange_type,
+                              durable=False, auto_delete=False,)
+        if options.verbose:
+            print "Created new exchange %s (%s)" % (
+                exchange_name, exchange_type)
+    else:
+        if options.verbose:
+            print "Exchange %s (%s) is already declared" % (
+                exchange_name, exchange_type)
+    chan.close()
+    return must_create
+
+
+class Consumer(object):
+    """ message consumer class """
+    _quit = False
+
+    def __init__(self, conn, exname):
+        self.exname = exname
+        self.connection = conn
+        self.name = "%s_queue" % exname
+
+    def setup(self):
+        """ sets up the queue and links it to the exchange """
+        if options.verbose:
+            print self.name, "setup"
+        chan = self.connection.channel()
+        # setup the queue
+        chan.queue_declare(queue=self.name, durable=False,
+                           exclusive=False, auto_delete=False)
+        chan.queue_bind(queue=self.name, exchange=self.exname,
+                        routing_key=ROUTE_KEY)
+        chan.queue_purge(self.name)
+        chan.close()
+
+    def check_end(self, msg):
+        """ checks if this is an end request """
+        return msg.body.startswith("QUIT")
+
+    def loop(self, timeout=5):
+        """ main loop for the consumer client """
+        consumer_tag = "callback_%s" % self.name
+        chan = self.connection.channel()
+
+        def callback(msg):
+            """ callback for message received """
+            if options.verbose:
+                print "Client %s saw this message: '%s'" % (self.name, msg.body)
+            if self.check_end(msg):  # we have been asked to quit
+                self._quit = True
+        chan.basic_consume(queue=self.name, no_ack=True, callback=callback,
+                           consumer_tag=consumer_tag)
+        signal.signal(signal.SIGALRM, alarm_handler)
+        signal.alarm(timeout)
+        while True:
+            chan.wait()
+            if self._quit:
+                break
+        # cancel alarm for receive wait
+        signal.alarm(0)
+        chan.basic_cancel(consumer_tag)
+        chan.close()
+        return self._quit
+
+
+def send_message(chan, exname, counter=None, message=None):
+    """ publish a message on the exchange """
+    if not message:
+        message = "This is test message %d" % counter
+    msg = amqp.Message(message)
+    chan.basic_publish(msg, exchange=exname, routing_key=ROUTE_KEY)
+    if options.verbose:
+        print "Sent message: %s" % message
+
+
+def main_loop(conn, exname):
+    """ demo code to send/receive a few messages """
+    # first, set up a few consumers
+    # setup the queue that would collect the messages
+    consumer = Consumer(conn, exname)
+    consumer.setup()
+    # open up our own connection and start sending messages
+    chan = conn.channel()
+    # loop a few messages
+    for i in range(options.messages):
+        send_message(chan, exname, i)
+    # signal end of test
+    send_message(chan, exname, message="QUIT")
+    chan.close()
+
+    # loop around for a while waiting for messages to be picked up
+    return consumer.loop(timeout=options.timeout)
+
+
+def main(host, port, exname, extype, user, password, vhost):
+    """ setup the connection and the communication channel """
+    sys.stdout = os.fdopen(os.dup(1), "w", 0)
+    host_port = "%s:%s" % (host, port)
+    conn = get_connection(host_port, user, password, vhost)
+    chan = conn.channel()
+    if setup_exchange(conn, exname, extype):
+        if options.verbose:
+            print "Created %s exchange of type %s" % (exname, extype)
+    else:
+        if options.verbose:
+            print "Reusing existing exchange %s of type %s" % (exname, extype)
+    ret = main_loop(conn, exname)
+    chan.close()
+    conn.close()
+    return ret
+
+if __name__ == '__main__':
+    parser = OptionParser()
+    parser.add_option("--host", dest="host",
+                      help="RabbitMQ host [default=%default]",
+                      metavar="HOST", default="localhost")
+    parser.add_option("--port", dest="port", type="int",
+                      help="port RabbitMQ is running on [default=%default]",
+                      metavar="PORT", default=5672)
+    parser.add_option("--exchange", dest="exchange",
+                      help="Exchange name to use [default=%default]",
+                      default="test_exchange", metavar="EXCHANGE")
+    parser.add_option("--type", dest="type",
+                      help="EXCHANGE type [default=%default]",
+                      metavar="TYPE", default="fanout")
+    parser.add_option("-v", "--verbose", default=False, action="store_true",
+                      help="verbose run")
+    parser.add_option("-m", "--messages", dest="messages", type="int",
+                      help="send NUM messages for testing [default=%default]",
+                      metavar="NUM", default=10)
+    parser.add_option("-t", "--timeout", dest="timeout", type="int",
+                      help="wait TIMEOUT sec for loop test [default=%default]",
+                      metavar="TIMEOUT", default=5)
+    parser.add_option("-u", "--user", dest="user", default="guest",
+                      help="RabbitMQ user [default=%default]",
+                      metavar="USER")
+    parser.add_option("-p", "--password", dest="password", default="guest",
+                      help="RabbitMQ password [default=%default]",
+                      metavar="PASSWORD")
+    parser.add_option("--vhost", dest="vhost", default="/",
+                      help="RabbitMQ vhost [default=%default]",
+                      metavar="VHOST")
+
+    (options, args) = parser.parse_args()
+    if options.verbose:
+        print """
+Using AMQP setup: host:port=%s:%d exchange_name=%s exchange_type=%s
+""" % (options.host, options.port, options.exchange, options.type)
+    ret = main(options.host, options.port, options.exchange, options.type,
+               options.user, options.password, options.vhost)
+    if ret:
+        print "Ok: sent and received %d test messages" % options.messages
+        sys.exit(0)
+    print "ERROR: Could not send/receive test messages"
+    sys.exit(3)