Merge lp:~gnuoy/charms/trusty/ceilometer-agent/stable-charm-sync into lp:~openstack-charmers-archive/charms/trusty/ceilometer-agent/trunk

[Liam Young]

[lp:~gnuoy/charms/trusty/ceilometer-agent/stable-charm-sync]

40. By Liam Young on 2014-08-27

Resync charmhelpers for cache bug fixes

[Chris Glass (tribaal)]

Looks good! +1

review: Approve

=== added file '.bzrignore'
--- .bzrignore	1970-01-01 00:00:00 +0000
+++ .bzrignore	2014-08-27 07:08:22 +0000
@@ -0,0 +1,2 @@
+bin
+.coverage

=== modified file 'Makefile'
--- Makefile	2013-10-14 16:10:30 +0000
+++ Makefile	2014-08-27 07:08:22 +0000
@@ -1,11 +1,17 @@
 #!/usr/bin/make
+PYTHON := /usr/bin/env python
 
 lint:
 	@flake8 --exclude hooks/charmhelpers hooks
 	@charm proof
 
-sync:
-	@charm-helper-sync -c charm-helpers.yaml
+bin/charm_helpers_sync.py:
+	@mkdir -p bin
+	@bzr cat lp:charm-helpers/tools/charm_helpers_sync/charm_helpers_sync.py \
+	> bin/charm_helpers_sync.py
+
+sync: bin/charm_helpers_sync.py
+	@$(PYTHON) bin/charm_helpers_sync.py -c charm-helpers.yaml
 
 test:
 	@$(PYTHON) /usr/bin/nosetests --nologcapture --with-coverage  unit_tests

=== modified file 'charm-helpers.yaml'
--- charm-helpers.yaml	2014-03-25 17:03:52 +0000
+++ charm-helpers.yaml	2014-08-27 07:08:22 +0000
@@ -1,4 +1,4 @@
-branch: lp:charm-helpers
+branch: lp:~openstack-charmers/charm-helpers/stable
 destination: hooks/charmhelpers
 include:
     - core

=== modified file 'hooks/charmhelpers/contrib/openstack/context.py'
--- hooks/charmhelpers/contrib/openstack/context.py	2014-04-10 15:36:48 +0000
+++ hooks/charmhelpers/contrib/openstack/context.py	2014-08-27 07:08:22 +0000
@@ -24,6 +24,7 @@
     unit_get,
     unit_private_ip,
     ERROR,
+    INFO
 )
 
 from charmhelpers.contrib.hahelpers.cluster import (
@@ -570,7 +571,7 @@
 
         if self.plugin == 'ovs':
             ctxt.update(self.ovs_ctxt())
-        elif self.plugin == 'nvp':
+        elif self.plugin in ['nvp', 'nsx']:
             ctxt.update(self.nvp_ctxt())
 
         alchemy_flags = config('neutron-alchemy-flags')
@@ -657,7 +658,7 @@
         self.interface = interface
 
     def __call__(self):
-        ctxt = {}
+        ctxt = {'sections': {}}
         for rid in relation_ids(self.interface):
             for unit in related_units(rid):
                 sub_config = relation_get('subordinate_configuration',
@@ -683,10 +684,14 @@
 
                     sub_config = sub_config[self.config_file]
                     for k, v in sub_config.iteritems():
-                        ctxt[k] = v
+                        if k == 'sections':
+                            for section, config_dict in v.iteritems():
+                                log("adding section '%s'" % (section))
+                                ctxt[k][section] = config_dict
+                        else:
+                            ctxt[k] = v
 
-        if not ctxt:
-            ctxt['sections'] = {}
+        log("%d section(s) found" % (len(ctxt['sections'])), level=INFO)
 
         return ctxt
 

=== modified file 'hooks/charmhelpers/contrib/openstack/neutron.py'
--- hooks/charmhelpers/contrib/openstack/neutron.py	2014-03-27 10:19:40 +0000
+++ hooks/charmhelpers/contrib/openstack/neutron.py	2014-08-27 07:08:22 +0000
@@ -114,14 +114,30 @@
             'server_packages': ['neutron-server',
                                 'neutron-plugin-nicira'],
             'server_services': ['neutron-server']
+        },
+        'nsx': {
+            'config': '/etc/neutron/plugins/vmware/nsx.ini',
+            'driver': 'vmware',
+            'contexts': [
+                context.SharedDBContext(user=config('neutron-database-user'),
+                                        database=config('neutron-database'),
+                                        relation_prefix='neutron',
+                                        ssl_dir=NEUTRON_CONF_DIR)],
+            'services': [],
+            'packages': [],
+            'server_packages': ['neutron-server',
+                                'neutron-plugin-vmware'],
+            'server_services': ['neutron-server']
         }
     }
-    # NOTE: patch in ml2 plugin for icehouse onwards
     if release >= 'icehouse':
+        # NOTE: patch in ml2 plugin for icehouse onwards
         plugins['ovs']['config'] = '/etc/neutron/plugins/ml2/ml2_conf.ini'
         plugins['ovs']['driver'] = 'neutron.plugins.ml2.plugin.Ml2Plugin'
         plugins['ovs']['server_packages'] = ['neutron-server',
                                              'neutron-plugin-ml2']
+        # NOTE: patch in vmware renames nvp->nsx for icehouse onwards
+        plugins['nvp'] = plugins['nsx']
     return plugins
 
 

=== modified file 'hooks/charmhelpers/contrib/openstack/utils.py'
--- hooks/charmhelpers/contrib/openstack/utils.py	2014-04-10 15:36:48 +0000
+++ hooks/charmhelpers/contrib/openstack/utils.py	2014-08-27 07:08:22 +0000
@@ -24,7 +24,7 @@
 )
 
 from charmhelpers.core.host import lsb_release, mounts, umount
-from charmhelpers.fetch import apt_install
+from charmhelpers.fetch import apt_install, apt_cache
 from charmhelpers.contrib.storage.linux.utils import is_block_device, zap_disk
 from charmhelpers.contrib.storage.linux.loopback import ensure_loopback_device
 
@@ -130,8 +130,8 @@
 
 def get_os_codename_package(package, fatal=True):
     '''Derive OpenStack release codename from an installed package.'''
-    apt.init()
-    cache = apt.Cache()
+
+    cache = apt_cache()
 
     try:
         pkg = cache[package]
@@ -183,7 +183,7 @@
         if cname == codename:
             return version
     #e = "Could not determine OpenStack version for package: %s" % pkg
-    #error_out(e)
+    # error_out(e)
 
 
 os_rel = None
@@ -401,6 +401,8 @@
         rtype = 'PTR'
     elif isinstance(address, basestring):
         rtype = 'A'
+    else:
+        return None
 
     answers = dns.resolver.query(address, rtype)
     if answers:

=== modified file 'hooks/charmhelpers/contrib/storage/linux/lvm.py'
--- hooks/charmhelpers/contrib/storage/linux/lvm.py	2013-11-06 01:23:03 +0000
+++ hooks/charmhelpers/contrib/storage/linux/lvm.py	2014-08-27 07:08:22 +0000
@@ -62,7 +62,7 @@
     pvd = check_output(['pvdisplay', block_device]).splitlines()
     for l in pvd:
         if l.strip().startswith('VG Name'):
-            vg = ' '.join(l.split()).split(' ').pop()
+            vg = ' '.join(l.strip().split()[2:])
     return vg
 
 

=== modified file 'hooks/charmhelpers/contrib/storage/linux/utils.py'
--- hooks/charmhelpers/contrib/storage/linux/utils.py	2014-03-20 13:38:40 +0000
+++ hooks/charmhelpers/contrib/storage/linux/utils.py	2014-08-27 07:08:22 +0000
@@ -1,8 +1,11 @@
-from os import stat
+import os
+import re
 from stat import S_ISBLK
 
 from subprocess import (
-    check_call
+    check_call,
+    check_output,
+    call
 )
 
 
@@ -12,7 +15,9 @@
 
     :returns: boolean: True if path is a block device, False if not.
     '''
-    return S_ISBLK(stat(path).st_mode)
+    if not os.path.exists(path):
+        return False
+    return S_ISBLK(os.stat(path).st_mode)
 
 
 def zap_disk(block_device):
@@ -22,5 +27,27 @@
 
     :param block_device: str: Full path of block device to clean.
     '''
-    check_call(['sgdisk', '--zap-all', '--clear',
-                '--mbrtogpt', block_device])
+    # sometimes sgdisk exits non-zero; this is OK, dd will clean up
+    call(['sgdisk', '--zap-all', '--mbrtogpt',
+          '--clear', block_device])
+    dev_end = check_output(['blockdev', '--getsz', block_device])
+    gpt_end = int(dev_end.split()[0]) - 100
+    check_call(['dd', 'if=/dev/zero', 'of=%s' % (block_device),
+                'bs=1M', 'count=1'])
+    check_call(['dd', 'if=/dev/zero', 'of=%s' % (block_device),
+                'bs=512', 'count=100', 'seek=%s' % (gpt_end)])
+
+
+def is_device_mounted(device):
+    '''Given a device path, return True if that device is mounted, and False
+    if it isn't.
+
+    :param device: str: Full path of the device to check.
+    :returns: boolean: True if the path represents a mounted device, False if
+        it doesn't.
+    '''
+    is_partition = bool(re.search(r".*[0-9]+\b", device))
+    out = check_output(['mount'])
+    if is_partition:
+        return bool(re.search(device + r"\b", out))
+    return bool(re.search(device + r"[0-9]+\b", out))

=== added file 'hooks/charmhelpers/core/fstab.py'
--- hooks/charmhelpers/core/fstab.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/fstab.py	2014-08-27 07:08:22 +0000
@@ -0,0 +1,116 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+__author__ = 'Jorge Niedbalski R. <[e-mail]>'
+
+import os
+
+
+class Fstab(file):
+    """This class extends file in order to implement a file reader/writer
+    for file `/etc/fstab`
+    """
+
+    class Entry(object):
+        """Entry class represents a non-comment line on the `/etc/fstab` file
+        """
+        def __init__(self, device, mountpoint, filesystem,
+                     options, d=0, p=0):
+            self.device = device
+            self.mountpoint = mountpoint
+            self.filesystem = filesystem
+
+            if not options:
+                options = "defaults"
+
+            self.options = options
+            self.d = d
+            self.p = p
+
+        def __eq__(self, o):
+            return str(self) == str(o)
+
+        def __str__(self):
+            return "{} {} {} {} {} {}".format(self.device,
+                                              self.mountpoint,
+                                              self.filesystem,
+                                              self.options,
+                                              self.d,
+                                              self.p)
+
+    DEFAULT_PATH = os.path.join(os.path.sep, 'etc', 'fstab')
+
+    def __init__(self, path=None):
+        if path:
+            self._path = path
+        else:
+            self._path = self.DEFAULT_PATH
+        file.__init__(self, self._path, 'r+')
+
+    def _hydrate_entry(self, line):
+        # NOTE: use split with no arguments to split on any
+        #       whitespace including tabs
+        return Fstab.Entry(*filter(
+            lambda x: x not in ('', None),
+            line.strip("\n").split()))
+
+    @property
+    def entries(self):
+        self.seek(0)
+        for line in self.readlines():
+            try:
+                if not line.startswith("#"):
+                    yield self._hydrate_entry(line)
+            except ValueError:
+                pass
+
+    def get_entry_by_attr(self, attr, value):
+        for entry in self.entries:
+            e_attr = getattr(entry, attr)
+            if e_attr == value:
+                return entry
+        return None
+
+    def add_entry(self, entry):
+        if self.get_entry_by_attr('device', entry.device):
+            return False
+
+        self.write(str(entry) + '\n')
+        self.truncate()
+        return entry
+
+    def remove_entry(self, entry):
+        self.seek(0)
+
+        lines = self.readlines()
+
+        found = False
+        for index, line in enumerate(lines):
+            if not line.startswith("#"):
+                if self._hydrate_entry(line) == entry:
+                    found = True
+                    break
+
+        if not found:
+            return False
+
+        lines.remove(line)
+
+        self.seek(0)
+        self.write(''.join(lines))
+        self.truncate()
+        return True
+
+    @classmethod
+    def remove_by_mountpoint(cls, mountpoint, path=None):
+        fstab = cls(path=path)
+        entry = fstab.get_entry_by_attr('mountpoint', mountpoint)
+        if entry:
+            return fstab.remove_entry(entry)
+        return False
+
+    @classmethod
+    def add(cls, device, mountpoint, filesystem, options=None, path=None):
+        return cls(path=path).add_entry(Fstab.Entry(device,
+                                                    mountpoint, filesystem,
+                                                    options=options))

=== modified file 'hooks/charmhelpers/core/hookenv.py'
--- hooks/charmhelpers/core/hookenv.py	2014-03-20 13:38:40 +0000
+++ hooks/charmhelpers/core/hookenv.py	2014-08-27 07:08:22 +0000
@@ -155,6 +155,100 @@
     return os.path.basename(sys.argv[0])
 
 
+class Config(dict):
+    """A Juju charm config dictionary that can write itself to
+    disk (as json) and track which values have changed since
+    the previous hook invocation.
+
+    Do not instantiate this object directly - instead call
+    ``hookenv.config()``
+
+    Example usage::
+
+        >>> # inside a hook
+        >>> from charmhelpers.core import hookenv
+        >>> config = hookenv.config()
+        >>> config['foo']
+        'bar'
+        >>> config['mykey'] = 'myval'
+        >>> config.save()
+
+
+        >>> # user runs `juju set mycharm foo=baz`
+        >>> # now we're inside subsequent config-changed hook
+        >>> config = hookenv.config()
+        >>> config['foo']
+        'baz'
+        >>> # test to see if this val has changed since last hook
+        >>> config.changed('foo')
+        True
+        >>> # what was the previous value?
+        >>> config.previous('foo')
+        'bar'
+        >>> # keys/values that we add are preserved across hooks
+        >>> config['mykey']
+        'myval'
+        >>> # don't forget to save at the end of hook!
+        >>> config.save()
+
+    """
+    CONFIG_FILE_NAME = '.juju-persistent-config'
+
+    def __init__(self, *args, **kw):
+        super(Config, self).__init__(*args, **kw)
+        self._prev_dict = None
+        self.path = os.path.join(charm_dir(), Config.CONFIG_FILE_NAME)
+        if os.path.exists(self.path):
+            self.load_previous()
+
+    def load_previous(self, path=None):
+        """Load previous copy of config from disk so that current values
+        can be compared to previous values.
+
+        :param path:
+
+            File path from which to load the previous config. If `None`,
+            config is loaded from the default location. If `path` is
+            specified, subsequent `save()` calls will write to the same
+            path.
+
+        """
+        self.path = path or self.path
+        with open(self.path) as f:
+            self._prev_dict = json.load(f)
+
+    def changed(self, key):
+        """Return true if the value for this key has changed since
+        the last save.
+
+        """
+        if self._prev_dict is None:
+            return True
+        return self.previous(key) != self.get(key)
+
+    def previous(self, key):
+        """Return previous value for this key, or None if there
+        is no "previous" value.
+
+        """
+        if self._prev_dict:
+            return self._prev_dict.get(key)
+        return None
+
+    def save(self):
+        """Save this config to disk.
+
+        Preserves items in _prev_dict that do not exist in self.
+
+        """
+        if self._prev_dict:
+            for k, v in self._prev_dict.iteritems():
+                if k not in self:
+                    self[k] = v
+        with open(self.path, 'w') as f:
+            json.dump(self, f)
+
+
 @cached
 def config(scope=None):
     """Juju charm configuration"""
@@ -163,7 +257,10 @@
         config_cmd_line.append(scope)
     config_cmd_line.append('--format=json')
     try:
-        return json.loads(subprocess.check_output(config_cmd_line))
+        config_data = json.loads(subprocess.check_output(config_cmd_line))
+        if scope is not None:
+            return config_data
+        return Config(config_data)
     except ValueError:
         return None
 

=== modified file 'hooks/charmhelpers/core/host.py'
--- hooks/charmhelpers/core/host.py	2014-03-20 13:38:40 +0000
+++ hooks/charmhelpers/core/host.py	2014-08-27 07:08:22 +0000
@@ -12,10 +12,12 @@
 import string
 import subprocess
 import hashlib
+import apt_pkg
 
 from collections import OrderedDict
 
 from hookenv import log
+from fstab import Fstab
 
 
 def service_start(service_name):
@@ -34,7 +36,8 @@
 
 
 def service_reload(service_name, restart_on_failure=False):
-    """Reload a system service, optionally falling back to restart if reload fails"""
+    """Reload a system service, optionally falling back to restart if
+    reload fails"""
     service_result = service('reload', service_name)
     if not service_result and restart_on_failure:
         service_result = service('restart', service_name)
@@ -143,7 +146,19 @@
         target.write(content)
 
 
-def mount(device, mountpoint, options=None, persist=False):
+def fstab_remove(mp):
+    """Remove the given mountpoint entry from /etc/fstab
+    """
+    return Fstab.remove_by_mountpoint(mp)
+
+
+def fstab_add(dev, mp, fs, options=None):
+    """Adds the given device entry to the /etc/fstab file
+    """
+    return Fstab.add(dev, mp, fs, options=options)
+
+
+def mount(device, mountpoint, options=None, persist=False, filesystem="ext3"):
     """Mount a filesystem at a particular mountpoint"""
     cmd_args = ['mount']
     if options is not None:
@@ -154,9 +169,9 @@
     except subprocess.CalledProcessError, e:
         log('Error mounting {} at {}\n{}'.format(device, mountpoint, e.output))
         return False
+
     if persist:
-        # TODO: update fstab
-        pass
+        return fstab_add(device, mountpoint, filesystem, options=options)
     return True
 
 
@@ -168,9 +183,9 @@
     except subprocess.CalledProcessError, e:
         log('Error unmounting {}\n{}'.format(mountpoint, e.output))
         return False
+
     if persist:
-        # TODO: update fstab
-        pass
+        return fstab_remove(mountpoint)
     return True
 
 
@@ -295,3 +310,16 @@
     if 'link/ether' in words:
         hwaddr = words[words.index('link/ether') + 1]
     return hwaddr
+
+
+def cmp_pkgrevno(package, revno, pkgcache=None):
+    '''Compare supplied revno with the revno of the installed package
+       1 => Installed revno is greater than supplied arg
+       0 => Installed revno is the same as supplied arg
+      -1 => Installed revno is less than supplied arg
+    '''
+    from charmhelpers.fetch import apt_cache
+    if not pkgcache:
+        pkgcache = apt_cache()
+    pkg = pkgcache[package]
+    return apt_pkg.version_compare(pkg.current_ver.ver_str, revno)

=== modified file 'hooks/charmhelpers/fetch/__init__.py'
--- hooks/charmhelpers/fetch/__init__.py	2014-03-20 13:40:24 +0000
+++ hooks/charmhelpers/fetch/__init__.py	2014-08-27 07:08:22 +0000
@@ -1,4 +1,5 @@
 import importlib
+import time
 from yaml import safe_load
 from charmhelpers.core.host import (
     lsb_release
@@ -15,6 +16,7 @@
 import apt_pkg
 import os
 
+
 CLOUD_ARCHIVE = """# Ubuntu Cloud Archive
 deb http://ubuntu-cloud.archive.canonical.com/ubuntu {} main
 """
@@ -56,11 +58,58 @@
     'precise-proposed/icehouse': 'precise-proposed/icehouse',
 }
 
+# The order of this list is very important. Handlers should be listed in from
+# least- to most-specific URL matching.
+FETCH_HANDLERS = (
+    'charmhelpers.fetch.archiveurl.ArchiveUrlFetchHandler',
+    'charmhelpers.fetch.bzrurl.BzrUrlFetchHandler',
+)
+
+APT_NO_LOCK = 100  # The return code for "couldn't acquire lock" in APT.
+APT_NO_LOCK_RETRY_DELAY = 10  # Wait 10 seconds between apt lock checks.
+APT_NO_LOCK_RETRY_COUNT = 30  # Retry to acquire the lock X times.
+
+
+class SourceConfigError(Exception):
+    pass
+
+
+class UnhandledSource(Exception):
+    pass
+
+
+class AptLockError(Exception):
+    pass
+
+
+class BaseFetchHandler(object):
+
+    """Base class for FetchHandler implementations in fetch plugins"""
+
+    def can_handle(self, source):
+        """Returns True if the source can be handled. Otherwise returns
+        a string explaining why it cannot"""
+        return "Wrong source type"
+
+    def install(self, source):
+        """Try to download and unpack the source. Return the path to the
+        unpacked files or raise UnhandledSource."""
+        raise UnhandledSource("Wrong source type {}".format(source))
+
+    def parse_url(self, url):
+        return urlparse(url)
+
+    def base_url(self, url):
+        """Return url without querystring or fragment"""
+        parts = list(self.parse_url(url))
+        parts[4:] = ['' for i in parts[4:]]
+        return urlunparse(parts)
+
 
 def filter_installed_packages(packages):
     """Returns a list of packages that require installation"""
-    apt_pkg.init()
-    cache = apt_pkg.Cache()
+
+    cache = apt_cache()
     _pkgs = []
     for package in packages:
         try:
@@ -73,6 +122,15 @@
     return _pkgs
 
 
+def apt_cache(in_memory=True):
+    """Build and return an apt cache"""
+    apt_pkg.init()
+    if in_memory:
+        apt_pkg.config.set("Dir::Cache::pkgcache", "")
+        apt_pkg.config.set("Dir::Cache::srcpkgcache", "")
+    return apt_pkg.Cache()
+
+
 def apt_install(packages, options=None, fatal=False):
     """Install one or more packages"""
     if options is None:
@@ -87,14 +145,7 @@
         cmd.extend(packages)
     log("Installing {} with options: {}".format(packages,
                                                 options))
-    env = os.environ.copy()
-    if 'DEBIAN_FRONTEND' not in env:
-        env['DEBIAN_FRONTEND'] = 'noninteractive'
-
-    if fatal:
-        subprocess.check_call(cmd, env=env)
-    else:
-        subprocess.call(cmd, env=env)
+    _run_apt_command(cmd, fatal)
 
 
 def apt_upgrade(options=None, fatal=False, dist=False):
@@ -109,24 +160,13 @@
     else:
         cmd.append('upgrade')
     log("Upgrading with options: {}".format(options))
-
-    env = os.environ.copy()
-    if 'DEBIAN_FRONTEND' not in env:
-        env['DEBIAN_FRONTEND'] = 'noninteractive'
-
-    if fatal:
-        subprocess.check_call(cmd, env=env)
-    else:
-        subprocess.call(cmd, env=env)
+    _run_apt_command(cmd, fatal)
 
 
 def apt_update(fatal=False):
     """Update local apt cache"""
     cmd = ['apt-get', 'update']
-    if fatal:
-        subprocess.check_call(cmd)
-    else:
-        subprocess.call(cmd)
+    _run_apt_command(cmd, fatal)
 
 
 def apt_purge(packages, fatal=False):
@@ -137,10 +177,7 @@
     else:
         cmd.extend(packages)
     log("Purging {}".format(packages))
-    if fatal:
-        subprocess.check_call(cmd)
-    else:
-        subprocess.call(cmd)
+    _run_apt_command(cmd, fatal)
 
 
 def apt_hold(packages, fatal=False):
@@ -151,6 +188,7 @@
     else:
         cmd.extend(packages)
     log("Holding {}".format(packages))
+
     if fatal:
         subprocess.check_call(cmd)
     else:
@@ -184,14 +222,10 @@
             apt.write(PROPOSED_POCKET.format(release))
     if key:
         subprocess.check_call(['apt-key', 'adv', '--keyserver',
-                               'keyserver.ubuntu.com', '--recv',
+                               'hkp://keyserver.ubuntu.com:80', '--recv',
                                key])
 
 
-class SourceConfigError(Exception):
-    pass
-
-
 def configure_sources(update=False,
                       sources_var='install_sources',
                       keys_var='install_keys'):
@@ -224,17 +258,6 @@
     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):
     """
@@ -265,30 +288,6 @@
     return install_remote(source)
 
 
-class BaseFetchHandler(object):
-
-    """Base class for FetchHandler implementations in fetch plugins"""
-
-    def can_handle(self, source):
-        """Returns True if the source can be handled. Otherwise returns
-        a string explaining why it cannot"""
-        return "Wrong source type"
-
-    def install(self, source):
-        """Try to download and unpack the source. Return the path to the
-        unpacked files or raise UnhandledSource."""
-        raise UnhandledSource("Wrong source type {}".format(source))
-
-    def parse_url(self, url):
-        return urlparse(url)
-
-    def base_url(self, url):
-        """Return url without querystring or fragment"""
-        parts = list(self.parse_url(url))
-        parts[4:] = ['' for i in parts[4:]]
-        return urlunparse(parts)
-
-
 def plugins(fetch_handlers=None):
     if not fetch_handlers:
         fetch_handlers = FETCH_HANDLERS
@@ -306,3 +305,40 @@
             log("FetchHandler {} not found, skipping plugin".format(
                 handler_name))
     return plugin_list
+
+
+def _run_apt_command(cmd, fatal=False):
+    """
+    Run an APT command, checking output and retrying if the fatal flag is set
+    to True.
+
+    :param: cmd: str: The apt command to run.
+    :param: fatal: bool: Whether the command's output should be checked and
+        retried.
+    """
+    env = os.environ.copy()
+
+    if 'DEBIAN_FRONTEND' not in env:
+        env['DEBIAN_FRONTEND'] = 'noninteractive'
+
+    if fatal:
+        retry_count = 0
+        result = None
+
+        # If the command is considered "fatal", we need to retry if the apt
+        # lock was not acquired.
+
+        while result is None or result == APT_NO_LOCK:
+            try:
+                result = subprocess.check_call(cmd, env=env)
+            except subprocess.CalledProcessError, e:
+                retry_count = retry_count + 1
+                if retry_count > APT_NO_LOCK_RETRY_COUNT:
+                    raise
+                result = e.returncode
+                log("Couldn't acquire DPKG lock. Will retry in {} seconds."
+                    "".format(APT_NO_LOCK_RETRY_DELAY))
+                time.sleep(APT_NO_LOCK_RETRY_DELAY)
+
+    else:
+        subprocess.call(cmd, env=env)

=== modified file 'hooks/charmhelpers/fetch/bzrurl.py'
--- hooks/charmhelpers/fetch/bzrurl.py	2013-12-17 15:33:05 +0000
+++ hooks/charmhelpers/fetch/bzrurl.py	2014-08-27 07:08:22 +0000
@@ -39,7 +39,8 @@
     def install(self, source):
         url_parts = self.parse_url(source)
         branch_name = url_parts.path.strip("/").split("/")[-1]
-        dest_dir = os.path.join(os.environ.get('CHARM_DIR'), "fetched", branch_name)
+        dest_dir = os.path.join(os.environ.get('CHARM_DIR'), "fetched",
+                                branch_name)
         if not os.path.exists(dest_dir):
             mkdir(dest_dir, perms=0755)
         try: