Merge ~james-page/ntpmaster-charm:add-update-status into ntpmaster-charm:master

[James Page]

[James Page (james-page)]

For reference:

Model Controller Cloud/Region Version
default lxd-localhost lxd/localhost 2.0.0

App Version Status Scale Charm Store Rev OS Notes
ntp 4.2.6.p5+dfsg active 2 ntp local 14 ubuntu
ntpmaster 4.2.6.p5+dfsg active 1 ntpmaster local 30 ubuntu
ubuntu 14.04 active 2 ubuntu jujucharms 8 ubuntu exposed

Unit Workload Agent Machine Public address Ports Message
ntpmaster/0* active idle 0 10.20.200.76 123/udp Unit is ready
ubuntu/0 active idle 1 10.20.200.25 ready
  ntp/1 active idle 10.20.200.25 Unit is ready
ubuntu/1* active idle 2 10.20.200.38 ready
  ntp/0* active idle 10.20.200.38 Unit is ready

Machine State DNS Inst id Series AZ
0 started 10.20.200.76 juju-983066-0 trusty
1 started 10.20.200.25 juju-983066-1 trusty
2 started 10.20.200.38 juju-983066-2 trusty

Relation Provides Consumes Type
ntp-peers ntp ntp peer
master ntp ntpmaster regular
juju-info ntp ubuntu regular
peer ntpmaster ntpmaster peer
juju-info ubuntu ntp subordinate

[Stuart Bishop (stub)]

Almost entirely charmhelpers sync.

The new hooks looks good and should do what it says on the tin.

I'm not here this week so somebody else gets to land this :)

review: Approve

[Paul Gear (paulgear)]

Merged; question about future use of status_set() in https://code.launchpad.net/~james-page/ntp-charm/+git/ntp-charm/+merge/308705 applies equally here.

diff --git a/.gitignore b/.gitignore
 new file mode 100644
index 0000000..ba077a4
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+bin
diff --git a/charm-helpers-sync.yaml b/charm-helpers-sync.yaml
index 7fd4ca6..c6dcfa3 100644
--- a/charm-helpers-sync.yaml
+++ b/charm-helpers-sync.yaml
@@ -1,5 +1,6 @@
 branch: lp:charm-helpers
 destination: hooks/charmhelpers
 include:
+    - osplatform
     - core
     - fetch
diff --git a/hooks/charmhelpers/__init__.py b/hooks/charmhelpers/__init__.py
index f72e7f8..4886788 100644
--- a/hooks/charmhelpers/__init__.py
+++ b/hooks/charmhelpers/__init__.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 # Bootstrap charm-helpers, installing its dependencies if necessary using
 # only standard libraries.
diff --git a/hooks/charmhelpers/core/__init__.py b/hooks/charmhelpers/core/__init__.py
index d1400a0..d7567b8 100644
--- a/hooks/charmhelpers/core/__init__.py
+++ b/hooks/charmhelpers/core/__init__.py
@@ -1,15 +1,13 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
diff --git a/hooks/charmhelpers/core/decorators.py b/hooks/charmhelpers/core/decorators.py
index bb05620..6ad41ee 100644
--- a/hooks/charmhelpers/core/decorators.py
+++ b/hooks/charmhelpers/core/decorators.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 #
 # Copyright 2014 Canonical Ltd.
diff --git a/hooks/charmhelpers/core/files.py b/hooks/charmhelpers/core/files.py
index 0f12d32..fdd82b7 100644
--- a/hooks/charmhelpers/core/files.py
+++ b/hooks/charmhelpers/core/files.py
@@ -3,19 +3,17 @@
 
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 __author__ = 'Jorge Niedbalski <[e-mail]>'
 
diff --git a/hooks/charmhelpers/core/fstab.py b/hooks/charmhelpers/core/fstab.py
index 3056fba..d9fa915 100644
--- a/hooks/charmhelpers/core/fstab.py
+++ b/hooks/charmhelpers/core/fstab.py
@@ -3,19 +3,17 @@
 
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import io
 import os
diff --git a/hooks/charmhelpers/core/hookenv.py b/hooks/charmhelpers/core/hookenv.py
index 0132129..996e81c 100644
--- a/hooks/charmhelpers/core/hookenv.py
+++ b/hooks/charmhelpers/core/hookenv.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 "Interactions with the Juju environment"
 # Copyright 2013 Canonical Ltd.
@@ -845,6 +843,20 @@ def translate_exc(from_exc, to_exc):
     return inner_translate_exc1
 
 
+def application_version_set(version):
+    """Charm authors may trigger this command from any hook to output what
+    version of the application is running. This could be a package version,
+    for instance postgres version 9.5. It could also be a build number or
+    version control revision identifier, for instance git sha 6fb7ba68. """
+
+    cmd = ['application-version-set']
+    cmd.append(version)
+    try:
+        subprocess.check_call(cmd)
+    except OSError:
+        log("Application Version: {}".format(version))
+
+
 @translate_exc(from_exc=OSError, to_exc=NotImplementedError)
 def is_leader():
     """Does the current unit hold the juju leadership
@@ -1006,4 +1018,4 @@ def network_get_primary_address(binding):
     :raise: NotImplementedError if run on Juju < 2.0
     '''
     cmd = ['network-get', '--primary-address', binding]
-    return subprocess.check_output(cmd).strip()
+    return subprocess.check_output(cmd).decode('UTF-8').strip()
diff --git a/hooks/charmhelpers/core/host.py b/hooks/charmhelpers/core/host.py
index bfea6a1..0f1b2f3 100644
--- a/hooks/charmhelpers/core/host.py
+++ b/hooks/charmhelpers/core/host.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 """Tools for working with the host system"""
 # Copyright 2012 Canonical Ltd.
@@ -32,13 +30,29 @@ import subprocess
 import hashlib
 import functools
 import itertools
-from contextlib import contextmanager
-from collections import OrderedDict
-
 import six
 
+from contextlib import contextmanager
+from collections import OrderedDict
 from .hookenv import log
 from .fstab import Fstab
+from charmhelpers.osplatform import get_platform
+
+__platform__ = get_platform()
+if __platform__ == "ubuntu":
+    from charmhelpers.core.host_factory.ubuntu import (
+        service_available,
+        add_new_group,
+        lsb_release,
+        cmp_pkgrevno,
+    )  # flake8: noqa -- ignore F401 for this import
+elif __platform__ == "centos":
+    from charmhelpers.core.host_factory.centos import (
+        service_available,
+        add_new_group,
+        lsb_release,
+        cmp_pkgrevno,
+    )  # flake8: noqa -- ignore F401 for this import
 
 
 def service_start(service_name):
@@ -128,11 +142,8 @@ def service(action, service_name):
     return subprocess.call(cmd) == 0
 
 
-def systemv_services_running():
-    output = subprocess.check_output(
-        ['service', '--status-all'],
-        stderr=subprocess.STDOUT).decode('UTF-8')
-    return [row.split()[-1] for row in output.split('\n') if '[ + ]' in row]
+_UPSTART_CONF = "/etc/init/{}.conf"
+_INIT_D_CONF = "/etc/init.d/{}"
 
 
 def service_running(service_name):
@@ -140,34 +151,25 @@ def service_running(service_name):
     if init_is_systemd():
         return service('is-active', service_name)
     else:
-        try:
-            output = subprocess.check_output(
-                ['service', service_name, 'status'],
-                stderr=subprocess.STDOUT).decode('UTF-8')
-        except subprocess.CalledProcessError:
-            return False
-        else:
-            # This works for upstart scripts where the 'service' command
-            # returns a consistent string to represent running 'start/running'
-            if ("start/running" in output or "is running" in output or
-                    "up and running" in output):
-                return True
+        if os.path.exists(_UPSTART_CONF.format(service_name)):
+            try:
+                output = subprocess.check_output(
+                    ['status', service_name],
+                    stderr=subprocess.STDOUT).decode('UTF-8')
+            except subprocess.CalledProcessError:
+                return False
+            else:
+                # This works for upstart scripts where the 'service' command
+                # returns a consistent string to represent running
+                # 'start/running'
+                if ("start/running" in output or
+                        "is running" in output or
+                        "up and running" in output):
+                    return True
+        elif os.path.exists(_INIT_D_CONF.format(service_name)):
             # Check System V scripts init script return codes
-            if service_name in systemv_services_running():
-                return True
-            return False
-
-
-def service_available(service_name):
-    """Determine whether a system service is available"""
-    try:
-        subprocess.check_output(
-            ['service', service_name, 'status'],
-            stderr=subprocess.STDOUT).decode('UTF-8')
-    except subprocess.CalledProcessError as e:
-        return b'unrecognized service' not in e.output
-    else:
-        return True
+            return service('status', service_name)
+        return False
 
 
 SYSTEMD_SYSTEM = '/run/systemd/system'
@@ -178,8 +180,9 @@ def init_is_systemd():
     return os.path.isdir(SYSTEMD_SYSTEM)
 
 
-def adduser(username, password=None, shell='/bin/bash', system_user=False,
-            primary_group=None, secondary_groups=None):
+def adduser(username, password=None, shell='/bin/bash',
+            system_user=False, primary_group=None,
+            secondary_groups=None, uid=None, home_dir=None):
     """Add a user to the system.
 
     Will log but otherwise succeed if the user already exists.
@@ -190,15 +193,24 @@ def adduser(username, password=None, shell='/bin/bash', system_user=False,
     :param bool system_user: Whether to create a login or system user
     :param str primary_group: Primary group for user; defaults to username
     :param list secondary_groups: Optional list of additional groups
+    :param int uid: UID for user being created
+    :param str home_dir: Home directory for user
 
     :returns: The password database entry struct, as returned by `pwd.getpwnam`
     """
     try:
         user_info = pwd.getpwnam(username)
         log('user {0} already exists!'.format(username))
+        if uid:
+            user_info = pwd.getpwuid(int(uid))
+            log('user with uid {0} already exists!'.format(uid))
     except KeyError:
         log('creating user {0}'.format(username))
         cmd = ['useradd']
+        if uid:
+            cmd.extend(['--uid', str(uid)])
+        if home_dir:
+            cmd.extend(['--home', str(home_dir)])
         if system_user or password is None:
             cmd.append('--system')
         else:
@@ -233,22 +245,56 @@ def user_exists(username):
     return user_exists
 
 
-def add_group(group_name, system_group=False):
-    """Add a group to the system"""
+def uid_exists(uid):
+    """Check if a uid exists"""
+    try:
+        pwd.getpwuid(uid)
+        uid_exists = True
+    except KeyError:
+        uid_exists = False
+    return uid_exists
+
+
+def group_exists(groupname):
+    """Check if a group exists"""
+    try:
+        grp.getgrnam(groupname)
+        group_exists = True
+    except KeyError:
+        group_exists = False
+    return group_exists
+
+
+def gid_exists(gid):
+    """Check if a gid exists"""
+    try:
+        grp.getgrgid(gid)
+        gid_exists = True
+    except KeyError:
+        gid_exists = False
+    return gid_exists
+
+
+def add_group(group_name, system_group=False, gid=None):
+    """Add a group to the system
+
+    Will log but otherwise succeed if the group already exists.
+
+    :param str group_name: group to create
+    :param bool system_group: Create system group
+    :param int gid: GID for user being created
+
+    :returns: The password database entry struct, as returned by `grp.getgrnam`
+    """
     try:
         group_info = grp.getgrnam(group_name)
         log('group {0} already exists!'.format(group_name))
+        if gid:
+            group_info = grp.getgrgid(gid)
+            log('group with gid {0} already exists!'.format(gid))
     except KeyError:
         log('creating group {0}'.format(group_name))
-        cmd = ['addgroup']
-        if system_group:
-            cmd.append('--system')
-        else:
-            cmd.extend([
-                '--group',
-            ])
-        cmd.append(group_name)
-        subprocess.check_call(cmd)
+        add_new_group(group_name, system_group, gid)
         group_info = grp.getgrnam(group_name)
     return group_info
 
@@ -493,16 +539,6 @@ def restart_on_change_helper(lambda_f, restart_map, stopstart=False,
     return r
 
 
-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:
@@ -626,25 +662,6 @@ def get_nic_hwaddr(nic):
     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
-
-    This function imports apt_cache function from charmhelpers.fetch if
-    the pkgcache argument is None. Be sure to add charmhelpers.fetch if
-    you call this function, or pass an apt_pkg.Cache() instance.
-    """
-    import apt_pkg
-    if not pkgcache:
-        from charmhelpers.fetch import apt_cache
-        pkgcache = apt_cache()
-    pkg = pkgcache[package]
-    return apt_pkg.version_compare(pkg.current_ver.ver_str, revno)
-
-
 @contextmanager
 def chdir(directory):
     """Change the current working directory to a different directory for a code
diff --git a/hooks/charmhelpers/core/host_factory/__init__.py b/hooks/charmhelpers/core/host_factory/__init__.py
 new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/hooks/charmhelpers/core/host_factory/__init__.py
diff --git a/hooks/charmhelpers/core/host_factory/centos.py b/hooks/charmhelpers/core/host_factory/centos.py
 new file mode 100644
index 0000000..902d469
--- /dev/null
+++ b/hooks/charmhelpers/core/host_factory/centos.py
@@ -0,0 +1,56 @@
+import subprocess
+import yum
+import os
+
+
+def service_available(service_name):
+    # """Determine whether a system service is available."""
+    if os.path.isdir('/run/systemd/system'):
+        cmd = ['systemctl', 'is-enabled', service_name]
+    else:
+        cmd = ['service', service_name, 'is-enabled']
+    return subprocess.call(cmd) == 0
+
+
+def add_new_group(group_name, system_group=False, gid=None):
+    cmd = ['groupadd']
+    if gid:
+        cmd.extend(['--gid', str(gid)])
+    if system_group:
+        cmd.append('-r')
+    cmd.append(group_name)
+    subprocess.check_call(cmd)
+
+
+def lsb_release():
+    """Return /etc/os-release in a dict."""
+    d = {}
+    with open('/etc/os-release', 'r') as lsb:
+        for l in lsb:
+            s = l.split('=')
+            if len(s) != 2:
+                continue
+            d[s[0].strip()] = s[1].strip()
+    return d
+
+
+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
+
+    This function imports YumBase function if the pkgcache argument
+    is None.
+    """
+    if not pkgcache:
+        y = yum.YumBase()
+        packages = y.doPackageLists()
+        pkgcache = {i.Name: i.version for i in packages['installed']}
+    pkg = pkgcache[package]
+    if pkg > revno:
+        return 1
+    if pkg < revno:
+        return -1
+    return 0
diff --git a/hooks/charmhelpers/core/host_factory/ubuntu.py b/hooks/charmhelpers/core/host_factory/ubuntu.py
 new file mode 100644
index 0000000..8c66af5
--- /dev/null
+++ b/hooks/charmhelpers/core/host_factory/ubuntu.py
@@ -0,0 +1,56 @@
+import subprocess
+
+
+def service_available(service_name):
+    """Determine whether a system service is available"""
+    try:
+        subprocess.check_output(
+            ['service', service_name, 'status'],
+            stderr=subprocess.STDOUT).decode('UTF-8')
+    except subprocess.CalledProcessError as e:
+        return b'unrecognized service' not in e.output
+    else:
+        return True
+
+
+def add_new_group(group_name, system_group=False, gid=None):
+    cmd = ['addgroup']
+    if gid:
+        cmd.extend(['--gid', str(gid)])
+    if system_group:
+        cmd.append('--system')
+    else:
+        cmd.extend([
+            '--group',
+        ])
+    cmd.append(group_name)
+    subprocess.check_call(cmd)
+
+
+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 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
+
+    This function imports apt_cache function from charmhelpers.fetch if
+    the pkgcache argument is None. Be sure to add charmhelpers.fetch if
+    you call this function, or pass an apt_pkg.Cache() instance.
+    """
+    import apt_pkg
+    if not pkgcache:
+        from charmhelpers.fetch import apt_cache
+        pkgcache = apt_cache()
+    pkg = pkgcache[package]
+    return apt_pkg.version_compare(pkg.current_ver.ver_str, revno)
diff --git a/hooks/charmhelpers/core/hugepage.py b/hooks/charmhelpers/core/hugepage.py
index a783ad9..54b5b5e 100644
--- a/hooks/charmhelpers/core/hugepage.py
+++ b/hooks/charmhelpers/core/hugepage.py
@@ -2,19 +2,17 @@
 
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import yaml
 from charmhelpers.core import fstab
diff --git a/hooks/charmhelpers/core/kernel.py b/hooks/charmhelpers/core/kernel.py
index 5dc6495..2d40452 100644
--- a/hooks/charmhelpers/core/kernel.py
+++ b/hooks/charmhelpers/core/kernel.py
@@ -3,29 +3,40 @@
 
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
-__author__ = "Jorge Niedbalski <[e-mail]>"
+import re
+import subprocess
 
+from charmhelpers.osplatform import get_platform
 from charmhelpers.core.hookenv import (
     log,
     INFO
 )
 
-from subprocess import check_call, check_output
-import re
+__platform__ = get_platform()
+if __platform__ == "ubuntu":
+    from charmhelpers.core.kernel_factory.ubuntu import (
+        persistent_modprobe,
+        update_initramfs,
+    )  # flake8: noqa -- ignore F401 for this import
+elif __platform__ == "centos":
+    from charmhelpers.core.kernel_factory.centos import (
+        persistent_modprobe,
+        update_initramfs,
+    )  # flake8: noqa -- ignore F401 for this import
+
+__author__ = "Jorge Niedbalski <[e-mail]>"
 
 
 def modprobe(module, persist=True):
@@ -34,11 +45,9 @@ def modprobe(module, persist=True):
 
     log('Loading kernel module %s' % module, level=INFO)
 
-    check_call(cmd)
+    subprocess.check_call(cmd)
     if persist:
-        with open('/etc/modules', 'r+') as modules:
-            if module not in modules.read():
-                modules.write(module)
+        persistent_modprobe(module)
 
 
 def rmmod(module, force=False):
@@ -48,21 +57,16 @@ def rmmod(module, force=False):
         cmd.append('-f')
     cmd.append(module)
     log('Removing kernel module %s' % module, level=INFO)
-    return check_call(cmd)
+    return subprocess.check_call(cmd)
 
 
 def lsmod():
     """Shows what kernel modules are currently loaded"""
-    return check_output(['lsmod'],
-                        universal_newlines=True)
+    return subprocess.check_output(['lsmod'],
+                                   universal_newlines=True)
 
 
 def is_module_loaded(module):
     """Checks if a kernel module is already loaded"""
     matches = re.findall('^%s[ ]+' % module, lsmod(), re.M)
     return len(matches) > 0
-
-
-def update_initramfs(version='all'):
-    """Updates an initramfs image"""
-    return check_call(["update-initramfs", "-k", version, "-u"])
diff --git a/hooks/charmhelpers/core/kernel_factory/__init__.py b/hooks/charmhelpers/core/kernel_factory/__init__.py
 new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/hooks/charmhelpers/core/kernel_factory/__init__.py
diff --git a/hooks/charmhelpers/core/kernel_factory/centos.py b/hooks/charmhelpers/core/kernel_factory/centos.py
 new file mode 100644
index 0000000..1c402c1
--- /dev/null
+++ b/hooks/charmhelpers/core/kernel_factory/centos.py
@@ -0,0 +1,17 @@
+import subprocess
+import os
+
+
+def persistent_modprobe(module):
+    """Load a kernel module and configure for auto-load on reboot."""
+    if not os.path.exists('/etc/rc.modules'):
+        open('/etc/rc.modules', 'a')
+        os.chmod('/etc/rc.modules', 111)
+    with open('/etc/rc.modules', 'r+') as modules:
+        if module not in modules.read():
+            modules.write('modprobe %s\n' % module)
+
+
+def update_initramfs(version='all'):
+    """Updates an initramfs image."""
+    return subprocess.check_call(["dracut", "-f", version])
diff --git a/hooks/charmhelpers/core/kernel_factory/ubuntu.py b/hooks/charmhelpers/core/kernel_factory/ubuntu.py
 new file mode 100644
index 0000000..2155964
--- /dev/null
+++ b/hooks/charmhelpers/core/kernel_factory/ubuntu.py
@@ -0,0 +1,13 @@
+import subprocess
+
+
+def persistent_modprobe(module):
+    """Load a kernel module and configure for auto-load on reboot."""
+    with open('/etc/modules', 'r+') as modules:
+        if module not in modules.read():
+            modules.write(module)
+
+
+def update_initramfs(version='all'):
+    """Updates an initramfs image."""
+    return subprocess.check_call(["update-initramfs", "-k", version, "-u"])
diff --git a/hooks/charmhelpers/core/services/__init__.py b/hooks/charmhelpers/core/services/__init__.py
index 0928158..61fd074 100644
--- a/hooks/charmhelpers/core/services/__init__.py
+++ b/hooks/charmhelpers/core/services/__init__.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 from .base import *  # NOQA
 from .helpers import *  # NOQA
diff --git a/hooks/charmhelpers/core/services/base.py b/hooks/charmhelpers/core/services/base.py
index a42660c..ca9dc99 100644
--- a/hooks/charmhelpers/core/services/base.py
+++ b/hooks/charmhelpers/core/services/base.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import os
 import json
diff --git a/hooks/charmhelpers/core/services/helpers.py b/hooks/charmhelpers/core/services/helpers.py
index 2423704..3e6e30d 100644
--- a/hooks/charmhelpers/core/services/helpers.py
+++ b/hooks/charmhelpers/core/services/helpers.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import os
 import yaml
diff --git a/hooks/charmhelpers/core/strutils.py b/hooks/charmhelpers/core/strutils.py
index 7e3f969..dd9b971 100644
--- a/hooks/charmhelpers/core/strutils.py
+++ b/hooks/charmhelpers/core/strutils.py
@@ -3,19 +3,17 @@
 
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import six
 import re
diff --git a/hooks/charmhelpers/core/sysctl.py b/hooks/charmhelpers/core/sysctl.py
index 21cc8ab..6e413e3 100644
--- a/hooks/charmhelpers/core/sysctl.py
+++ b/hooks/charmhelpers/core/sysctl.py
@@ -3,19 +3,17 @@
 
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import yaml
 
diff --git a/hooks/charmhelpers/core/templating.py b/hooks/charmhelpers/core/templating.py
index d2d8eaf..7b801a3 100644
--- a/hooks/charmhelpers/core/templating.py
+++ b/hooks/charmhelpers/core/templating.py
@@ -1,20 +1,19 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import os
+import sys
 
 from charmhelpers.core import host
 from charmhelpers.core import hookenv
@@ -40,8 +39,9 @@ def render(source, target, context, owner='root', group='root',
     The rendered template will be written to the file as well as being returned
     as a string.
 
-    Note: Using this requires python-jinja2; if it is not installed, calling
-    this will attempt to use charmhelpers.fetch.apt_install to install it.
+    Note: Using this requires python-jinja2 or python3-jinja2; if it is not
+    installed, calling this will attempt to use charmhelpers.fetch.apt_install
+    to install it.
     """
     try:
         from jinja2 import FileSystemLoader, Environment, exceptions
@@ -53,7 +53,10 @@ def render(source, target, context, owner='root', group='root',
                         'charmhelpers.fetch to install it',
                         level=hookenv.ERROR)
             raise
-        apt_install('python-jinja2', fatal=True)
+        if sys.version_info.major == 2:
+            apt_install('python-jinja2', fatal=True)
+        else:
+            apt_install('python3-jinja2', fatal=True)
         from jinja2 import FileSystemLoader, Environment, exceptions
 
     if template_loader:
diff --git a/hooks/charmhelpers/core/unitdata.py b/hooks/charmhelpers/core/unitdata.py
index 338104e..54ec969 100644
--- a/hooks/charmhelpers/core/unitdata.py
+++ b/hooks/charmhelpers/core/unitdata.py
@@ -3,20 +3,17 @@
 #
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
-#
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 #
 # Authors:
 #  Kapil Thangavelu <[e-mail]>
diff --git a/hooks/charmhelpers/fetch/__init__.py b/hooks/charmhelpers/fetch/__init__.py
index db0d86a..ec5e0fe 100644
--- a/hooks/charmhelpers/fetch/__init__.py
+++ b/hooks/charmhelpers/fetch/__init__.py
@@ -1,32 +1,24 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import importlib
-from tempfile import NamedTemporaryFile
-import time
+from charmhelpers.osplatform import get_platform
 from yaml import safe_load
-from charmhelpers.core.host import (
-    lsb_release
-)
-import subprocess
 from charmhelpers.core.hookenv import (
     config,
     log,
 )
-import os
 
 import six
 if six.PY3:
@@ -35,79 +27,6 @@ else:
     from urlparse import urlparse, urlunparse
 
 
-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',
-    'precise-havana/proposed': 'precise-proposed/havana',
-    'precise-proposed/havana': 'precise-proposed/havana',
-    # Icehouse
-    'icehouse': 'precise-updates/icehouse',
-    'precise-icehouse': 'precise-updates/icehouse',
-    'precise-icehouse/updates': 'precise-updates/icehouse',
-    'precise-updates/icehouse': 'precise-updates/icehouse',
-    'icehouse/proposed': 'precise-proposed/icehouse',
-    'precise-icehouse/proposed': 'precise-proposed/icehouse',
-    'precise-proposed/icehouse': 'precise-proposed/icehouse',
-    # Juno
-    'juno': 'trusty-updates/juno',
-    'trusty-juno': 'trusty-updates/juno',
-    'trusty-juno/updates': 'trusty-updates/juno',
-    'trusty-updates/juno': 'trusty-updates/juno',
-    'juno/proposed': 'trusty-proposed/juno',
-    'trusty-juno/proposed': 'trusty-proposed/juno',
-    'trusty-proposed/juno': 'trusty-proposed/juno',
-    # Kilo
-    'kilo': 'trusty-updates/kilo',
-    'trusty-kilo': 'trusty-updates/kilo',
-    'trusty-kilo/updates': 'trusty-updates/kilo',
-    'trusty-updates/kilo': 'trusty-updates/kilo',
-    'kilo/proposed': 'trusty-proposed/kilo',
-    'trusty-kilo/proposed': 'trusty-proposed/kilo',
-    'trusty-proposed/kilo': 'trusty-proposed/kilo',
-    # Liberty
-    'liberty': 'trusty-updates/liberty',
-    'trusty-liberty': 'trusty-updates/liberty',
-    'trusty-liberty/updates': 'trusty-updates/liberty',
-    'trusty-updates/liberty': 'trusty-updates/liberty',
-    'liberty/proposed': 'trusty-proposed/liberty',
-    'trusty-liberty/proposed': 'trusty-proposed/liberty',
-    'trusty-proposed/liberty': 'trusty-proposed/liberty',
-    # Mitaka
-    'mitaka': 'trusty-updates/mitaka',
-    'trusty-mitaka': 'trusty-updates/mitaka',
-    'trusty-mitaka/updates': 'trusty-updates/mitaka',
-    'trusty-updates/mitaka': 'trusty-updates/mitaka',
-    'mitaka/proposed': 'trusty-proposed/mitaka',
-    'trusty-mitaka/proposed': 'trusty-proposed/mitaka',
-    'trusty-proposed/mitaka': 'trusty-proposed/mitaka',
-}
-
 # The order of this list is very important. Handlers should be listed in from
 # least- to most-specific URL matching.
 FETCH_HANDLERS = (
@@ -116,10 +35,6 @@ FETCH_HANDLERS = (
     'charmhelpers.fetch.giturl.GitUrlFetchHandler',
 )
 
-APT_NO_LOCK = 100  # The return code for "couldn't acquire lock" in APT.
-APT_NO_LOCK_RETRY_DELAY = 10  # Wait 10 seconds between apt lock checks.
-APT_NO_LOCK_RETRY_COUNT = 30  # Retry to acquire the lock X times.
-
 
 class SourceConfigError(Exception):
     pass
@@ -157,180 +72,38 @@ class BaseFetchHandler(object):
         return urlunparse(parts)
 
 
-def filter_installed_packages(packages):
-    """Returns a list of packages that require installation"""
-    cache = apt_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_cache(in_memory=True):
-    """Build and return an apt cache"""
-    from apt import apt_pkg
-    apt_pkg.init()
-    if in_memory:
-        apt_pkg.config.set("Dir::Cache::pkgcache", "")
-        apt_pkg.config.set("Dir::Cache::srcpkgcache", "")
-    return apt_pkg.Cache()
-
-
-def apt_install(packages, options=None, fatal=False):
-    """Install one or more packages"""
-    if options is None:
-        options = ['--option=Dpkg::Options::=--force-confold']
-
-    cmd = ['apt-get', '--assume-yes']
-    cmd.extend(options)
-    cmd.append('install')
-    if isinstance(packages, six.string_types):
-        cmd.append(packages)
-    else:
-        cmd.extend(packages)
-    log("Installing {} with options: {}".format(packages,
-                                                options))
-    _run_apt_command(cmd, fatal)
-
-
-def apt_upgrade(options=None, fatal=False, dist=False):
-    """Upgrade all packages"""
-    if options is None:
-        options = ['--option=Dpkg::Options::=--force-confold']
-
-    cmd = ['apt-get', '--assume-yes']
-    cmd.extend(options)
-    if dist:
-        cmd.append('dist-upgrade')
-    else:
-        cmd.append('upgrade')
-    log("Upgrading with options: {}".format(options))
-    _run_apt_command(cmd, fatal)
-
-
-def apt_update(fatal=False):
-    """Update local apt cache"""
-    cmd = ['apt-get', 'update']
-    _run_apt_command(cmd, fatal)
-
-
-def apt_purge(packages, fatal=False):
-    """Purge one or more packages"""
-    cmd = ['apt-get', '--assume-yes', 'purge']
-    if isinstance(packages, six.string_types):
-        cmd.append(packages)
-    else:
-        cmd.extend(packages)
-    log("Purging {}".format(packages))
-    _run_apt_command(cmd, fatal)
-
-
-def apt_mark(packages, mark, fatal=False):
-    """Flag one or more packages using apt-mark"""
-    log("Marking {} as {}".format(packages, mark))
-    cmd = ['apt-mark', mark]
-    if isinstance(packages, six.string_types):
-        cmd.append(packages)
-    else:
-        cmd.extend(packages)
-
-    if fatal:
-        subprocess.check_call(cmd, universal_newlines=True)
-    else:
-        subprocess.call(cmd, universal_newlines=True)
+__platform__ = get_platform()
+module = "charmhelpers.fetch.%s" % __platform__
+fetch = importlib.import_module(module)
 
+filter_installed_packages = fetch.filter_installed_packages
+install = fetch.install
+upgrade = fetch.upgrade
+update = fetch.update
+purge = fetch.purge
+add_source = fetch.add_source
 
-def apt_hold(packages, fatal=False):
-    return apt_mark(packages, 'hold', fatal=fatal)
-
-
-def apt_unhold(packages, fatal=False):
-    return apt_mark(packages, 'unhold', fatal=fatal)
-
-
-def add_source(source, key=None):
-    """Add a package source to this system.
-
-    @param source: a URL or sources.list entry, as supported by
-    add-apt-repository(1). Examples::
-
-        ppa:charmers/example
-        deb https://stub:[e-mail]/ubuntu trusty main
-
-    In addition:
-        'proposed:' may be used to enable the standard 'proposed'
-        pocket for the release.
-        'cloud:' may be used to activate official cloud archive pockets,
-        such as 'cloud:icehouse'
-        'distro' may be used as a noop
-
-    @param key: A key to be added to the system's APT keyring and used
-    to verify the signatures on packages. Ideally, this should be an
-    ASCII format GPG public key including the block headers. A GPG key
-    id may also be used, but be aware that only insecure protocols are
-    available to retrieve the actual public key from a public keyserver
-    placing your Juju environment at risk. ppa and cloud archive keys
-    are securely added automtically, so sould not be provided.
-    """
-    if source is None:
-        log('Source is not present. Skipping')
-        return
-
-    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))
-    elif source == 'distro':
-        pass
-    else:
-        log("Unknown source: {!r}".format(source))
-
-    if key:
-        if '-----BEGIN PGP PUBLIC KEY BLOCK-----' in key:
-            with NamedTemporaryFile('w+') as key_file:
-                key_file.write(key)
-                key_file.flush()
-                key_file.seek(0)
-                subprocess.check_call(['apt-key', 'add', '-'], stdin=key_file)
-        else:
-            # Note that hkp: is in no way a secure protocol. Using a
-            # GPG key id is pointless from a security POV unless you
-            # absolutely trust your network and DNS.
-            subprocess.check_call(['apt-key', 'adv', '--keyserver',
-                                   'hkp://keyserver.ubuntu.com:80', '--recv',
-                                   key])
+if __platform__ == "ubuntu":
+    apt_cache = fetch.apt_cache
+    apt_install = fetch.install
+    apt_update = fetch.update
+    apt_upgrade = fetch.upgrade
+    apt_purge = fetch.purge
+    apt_mark = fetch.apt_mark
+    apt_hold = fetch.apt_hold
+    apt_unhold = fetch.apt_unhold
+    get_upstream_version = fetch.get_upstream_version
+elif __platform__ == "centos":
+    yum_search = fetch.yum_search
 
 
 def configure_sources(update=False,
                       sources_var='install_sources',
                       keys_var='install_keys'):
-    """
-    Configure multiple sources from charm configuration.
+    """Configure multiple sources from charm configuration.
 
     The lists are encoded as yaml fragments in the configuration.
-    The frament needs to be included as a string. Sources and their
+    The fragment needs to be included as a string. Sources and their
     corresponding keys are of the types supported by add_source().
 
     Example config:
@@ -362,12 +135,11 @@ def configure_sources(update=False,
         for source, key in zip(sources, keys):
             add_source(source, key)
     if update:
-        apt_update(fatal=True)
+        fetch.update(fatal=True)
 
 
 def install_remote(source, *args, **kwargs):
-    """
-    Install a file tree from a 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][&...]]
@@ -390,19 +162,17 @@ def install_remote(source, *args, **kwargs):
     # 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, *args, **kwargs)
+            return handler.install(source, *args, **kwargs)
         except UnhandledSource as e:
             log('Install source attempt unsuccessful: {}'.format(e),
                 level='WARNING')
-    if not installed_to:
-        raise UnhandledSource("No handler found for source {}".format(source))
-    return installed_to
+    raise UnhandledSource("No handler found for source {}".format(source))
 
 
 def install_from_config(config_var_name):
+    """Install a file from config."""
     charm_config = config()
     source = charm_config[config_var_name]
     return install_remote(source)
@@ -425,40 +195,3 @@ def plugins(fetch_handlers=None):
             log("FetchHandler {} not found, skipping plugin".format(
                 handler_name))
     return plugin_list
-
-
-def _run_apt_command(cmd, fatal=False):
-    """
-    Run an APT command, checking output and retrying if the fatal flag is set
-    to True.
-
-    :param: cmd: str: The apt command to run.
-    :param: fatal: bool: Whether the command's output should be checked and
-        retried.
-    """
-    env = os.environ.copy()
-
-    if 'DEBIAN_FRONTEND' not in env:
-        env['DEBIAN_FRONTEND'] = 'noninteractive'
-
-    if fatal:
-        retry_count = 0
-        result = None
-
-        # If the command is considered "fatal", we need to retry if the apt
-        # lock was not acquired.
-
-        while result is None or result == APT_NO_LOCK:
-            try:
-                result = subprocess.check_call(cmd, env=env)
-            except subprocess.CalledProcessError as e:
-                retry_count = retry_count + 1
-                if retry_count > APT_NO_LOCK_RETRY_COUNT:
-                    raise
-                result = e.returncode
-                log("Couldn't acquire DPKG lock. Will retry in {} seconds."
-                    "".format(APT_NO_LOCK_RETRY_DELAY))
-                time.sleep(APT_NO_LOCK_RETRY_DELAY)
-
-    else:
-        subprocess.call(cmd, env=env)
diff --git a/hooks/charmhelpers/fetch/archiveurl.py b/hooks/charmhelpers/fetch/archiveurl.py
index b8e0943..dd24f9e 100644
--- a/hooks/charmhelpers/fetch/archiveurl.py
+++ b/hooks/charmhelpers/fetch/archiveurl.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import os
 import hashlib
diff --git a/hooks/charmhelpers/fetch/bzrurl.py b/hooks/charmhelpers/fetch/bzrurl.py
index cafd27f..07cd029 100644
--- a/hooks/charmhelpers/fetch/bzrurl.py
+++ b/hooks/charmhelpers/fetch/bzrurl.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import os
 from subprocess import check_call
@@ -20,19 +18,20 @@ from charmhelpers.fetch import (
     BaseFetchHandler,
     UnhandledSource,
     filter_installed_packages,
-    apt_install,
+    install,
 )
 from charmhelpers.core.host import mkdir
 
 
 if filter_installed_packages(['bzr']) != []:
-    apt_install(['bzr'])
+    install(['bzr'])
     if filter_installed_packages(['bzr']) != []:
         raise NotImplementedError('Unable to install bzr')
 
 
 class BzrUrlFetchHandler(BaseFetchHandler):
-    """Handler for bazaar branches via generic and lp URLs"""
+    """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', ''):
@@ -42,15 +41,23 @@ class BzrUrlFetchHandler(BaseFetchHandler):
         else:
             return True
 
-    def branch(self, source, dest):
+    def branch(self, source, dest, revno=None):
         if not self.can_handle(source):
             raise UnhandledSource("Cannot handle {}".format(source))
+        cmd_opts = []
+        if revno:
+            cmd_opts += ['-r', str(revno)]
         if os.path.exists(dest):
-            check_call(['bzr', 'pull', '--overwrite', '-d', dest, source])
+            cmd = ['bzr', 'pull']
+            cmd += cmd_opts
+            cmd += ['--overwrite', '-d', dest, source]
         else:
-            check_call(['bzr', 'branch', source, dest])
+            cmd = ['bzr', 'branch']
+            cmd += cmd_opts
+            cmd += [source, dest]
+        check_call(cmd)
 
-    def install(self, source, dest=None):
+    def install(self, source, dest=None, revno=None):
         url_parts = self.parse_url(source)
         branch_name = url_parts.path.strip("/").split("/")[-1]
         if dest:
@@ -59,10 +66,11 @@ class BzrUrlFetchHandler(BaseFetchHandler):
             dest_dir = os.path.join(os.environ.get('CHARM_DIR'), "fetched",
                                     branch_name)
 
-        if not os.path.exists(dest_dir):
-            mkdir(dest_dir, perms=0o755)
+        if dest and not os.path.exists(dest):
+            mkdir(dest, perms=0o755)
+
         try:
-            self.branch(source, dest_dir)
+            self.branch(source, dest_dir, revno)
         except OSError as e:
             raise UnhandledSource(e.strerror)
         return dest_dir
diff --git a/hooks/charmhelpers/fetch/centos.py b/hooks/charmhelpers/fetch/centos.py
 new file mode 100644
index 0000000..604bbfb
--- /dev/null
+++ b/hooks/charmhelpers/fetch/centos.py
@@ -0,0 +1,171 @@
+# Copyright 2014-2015 Canonical Limited.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import subprocess
+import os
+import time
+import six
+import yum
+
+from tempfile import NamedTemporaryFile
+from charmhelpers.core.hookenv import log
+
+YUM_NO_LOCK = 1  # The return code for "couldn't acquire lock" in YUM.
+YUM_NO_LOCK_RETRY_DELAY = 10  # Wait 10 seconds between apt lock checks.
+YUM_NO_LOCK_RETRY_COUNT = 30  # Retry to acquire the lock X times.
+
+
+def filter_installed_packages(packages):
+    """Return a list of packages that require installation."""
+    yb = yum.YumBase()
+    package_list = yb.doPackageLists()
+    temp_cache = {p.base_package_name: 1 for p in package_list['installed']}
+
+    _pkgs = [p for p in packages if not temp_cache.get(p, False)]
+    return _pkgs
+
+
+def install(packages, options=None, fatal=False):
+    """Install one or more packages."""
+    cmd = ['yum', '--assumeyes']
+    if options is not None:
+        cmd.extend(options)
+    cmd.append('install')
+    if isinstance(packages, six.string_types):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Installing {} with options: {}".format(packages,
+                                                options))
+    _run_yum_command(cmd, fatal)
+
+
+def upgrade(options=None, fatal=False, dist=False):
+    """Upgrade all packages."""
+    cmd = ['yum', '--assumeyes']
+    if options is not None:
+        cmd.extend(options)
+    cmd.append('upgrade')
+    log("Upgrading with options: {}".format(options))
+    _run_yum_command(cmd, fatal)
+
+
+def update(fatal=False):
+    """Update local yum cache."""
+    cmd = ['yum', '--assumeyes', 'update']
+    log("Update with fatal: {}".format(fatal))
+    _run_yum_command(cmd, fatal)
+
+
+def purge(packages, fatal=False):
+    """Purge one or more packages."""
+    cmd = ['yum', '--assumeyes', 'remove']
+    if isinstance(packages, six.string_types):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Purging {}".format(packages))
+    _run_yum_command(cmd, fatal)
+
+
+def yum_search(packages):
+    """Search for a package."""
+    output = {}
+    cmd = ['yum', 'search']
+    if isinstance(packages, six.string_types):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Searching for {}".format(packages))
+    result = subprocess.check_output(cmd)
+    for package in list(packages):
+        output[package] = package in result
+    return output
+
+
+def add_source(source, key=None):
+    """Add a package source to this system.
+
+    @param source: a URL with a rpm package
+
+    @param key: A key to be added to the system's keyring and used
+    to verify the signatures on packages. Ideally, this should be an
+    ASCII format GPG public key including the block headers. A GPG key
+    id may also be used, but be aware that only insecure protocols are
+    available to retrieve the actual public key from a public keyserver
+    placing your Juju environment at risk.
+    """
+    if source is None:
+        log('Source is not present. Skipping')
+        return
+
+    if source.startswith('http'):
+        directory = '/etc/yum.repos.d/'
+        for filename in os.listdir(directory):
+            with open(directory + filename, 'r') as rpm_file:
+                if source in rpm_file.read():
+                    break
+        else:
+            log("Add source: {!r}".format(source))
+            # write in the charms.repo
+            with open(directory + 'Charms.repo', 'a') as rpm_file:
+                rpm_file.write('[%s]\n' % source[7:].replace('/', '_'))
+                rpm_file.write('name=%s\n' % source[7:])
+                rpm_file.write('baseurl=%s\n\n' % source)
+    else:
+        log("Unknown source: {!r}".format(source))
+
+    if key:
+        if '-----BEGIN PGP PUBLIC KEY BLOCK-----' in key:
+            with NamedTemporaryFile('w+') as key_file:
+                key_file.write(key)
+                key_file.flush()
+                key_file.seek(0)
+            subprocess.check_call(['rpm', '--import', key_file])
+        else:
+            subprocess.check_call(['rpm', '--import', key])
+
+
+def _run_yum_command(cmd, fatal=False):
+    """Run an YUM command.
+
+    Checks the output and retry if the fatal flag is set to True.
+
+    :param: cmd: str: The yum command to run.
+    :param: fatal: bool: Whether the command's output should be checked and
+        retried.
+    """
+    env = os.environ.copy()
+
+    if fatal:
+        retry_count = 0
+        result = None
+
+        # If the command is considered "fatal", we need to retry if the yum
+        # lock was not acquired.
+
+        while result is None or result == YUM_NO_LOCK:
+            try:
+                result = subprocess.check_call(cmd, env=env)
+            except subprocess.CalledProcessError as e:
+                retry_count = retry_count + 1
+                if retry_count > YUM_NO_LOCK_RETRY_COUNT:
+                    raise
+                result = e.returncode
+                log("Couldn't acquire YUM lock. Will retry in {} seconds."
+                    "".format(YUM_NO_LOCK_RETRY_DELAY))
+                time.sleep(YUM_NO_LOCK_RETRY_DELAY)
+
+    else:
+        subprocess.call(cmd, env=env)
diff --git a/hooks/charmhelpers/fetch/giturl.py b/hooks/charmhelpers/fetch/giturl.py
index 65ed531..4cf21bc 100644
--- a/hooks/charmhelpers/fetch/giturl.py
+++ b/hooks/charmhelpers/fetch/giturl.py
@@ -1,18 +1,16 @@
 # Copyright 2014-2015 Canonical Limited.
 #
-# This file is part of charm-helpers.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# charm-helpers is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3 as
-# published by the Free Software Foundation.
+#  http://www.apache.org/licenses/LICENSE-2.0
 #
-# charm-helpers is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 
 import os
 from subprocess import check_call, CalledProcessError
@@ -20,17 +18,18 @@ from charmhelpers.fetch import (
     BaseFetchHandler,
     UnhandledSource,
     filter_installed_packages,
-    apt_install,
+    install,
 )
 
 if filter_installed_packages(['git']) != []:
-    apt_install(['git'])
+    install(['git'])
     if filter_installed_packages(['git']) != []:
         raise NotImplementedError('Unable to install git')
 
 
 class GitUrlFetchHandler(BaseFetchHandler):
-    """Handler for git branches via generic and github URLs"""
+    """Handler for git branches via generic and github URLs."""
+
     def can_handle(self, source):
         url_parts = self.parse_url(source)
         # TODO (mattyw) no support for ssh git@ yet
diff --git a/hooks/charmhelpers/fetch/ubuntu.py b/hooks/charmhelpers/fetch/ubuntu.py
 new file mode 100644
index 0000000..fce496b
--- /dev/null
+++ b/hooks/charmhelpers/fetch/ubuntu.py
@@ -0,0 +1,336 @@
+# Copyright 2014-2015 Canonical Limited.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import six
+import time
+import subprocess
+
+from tempfile import NamedTemporaryFile
+from charmhelpers.core.host import (
+    lsb_release
+)
+from charmhelpers.core.hookenv import log
+from charmhelpers.fetch import SourceConfigError
+
+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',
+    'precise-havana/proposed': 'precise-proposed/havana',
+    'precise-proposed/havana': 'precise-proposed/havana',
+    # Icehouse
+    'icehouse': 'precise-updates/icehouse',
+    'precise-icehouse': 'precise-updates/icehouse',
+    'precise-icehouse/updates': 'precise-updates/icehouse',
+    'precise-updates/icehouse': 'precise-updates/icehouse',
+    'icehouse/proposed': 'precise-proposed/icehouse',
+    'precise-icehouse/proposed': 'precise-proposed/icehouse',
+    'precise-proposed/icehouse': 'precise-proposed/icehouse',
+    # Juno
+    'juno': 'trusty-updates/juno',
+    'trusty-juno': 'trusty-updates/juno',
+    'trusty-juno/updates': 'trusty-updates/juno',
+    'trusty-updates/juno': 'trusty-updates/juno',
+    'juno/proposed': 'trusty-proposed/juno',
+    'trusty-juno/proposed': 'trusty-proposed/juno',
+    'trusty-proposed/juno': 'trusty-proposed/juno',
+    # Kilo
+    'kilo': 'trusty-updates/kilo',
+    'trusty-kilo': 'trusty-updates/kilo',
+    'trusty-kilo/updates': 'trusty-updates/kilo',
+    'trusty-updates/kilo': 'trusty-updates/kilo',
+    'kilo/proposed': 'trusty-proposed/kilo',
+    'trusty-kilo/proposed': 'trusty-proposed/kilo',
+    'trusty-proposed/kilo': 'trusty-proposed/kilo',
+    # Liberty
+    'liberty': 'trusty-updates/liberty',
+    'trusty-liberty': 'trusty-updates/liberty',
+    'trusty-liberty/updates': 'trusty-updates/liberty',
+    'trusty-updates/liberty': 'trusty-updates/liberty',
+    'liberty/proposed': 'trusty-proposed/liberty',
+    'trusty-liberty/proposed': 'trusty-proposed/liberty',
+    'trusty-proposed/liberty': 'trusty-proposed/liberty',
+    # Mitaka
+    'mitaka': 'trusty-updates/mitaka',
+    'trusty-mitaka': 'trusty-updates/mitaka',
+    'trusty-mitaka/updates': 'trusty-updates/mitaka',
+    'trusty-updates/mitaka': 'trusty-updates/mitaka',
+    'mitaka/proposed': 'trusty-proposed/mitaka',
+    'trusty-mitaka/proposed': 'trusty-proposed/mitaka',
+    'trusty-proposed/mitaka': 'trusty-proposed/mitaka',
+    # Newton
+    'newton': 'xenial-updates/newton',
+    'xenial-newton': 'xenial-updates/newton',
+    'xenial-newton/updates': 'xenial-updates/newton',
+    'xenial-updates/newton': 'xenial-updates/newton',
+    'newton/proposed': 'xenial-proposed/newton',
+    'xenial-newton/proposed': 'xenial-proposed/newton',
+    'xenial-proposed/newton': 'xenial-proposed/newton',
+}
+
+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.
+
+
+def filter_installed_packages(packages):
+    """Return a list of packages that require installation."""
+    cache = apt_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_cache(in_memory=True, progress=None):
+    """Build and return an apt cache."""
+    from apt import apt_pkg
+    apt_pkg.init()
+    if in_memory:
+        apt_pkg.config.set("Dir::Cache::pkgcache", "")
+        apt_pkg.config.set("Dir::Cache::srcpkgcache", "")
+    return apt_pkg.Cache(progress)
+
+
+def 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, six.string_types):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Installing {} with options: {}".format(packages,
+                                                options))
+    _run_apt_command(cmd, fatal)
+
+
+def upgrade(options=None, fatal=False, dist=False):
+    """Upgrade all packages."""
+    if options is None:
+        options = ['--option=Dpkg::Options::=--force-confold']
+
+    cmd = ['apt-get', '--assume-yes']
+    cmd.extend(options)
+    if dist:
+        cmd.append('dist-upgrade')
+    else:
+        cmd.append('upgrade')
+    log("Upgrading with options: {}".format(options))
+    _run_apt_command(cmd, fatal)
+
+
+def update(fatal=False):
+    """Update local apt cache."""
+    cmd = ['apt-get', 'update']
+    _run_apt_command(cmd, fatal)
+
+
+def purge(packages, fatal=False):
+    """Purge one or more packages."""
+    cmd = ['apt-get', '--assume-yes', 'purge']
+    if isinstance(packages, six.string_types):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+    log("Purging {}".format(packages))
+    _run_apt_command(cmd, fatal)
+
+
+def apt_mark(packages, mark, fatal=False):
+    """Flag one or more packages using apt-mark."""
+    log("Marking {} as {}".format(packages, mark))
+    cmd = ['apt-mark', mark]
+    if isinstance(packages, six.string_types):
+        cmd.append(packages)
+    else:
+        cmd.extend(packages)
+
+    if fatal:
+        subprocess.check_call(cmd, universal_newlines=True)
+    else:
+        subprocess.call(cmd, universal_newlines=True)
+
+
+def apt_hold(packages, fatal=False):
+    return apt_mark(packages, 'hold', fatal=fatal)
+
+
+def apt_unhold(packages, fatal=False):
+    return apt_mark(packages, 'unhold', fatal=fatal)
+
+
+def add_source(source, key=None):
+    """Add a package source to this system.
+
+    @param source: a URL or sources.list entry, as supported by
+    add-apt-repository(1). Examples::
+
+        ppa:charmers/example
+        deb https://stub:[e-mail]/ubuntu trusty main
+
+    In addition:
+        'proposed:' may be used to enable the standard 'proposed'
+        pocket for the release.
+        'cloud:' may be used to activate official cloud archive pockets,
+        such as 'cloud:icehouse'
+        'distro' may be used as a noop
+
+    @param key: A key to be added to the system's APT keyring and used
+    to verify the signatures on packages. Ideally, this should be an
+    ASCII format GPG public key including the block headers. A GPG key
+    id may also be used, but be aware that only insecure protocols are
+    available to retrieve the actual public key from a public keyserver
+    placing your Juju environment at risk. ppa and cloud archive keys
+    are securely added automtically, so sould not be provided.
+    """
+    if source is None:
+        log('Source is not present. Skipping')
+        return
+
+    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:'):
+        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))
+    elif source == 'distro':
+        pass
+    else:
+        log("Unknown source: {!r}".format(source))
+
+    if key:
+        if '-----BEGIN PGP PUBLIC KEY BLOCK-----' in key:
+            with NamedTemporaryFile('w+') as key_file:
+                key_file.write(key)
+                key_file.flush()
+                key_file.seek(0)
+                subprocess.check_call(['apt-key', 'add', '-'], stdin=key_file)
+        else:
+            # Note that hkp: is in no way a secure protocol. Using a
+            # GPG key id is pointless from a security POV unless you
+            # absolutely trust your network and DNS.
+            subprocess.check_call(['apt-key', 'adv', '--keyserver',
+                                   'hkp://keyserver.ubuntu.com:80', '--recv',
+                                   key])
+
+
+def _run_apt_command(cmd, fatal=False):
+    """Run an APT command.
+
+    Checks the output and retries if the fatal flag is set
+    to True.
+
+    :param: cmd: str: The apt command to run.
+    :param: fatal: bool: Whether the command's output should be checked and
+        retried.
+    """
+    env = os.environ.copy()
+
+    if 'DEBIAN_FRONTEND' not in env:
+        env['DEBIAN_FRONTEND'] = 'noninteractive'
+
+    if fatal:
+        retry_count = 0
+        result = None
+
+        # If the command is considered "fatal", we need to retry if the apt
+        # lock was not acquired.
+
+        while result is None or result == APT_NO_LOCK:
+            try:
+                result = subprocess.check_call(cmd, env=env)
+            except subprocess.CalledProcessError as e:
+                retry_count = retry_count + 1
+                if retry_count > APT_NO_LOCK_RETRY_COUNT:
+                    raise
+                result = e.returncode
+                log("Couldn't acquire DPKG lock. Will retry in {} seconds."
+                    "".format(APT_NO_LOCK_RETRY_DELAY))
+                time.sleep(APT_NO_LOCK_RETRY_DELAY)
+
+    else:
+        subprocess.call(cmd, env=env)
+
+
+def get_upstream_version(package):
+    """Determine upstream version based on installed package
+
+    @returns None (if not installed) or the upstream version
+    """
+    import apt_pkg
+    cache = apt_cache()
+    try:
+        pkg = cache[package]
+    except:
+        # the package is unknown to the current apt cache.
+        return None
+
+    if not pkg.current_ver:
+        # package is known, but no version is currently installed.
+        return None
+
+    return apt_pkg.upstream_version(pkg.current_ver.ver_str)
diff --git a/hooks/charmhelpers/osplatform.py b/hooks/charmhelpers/osplatform.py
 new file mode 100644
index 0000000..ea490bb
--- /dev/null
+++ b/hooks/charmhelpers/osplatform.py
@@ -0,0 +1,19 @@
+import platform
+
+
+def get_platform():
+    """Return the current OS platform.
+
+    For example: if current os platform is Ubuntu then a string "ubuntu"
+    will be returned (which is the name of the module).
+    This string is used to decide which platform module should be imported.
+    """
+    tuple_platform = platform.linux_distribution()
+    current_platform = tuple_platform[0]
+    if "Ubuntu" in current_platform:
+        return "ubuntu"
+    elif "CentOS" in current_platform:
+        return "centos"
+    else:
+        raise RuntimeError("This module is not supported on {}."
+                           .format(current_platform))
diff --git a/hooks/ntpmaster_hooks.py b/hooks/ntpmaster_hooks.py
index 979fbf0..1bbe8ce 100755
--- a/hooks/ntpmaster_hooks.py
+++ b/hooks/ntpmaster_hooks.py
@@ -65,8 +65,19 @@ def write_config():
         shutil.copy(NTP_CONF_ORIG, NTP_CONF)
 
 
+def assess_status():
+    hookenv.application_version_set(
+        fetch.get_upstream_version('ntp')
+    )
+    if host.service_running('ntp'):
+        hookenv.status_set('active', 'Unit is ready')
+    else:
+        hookenv.status_set('blocked', 'ntp not running')
+
+
 if __name__ == '__main__':
     try:
         hooks.execute(sys.argv)
     except UnregisteredHookError as e:
         hookenv.log('Unknown hook {} - skipping.'.format(e))
+    assess_status()
diff --git a/hooks/update-status b/hooks/update-status
 new file mode 120000
index 0000000..ce3b60a
--- /dev/null
+++ b/hooks/update-status
@@ -0,0 +1 @@
+ntpmaster_hooks.py
 \ No newline at end of file