Fix alphanumeric comparisons for openstack and ubuntu releases

- sync charmhelpers with fix-alpha helpers
- fix up code where the alpha comparisons are done
- fix tests which assumed mocks would just work on os_release()

Change-Id: I3d1a8993286f0e7a1037c03e6711015883f1b615
Related-Bug: #1659575

charm-helpers-tests.yaml

@@ -4,3 +4,4 @@ include:
     - contrib.amulet
     - contrib.openstack.amulet
     - core
+    - osplatform

hooks/charmhelpers/contrib/hardening/apache/checks/config.py

@@ -26,6 +26,7 @@ from charmhelpers.contrib.hardening.audits.file import (
     DirectoryPermissionAudit,
     NoReadWriteForOther,
     TemplatedFile,
+    DeletedFile
 )
 from charmhelpers.contrib.hardening.audits.apache import DisabledModuleAudit
 from charmhelpers.contrib.hardening.apache import TEMPLATES_DIR
@@ -52,13 +53,13 @@ def get_audits():
                                    'mods-available/alias.conf'),
                       context,
                       TEMPLATES_DIR,
-                      mode=0o0755,
+                      mode=0o0640,
                       user='root',
                       service_actions=[{'service': 'apache2',
                                         'actions': ['restart']}]),
 
         TemplatedFile(os.path.join(settings['common']['apache_dir'],
-                                   'conf-enabled/hardening.conf'),
+                                   'conf-enabled/99-hardening.conf'),
                       context,
                       TEMPLATES_DIR,
                       mode=0o0640,
@@ -69,11 +70,13 @@ def get_audits():
         DirectoryPermissionAudit(settings['common']['apache_dir'],
                                  user='root',
                                  group='root',
-                                 mode=0o640),
+                                 mode=0o0750),
 
         DisabledModuleAudit(settings['hardening']['modules_to_disable']),
 
         NoReadWriteForOther(settings['common']['apache_dir']),
+
+        DeletedFile(['/var/www/html/index.html'])
     ]
 
     return audits
@@ -94,5 +97,4 @@ class ApacheConfContext(object):
         ctxt['apache_version'] = re.search(r'.+version: Apache/(.+?)\s.+',
                                            out).group(1)
         ctxt['apache_icondir'] = '/usr/share/apache2/icons/'
-        ctxt['traceenable'] = settings['hardening']['traceenable']
         return ctxt

hooks/charmhelpers/contrib/hardening/apache/templates/99-hardening.conf

@@ -15,4 +15,18 @@
   </LimitExcept>
 </Location>
 
+<Directory />
+    Options -Indexes -FollowSymLinks
+    AllowOverride None
+</Directory>
+
+<Directory /var/www/>
+    Options -Indexes -FollowSymLinks
+    AllowOverride None
+</Directory>
+
 TraceEnable {{ traceenable }}
+ServerTokens {{ servertokens }}
+
+SSLHonorCipherOrder {{ honor_cipher_order }}
+SSLCipherSuite {{ cipher_suite }}

hooks/charmhelpers/contrib/hardening/audits/__init__.py

@@ -49,13 +49,6 @@ class BaseAudit(object):  # NO-QA
 
         # Invoke the callback if there is one.
         if hasattr(self.unless, '__call__'):
-            results = self.unless()
+            return not self.unless()
-            if results:
-                return False
-            else:
-                return True
 
-        if self.unless:
+        return not self.unless
-            return False
-        else:
-            return True

hooks/charmhelpers/contrib/hardening/defaults/apache.yaml

@@ -11,3 +11,6 @@ hardening:
     traceenable: 'off'
     allowed_http_methods: "GET POST"
     modules_to_disable: [ cgi, cgid ]
+    servertokens: 'Prod'
+    honor_cipher_order: 'on'
+    cipher_suite: 'ALL:+MEDIUM:+HIGH:!LOW:!MD5:!RC4:!eNULL:!aNULL:!3DES'

hooks/charmhelpers/contrib/hardening/defaults/apache.yaml.schema

@@ -7,3 +7,6 @@ common:
 hardening:
     allowed_http_methods:
     modules_to_disable:
+    servertokens:
+    honor_cipher_order:
+    cipher_suite:

hooks/charmhelpers/contrib/hardening/defaults/os.yaml

@@ -58,6 +58,7 @@ security:
         rsync
     kernel_enable_module_loading: True  # (type:boolean)
     kernel_enable_core_dump: False  # (type:boolean)
+    ssh_tmout: 300
 
 sysctl:
     kernel_secure_sysrq: 244  # 4 + 16 + 32 + 64 + 128

hooks/charmhelpers/contrib/hardening/defaults/os.yaml.schema

@@ -34,6 +34,7 @@ security:
     packages_list:
     kernel_enable_module_loading:
     kernel_enable_core_dump:
+    ssh_tmout:
 sysctl:
     kernel_secure_sysrq:
     kernel_enable_sysrq:

hooks/charmhelpers/contrib/hardening/host/checks/profile.py

@@ -25,7 +25,6 @@ def get_audits():
     audits = []
 
     settings = utils.get_settings('os')
-
     # If core dumps are not enabled, then don't allow core dumps to be
     # created as they may contain sensitive information.
     if not settings['security']['kernel_enable_core_dump']:
@@ -33,11 +32,18 @@ def get_audits():
                                     ProfileContext(),
                                     template_dir=TEMPLATES_DIR,
                                     mode=0o0755, user='root', group='root'))
+    if settings['security']['ssh_tmout']:
+        audits.append(TemplatedFile('/etc/profile.d/99-hardening.sh',
+                                    ProfileContext(),
+                                    template_dir=TEMPLATES_DIR,
+                                    mode=0o0644, user='root', group='root'))
     return audits
 
 
 class ProfileContext(object):
 
     def __call__(self):
-        ctxt = {}
+        settings = utils.get_settings('os')
+        ctxt = {'ssh_tmout':
+                settings['security']['ssh_tmout']}
         return ctxt

hooks/charmhelpers/contrib/hardening/host/templates/99-hardening.sh

@@ -0,0 +1,5 @@
+TMOUT={{ tmout }}
+readonly TMOUT
+export TMOUT
+
+readonly HISTFILE

hooks/charmhelpers/contrib/hardening/ssh/checks/config.py

@@ -27,7 +27,10 @@ from charmhelpers.fetch import (
     apt_install,
     apt_update,
 )
-from charmhelpers.core.host import lsb_release
+from charmhelpers.core.host import (
+    lsb_release,
+    CompareHostReleases,
+)
 from charmhelpers.contrib.hardening.audits.file import (
     TemplatedFile,
     FileContentAudit,
@@ -68,7 +71,8 @@ class SSHConfigContext(object):
                    'weak': default + ',hmac-sha1'}
 
         # Use newer ciphers on Ubuntu Trusty and above
-        if lsb_release()['DISTRIB_CODENAME'].lower() >= 'trusty':
+        _release = lsb_release()['DISTRIB_CODENAME'].lower()
+        if CompareHostReleases(_release) >= 'trusty':
             log("Detected Ubuntu 14.04 or newer, using new macs", level=DEBUG)
             macs = macs_66
 
@@ -96,7 +100,8 @@ class SSHConfigContext(object):
                   'weak': weak}
 
         # Use newer kex on Ubuntu Trusty and above
-        if lsb_release()['DISTRIB_CODENAME'].lower() >= 'trusty':
+        _release = lsb_release()['DISTRIB_CODENAME'].lower()
+        if CompareHostReleases(_release) >= 'trusty':
             log('Detected Ubuntu 14.04 or newer, using new key exchange '
                 'algorithms', level=DEBUG)
             kex = kex_66
@@ -119,7 +124,8 @@ class SSHConfigContext(object):
                       'weak': default + ',aes256-cbc,aes192-cbc,aes128-cbc'}
 
         # Use newer ciphers on ubuntu Trusty and above
-        if lsb_release()['DISTRIB_CODENAME'].lower() >= 'trusty':
+        _release = lsb_release()['DISTRIB_CODENAME'].lower()
+        if CompareHostReleases(_release) >= 'trusty':
             log('Detected Ubuntu 14.04 or newer, using new ciphers',
                 level=DEBUG)
             cipher = ciphers_66
@@ -291,7 +297,8 @@ class SSHConfigFileContentAudit(FileContentAudit):
         self.fail_cases = []
         settings = utils.get_settings('ssh')
 
-        if lsb_release()['DISTRIB_CODENAME'].lower() >= 'trusty':
+        _release = lsb_release()['DISTRIB_CODENAME'].lower()
+        if CompareHostReleases(_release) >= 'trusty':
             if not settings['server']['weak_hmac']:
                 self.pass_cases.append(r'^MACs.+,hmac-ripemd160$')
             else:
@@ -364,7 +371,8 @@ class SSHDConfigFileContentAudit(FileContentAudit):
         self.fail_cases = []
         settings = utils.get_settings('ssh')
 
-        if lsb_release()['DISTRIB_CODENAME'].lower() >= 'trusty':
+        _release = lsb_release()['DISTRIB_CODENAME'].lower()
+        if CompareHostReleases(_release) >= 'trusty':
             if not settings['server']['weak_hmac']:
                 self.pass_cases.append(r'^MACs.+,hmac-ripemd160$')
             else:

hooks/charmhelpers/contrib/network/ip.py

@@ -31,6 +31,7 @@ from charmhelpers.core.hookenv import (
 
 from charmhelpers.core.host import (
     lsb_release,
+    CompareHostReleases,
 )
 
 try:
@@ -67,6 +68,24 @@ def no_ip_found_error_out(network):
     raise ValueError(errmsg)
 
 
+def _get_ipv6_network_from_address(address):
+    """Get an netaddr.IPNetwork for the given IPv6 address
+    :param address: a dict as returned by netifaces.ifaddresses
+    :returns netaddr.IPNetwork: None if the address is a link local or loopback
+    address
+    """
+    if address['addr'].startswith('fe80') or address['addr'] == "::1":
+        return None
+
+    prefix = address['netmask'].split("/")
+    if len(prefix) > 1:
+        netmask = prefix[1]
+    else:
+        netmask = address['netmask']
+    return netaddr.IPNetwork("%s/%s" % (address['addr'],
+                                        netmask))
+
+
 def get_address_in_network(network, fallback=None, fatal=False):
     """Get an IPv4 or IPv6 address within the network from the host.
 
@@ -100,11 +119,9 @@ def get_address_in_network(network, fallback=None, fatal=False):
 
             if network.version == 6 and netifaces.AF_INET6 in addresses:
                 for addr in addresses[netifaces.AF_INET6]:
-                    if not addr['addr'].startswith('fe80'):
+                    cidr = _get_ipv6_network_from_address(addr)
-                        cidr = netaddr.IPNetwork("%s/%s" % (addr['addr'],
+                    if cidr and cidr in network:
-                                                            addr['netmask']))
+                        return str(cidr.ip)
-                        if cidr in network:
-                            return str(cidr.ip)
 
     if fallback is not None:
         return fallback
@@ -180,18 +197,18 @@ def _get_for_address(address, key):
 
         if address.version == 6 and netifaces.AF_INET6 in addresses:
             for addr in addresses[netifaces.AF_INET6]:
-                if not addr['addr'].startswith('fe80'):
+                network = _get_ipv6_network_from_address(addr)
-                    network = netaddr.IPNetwork("%s/%s" % (addr['addr'],
+                if not network:
-                                                           addr['netmask']))
+                    continue
-                    cidr = network.cidr
-                    if address in cidr:
-                        if key == 'iface':
-                            return iface
-                        elif key == 'netmask' and cidr:
-                            return str(cidr).split('/')[1]
-                        else:
-                            return addr[key]
 
+                cidr = network.cidr
+                if address in cidr:
+                    if key == 'iface':
+                        return iface
+                    elif key == 'netmask' and cidr:
+                        return str(cidr).split('/')[1]
+                    else:
+                        return addr[key]
     return None
 
 
@@ -521,7 +538,8 @@ def port_has_listener(address, port):
 
 def assert_charm_supports_ipv6():
     """Check whether we are able to support charms ipv6."""
-    if lsb_release()['DISTRIB_CODENAME'].lower() < "trusty":
+    release = lsb_release()['DISTRIB_CODENAME'].lower()
+    if CompareHostReleases(release) < "trusty":
         raise Exception("IPv6 is not supported in the charms for Ubuntu "
                         "versions less than Trusty 14.04")
 

hooks/charmhelpers/contrib/openstack/amulet/utils.py

@@ -40,6 +40,7 @@ from charmhelpers.contrib.amulet.utils import (
     AmuletUtils
 )
 from charmhelpers.core.decorators import retry_on_exception
+from charmhelpers.core.host import CompareHostReleases
 
 DEBUG = logging.DEBUG
 ERROR = logging.ERROR
@@ -1255,7 +1256,7 @@ class OpenStackAmuletUtils(AmuletUtils):
         contents = self.file_contents_safe(sentry_unit, '/etc/memcached.conf',
                                            fatal=True)
         ubuntu_release, _ = self.run_cmd_unit(sentry_unit, 'lsb_release -cs')
-        if ubuntu_release <= 'trusty':
+        if CompareHostReleases(ubuntu_release) <= 'trusty':
             memcache_listen_addr = 'ip6-localhost'
         else:
             memcache_listen_addr = '::1'

hooks/charmhelpers/contrib/openstack/context.py

@@ -59,6 +59,7 @@ from charmhelpers.core.host import (
     write_file,
     pwgen,
     lsb_release,
+    CompareHostReleases,
 )
 from charmhelpers.contrib.hahelpers.cluster import (
     determine_apache_port,
@@ -155,7 +156,8 @@ class OSContextGenerator(object):
 
         if self.missing_data:
             self.complete = False
-            log('Missing required data: %s' % ' '.join(self.missing_data), level=INFO)
+            log('Missing required data: %s' % ' '.join(self.missing_data),
+                level=INFO)
         else:
             self.complete = True
         return self.complete
@@ -213,8 +215,9 @@ class SharedDBContext(OSContextGenerator):
                 hostname_key = "{}_hostname".format(self.relation_prefix)
             else:
                 hostname_key = "hostname"
-            access_hostname = get_address_in_network(access_network,
+            access_hostname = get_address_in_network(
-                                                     unit_get('private-address'))
+                access_network,
+                unit_get('private-address'))
             set_hostname = relation_get(attribute=hostname_key,
                                         unit=local_unit())
             if set_hostname != access_hostname:
@@ -308,7 +311,10 @@ def db_ssl(rdata, ctxt, ssl_dir):
 
 class IdentityServiceContext(OSContextGenerator):
 
-    def __init__(self, service=None, service_user=None, rel_name='identity-service'):
+    def __init__(self,
+                 service=None,
+                 service_user=None,
+                 rel_name='identity-service'):
         self.service = service
         self.service_user = service_user
         self.rel_name = rel_name
@@ -457,19 +463,17 @@ class AMQPContext(OSContextGenerator):
                     host = format_ipv6_addr(host) or host
                     rabbitmq_hosts.append(host)
 
-                ctxt['rabbitmq_hosts'] = ','.join(sorted(rabbitmq_hosts))
+                rabbitmq_hosts = sorted(rabbitmq_hosts)
+                ctxt['rabbitmq_hosts'] = ','.join(rabbitmq_hosts)
                 transport_hosts = rabbitmq_hosts
 
             if transport_hosts:
-                transport_url_hosts = ''
+                transport_url_hosts = ','.join([
-                for host in transport_hosts:
+                    "{}:{}@{}:{}".format(ctxt['rabbitmq_user'],
-                    if transport_url_hosts:
+                                         ctxt['rabbitmq_password'],
-                        format_string = ",{}:{}@{}:{}"
+                                         host_,
-                    else:
+                                         rabbitmq_port)
-                        format_string = "{}:{}@{}:{}"
+                    for host_ in transport_hosts])
-                    transport_url_hosts += format_string.format(
-                        ctxt['rabbitmq_user'], ctxt['rabbitmq_password'],
-                        host, rabbitmq_port)
                 ctxt['transport_url'] = "rabbit://{}/{}".format(
                     transport_url_hosts, vhost)
 
@@ -1601,7 +1605,8 @@ class MemcacheContext(OSContextGenerator):
         if ctxt['use_memcache']:
             # Trusty version of memcached does not support ::1 as a listen
             # address so use host file entry instead
-            if lsb_release()['DISTRIB_CODENAME'].lower() > 'trusty':
+            release = lsb_release()['DISTRIB_CODENAME'].lower()
+            if CompareHostReleases(release) > 'trusty':
                 ctxt['memcache_server'] = '::1'
             else:
                 ctxt['memcache_server'] = 'ip6-localhost'

hooks/charmhelpers/contrib/openstack/neutron.py

@@ -23,7 +23,10 @@ from charmhelpers.core.hookenv import (
     ERROR,
 )
 
-from charmhelpers.contrib.openstack.utils import os_release
+from charmhelpers.contrib.openstack.utils import (
+    os_release,
+    CompareOpenStackReleases,
+)
 
 
 def headers_package():
@@ -198,7 +201,8 @@ def neutron_plugins():
         },
         'plumgrid': {
             'config': '/etc/neutron/plugins/plumgrid/plumgrid.ini',
-            'driver': 'neutron.plugins.plumgrid.plumgrid_plugin.plumgrid_plugin.NeutronPluginPLUMgridV2',
+            'driver': ('neutron.plugins.plumgrid.plumgrid_plugin'
+                       '.plumgrid_plugin.NeutronPluginPLUMgridV2'),
             'contexts': [
                 context.SharedDBContext(user=config('database-user'),
                                         database=config('database'),
@@ -225,7 +229,7 @@ def neutron_plugins():
             'server_services': ['neutron-server']
         }
     }
-    if release >= 'icehouse':
+    if CompareOpenStackReleases(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'
@@ -233,10 +237,10 @@ def neutron_plugins():
                                              'neutron-plugin-ml2']
         # NOTE: patch in vmware renames nvp->nsx for icehouse onwards
         plugins['nvp'] = plugins['nsx']
-    if release >= 'kilo':
+    if CompareOpenStackReleases(release) >= 'kilo':
         plugins['midonet']['driver'] = (
             'neutron.plugins.midonet.plugin.MidonetPluginV2')
-    if release >= 'liberty':
+    if CompareOpenStackReleases(release) >= 'liberty':
         plugins['midonet']['driver'] = (
             'midonet.neutron.plugin_v1.MidonetPluginV2')
         plugins['midonet']['server_packages'].remove(
@@ -244,10 +248,11 @@ def neutron_plugins():
         plugins['midonet']['server_packages'].append(
             'python-networking-midonet')
         plugins['plumgrid']['driver'] = (
-            'networking_plumgrid.neutron.plugins.plugin.NeutronPluginPLUMgridV2')
+            'networking_plumgrid.neutron.plugins'
+            '.plugin.NeutronPluginPLUMgridV2')
         plugins['plumgrid']['server_packages'].remove(
             'neutron-plugin-plumgrid')
-    if release >= 'mitaka':
+    if CompareOpenStackReleases(release) >= 'mitaka':
         plugins['nsx']['server_packages'].remove('neutron-plugin-vmware')
         plugins['nsx']['server_packages'].append('python-vmware-nsx')
         plugins['nsx']['config'] = '/etc/neutron/nsx.ini'

hooks/charmhelpers/contrib/openstack/utils.py

@@ -33,9 +33,7 @@ import yaml
 
 from charmhelpers.contrib.network import ip
 
-from charmhelpers.core import (
+from charmhelpers.core import unitdata
-    unitdata,
-)
 
 from charmhelpers.core.hookenv import (
     action_fail,
@@ -55,6 +53,8 @@ from charmhelpers.core.hookenv import (
     application_version_set,
 )
 
+from charmhelpers.core.strutils import BasicStringComparator
+
 from charmhelpers.contrib.storage.linux.lvm import (
     deactivate_lvm_volume_group,
     is_lvm_physical_volume,
@@ -97,6 +97,22 @@ CLOUD_ARCHIVE_KEY_ID = '5EDB1B62EC4926EA'
 DISTRO_PROPOSED = ('deb http://archive.ubuntu.com/ubuntu/ %s-proposed '
                    'restricted main multiverse universe')
 
+OPENSTACK_RELEASES = (
+    'diablo',
+    'essex',
+    'folsom',
+    'grizzly',
+    'havana',
+    'icehouse',
+    'juno',
+    'kilo',
+    'liberty',
+    'mitaka',
+    'newton',
+    'ocata',
+    'pike',
+)
+
 UBUNTU_OPENSTACK_RELEASE = OrderedDict([
     ('oneiric', 'diablo'),
     ('precise', 'essex'),
@@ -238,6 +254,17 @@ GIT_DEFAULT_BRANCHES = {
 DEFAULT_LOOPBACK_SIZE = '5G'
 
 
+class CompareOpenStackReleases(BasicStringComparator):
+    """Provide comparisons of OpenStack releases.
+
+    Use in the form of
+
+    if CompareOpenStackReleases(release) > 'mitaka':
+        # do something with mitaka
+    """
+    _list = OPENSTACK_RELEASES
+
+
 def error_out(msg):
     juju_log("FATAL ERROR: %s" % msg, level='ERROR')
     sys.exit(1)
@@ -1066,7 +1093,8 @@ def git_generate_systemd_init_files(templates_dir):
 
             shutil.copyfile(init_in_source, init_source)
             with open(init_source, 'a') as outfile:
-                template = '/usr/share/openstack-pkg-tools/init-script-template'
+                template = ('/usr/share/openstack-pkg-tools/'
+                            'init-script-template')
                 with open(template) as infile:
                     outfile.write('\n\n{}'.format(infile.read()))
 
@@ -1971,9 +1999,7 @@ def enable_memcache(source=None, release=None, package=None):
     if not _release:
         _release = get_os_codename_install_source(source)
 
-    # TODO: this should be changed to a numeric comparison using a known list
+    return CompareOpenStackReleases(_release) >= 'mitaka'
-    # of releases and comparing by index.
-    return _release >= 'mitaka'
 
 
 def token_cache_pkgs(source=None, release=None):

hooks/charmhelpers/core/host.py

@@ -45,6 +45,7 @@ if __platform__ == "ubuntu":
         add_new_group,
         lsb_release,
         cmp_pkgrevno,
+        CompareHostReleases,
     )  # flake8: noqa -- ignore F401 for this import
 elif __platform__ == "centos":
     from charmhelpers.core.host_factory.centos import (
@@ -52,6 +53,7 @@ elif __platform__ == "centos":
         add_new_group,
         lsb_release,
         cmp_pkgrevno,
+        CompareHostReleases,
     )  # flake8: noqa -- ignore F401 for this import
 
 UPDATEDB_PATH = '/etc/updatedb.conf'

hooks/charmhelpers/core/host_factory/centos.py

@@ -2,6 +2,22 @@ import subprocess
 import yum
 import os
 
+from charmhelpers.core.strutils import BasicStringComparator
+
+
+class CompareHostReleases(BasicStringComparator):
+    """Provide comparisons of Host releases.
+
+    Use in the form of
+
+    if CompareHostReleases(release) > 'trusty':
+        # do something with mitaka
+    """
+
+    def __init__(self, item):
+        raise NotImplementedError(
+            "CompareHostReleases() is not implemented for CentOS")
+
 
 def service_available(service_name):
     # """Determine whether a system service is available."""

hooks/charmhelpers/core/host_factory/ubuntu.py

@@ -1,5 +1,37 @@
 import subprocess
 
+from charmhelpers.core.strutils import BasicStringComparator
+
+
+UBUNTU_RELEASES = (
+    'lucid',
+    'maverick',
+    'natty',
+    'oneiric',
+    'precise',
+    'quantal',
+    'raring',
+    'saucy',
+    'trusty',
+    'utopic',
+    'vivid',
+    'wily',
+    'xenial',
+    'yakkety',
+    'zesty',
+)
+
+
+class CompareHostReleases(BasicStringComparator):
+    """Provide comparisons of Ubuntu releases.
+
+    Use in the form of
+
+    if CompareHostReleases(release) > 'trusty':
+        # do something with mitaka
+    """
+    _list = UBUNTU_RELEASES
+
 
 def service_available(service_name):
     """Determine whether a system service is available"""

hooks/charmhelpers/core/strutils.py

@@ -68,3 +68,56 @@ def bytes_from_string(value):
         msg = "Unable to interpret string value '%s' as bytes" % (value)
         raise ValueError(msg)
     return int(matches.group(1)) * (1024 ** BYTE_POWER[matches.group(2)])
+
+
+class BasicStringComparator(object):
+    """Provides a class that will compare strings from an iterator type object.
+    Used to provide > and < comparisons on strings that may not necessarily be
+    alphanumerically ordered.  e.g. OpenStack or Ubuntu releases AFTER the
+    z-wrap.
+    """
+
+    _list = None
+
+    def __init__(self, item):
+        if self._list is None:
+            raise Exception("Must define the _list in the class definition!")
+        try:
+            self.index = self._list.index(item)
+        except Exception:
+            raise KeyError("Item '{}' is not in list '{}'"
+                           .format(item, self._list))
+
+    def __eq__(self, other):
+        assert isinstance(other, str) or isinstance(other, self.__class__)
+        return self.index == self._list.index(other)
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __lt__(self, other):
+        assert isinstance(other, str) or isinstance(other, self.__class__)
+        return self.index < self._list.index(other)
+
+    def __ge__(self, other):
+        return not self.__lt__(other)
+
+    def __gt__(self, other):
+        assert isinstance(other, str) or isinstance(other, self.__class__)
+        return self.index > self._list.index(other)
+
+    def __le__(self, other):
+        return not self.__gt__(other)
+
+    def __str__(self):
+        """Always give back the item at the index so it can be used in
+        comparisons like:
+
+        s_mitaka = CompareOpenStack('mitaka')
+        s_newton = CompareOpenstack('newton')
+
+        assert s_newton > s_mitaka
+
+        @returns: <string>
+        """
+        return self._list[self.index]

hooks/neutron_api_context.py

@@ -30,6 +30,7 @@ from charmhelpers.contrib.hahelpers.cluster import (
 )
 from charmhelpers.contrib.openstack.utils import (
     os_release,
+    CompareOpenStackReleases,
 )
 
 VLAN = 'vlan'
@@ -87,7 +88,7 @@ def get_tenant_network_types():
 
 def get_l3ha():
     if config('enable-l3ha'):
-        if os_release('neutron-server') < 'juno':
+        if CompareOpenStackReleases(os_release('neutron-server')) < 'juno':
             log('Disabling L3 HA, enable-l3ha is not valid before Juno')
             return False
         if get_l2population():
@@ -100,10 +101,11 @@ def get_l3ha():
 
 def get_dvr():
     if config('enable-dvr'):
-        if os_release('neutron-server') < 'juno':
+        release = os_release('neutron-server')
+        if CompareOpenStackReleases(release) < 'juno':
             log('Disabling DVR, enable-dvr is not valid before Juno')
             return False
-        if os_release('neutron-server') == 'juno':
+        if CompareOpenStackReleases(release) == 'juno':
             if VXLAN not in config('overlay-network-type').split():
                 log('Disabling DVR, enable-dvr requires the use of the vxlan '
                     'overlay network for OpenStack Juno')
@@ -240,6 +242,7 @@ class NeutronCCContext(context.NeutronContext):
         ctxt['overlay_network_type'] = self.neutron_overlay_network_type
         ctxt['external_network'] = config('neutron-external-network')
         release = os_release('neutron-server')
+        cmp_release = CompareOpenStackReleases(release)
         if config('neutron-plugin') in ['vsp']:
             _config = config()
             for k, v in _config.iteritems():
@@ -249,7 +252,7 @@ class NeutronCCContext(context.NeutronContext):
                 for unit in related_units(rid):
                     rdata = relation_get(rid=rid, unit=unit)
                     vsd_ip = rdata.get('vsd-ip-address')
-                    if release >= 'kilo':
+                    if cmp_release >= 'kilo':
                         cms_id_value = rdata.get('nuage-cms-id')
                         log('relation data:cms_id required for'
                             ' nuage plugin: {}'.format(cms_id_value))
@@ -297,12 +300,12 @@ class NeutronCCContext(context.NeutronContext):
         ctxt['enable_ml2_port_security'] = config('enable-ml2-port-security')
         ctxt['enable_sriov'] = config('enable-sriov')
 
-        if release == 'kilo' or release >= 'mitaka':
+        if cmp_release == 'kilo' or cmp_release >= 'mitaka':
             ctxt['enable_hyperv'] = True
         else:
             ctxt['enable_hyperv'] = False
 
-        if release >= 'mitaka':
+        if cmp_release >= 'mitaka':
             if config('global-physnet-mtu'):
                 ctxt['global_physnet_mtu'] = config('global-physnet-mtu')
                 if config('path-mtu'):

hooks/neutron_api_hooks.py

@@ -60,6 +60,7 @@ from charmhelpers.contrib.openstack.utils import (
     sync_db_with_multi_ipv6_addresses,
     is_unit_paused_set,
     pausable_restart_on_change as restart_on_change,
+    CompareOpenStackReleases,
 )
 
 from neutron_api_utils import (
@@ -132,7 +133,7 @@ CONFIGS = register_configs()
 
 
 def conditional_neutron_migration():
-    if os_release('neutron-server') <= 'icehouse':
+    if CompareOpenStackReleases(os_release('neutron-server')) <= 'icehouse':
         log('Not running neutron database migration as migrations are handled '
             'by the neutron-server process.')
         return
@@ -204,7 +205,7 @@ def install():
 @hooks.hook('vsd-rest-api-relation-joined')
 @restart_on_change(restart_map(), stopstart=True)
 def relation_set_nuage_cms_name(rid=None):
-    if os_release('neutron-server') >= 'kilo':
+    if CompareOpenStackReleases(os_release('neutron-server')) >= 'kilo':
         if config('vsd-cms-name') is None:
             e = "Neutron Api hook failed as vsd-cms-name" \
                 " is not specified"
@@ -224,7 +225,7 @@ def vsd_changed(relation_id=None, remote_unit=None):
         if not vsd_ip_address:
             return
         vsd_address = '{}:8443'.format(vsd_ip_address)
-        if os_release('neutron-server') >= 'kilo':
+        if CompareOpenStackReleases(os_release('neutron-server')) >= 'kilo':
             vsd_cms_id = relation_get('nuage-cms-id')
             log("nuage-vsd-api-relation-changed : cms_id:{}"
                 .format(vsd_cms_id))

hooks/neutron_api_utils.py

@@ -44,6 +44,7 @@ from charmhelpers.contrib.openstack.utils import (
     os_application_version_set,
     token_cache_pkgs,
     enable_memcache,
+    CompareOpenStackReleases,
 )
 
 from charmhelpers.contrib.python.packages import (
@@ -69,6 +70,7 @@ from charmhelpers.core.host import (
     adduser,
     add_group,
     add_user_to_group,
+    CompareHostReleases,
     mkdir,
     service_stop,
     service_start,
@@ -316,10 +318,10 @@ def determine_packages(source=None):
 
     release = get_os_codename_install_source(source)
 
-    if release >= 'kilo':
+    if CompareOpenStackReleases(release) >= 'kilo':
         packages.extend(KILO_PACKAGES)
 
-    if release == 'kilo' or release >= 'mitaka':
+    if release == 'kilo' or CompareOpenStackReleases(release) >= 'mitaka':
         packages.append('python-networking-hyperv')
 
     if config('neutron-plugin') == 'vsp':
@@ -333,7 +335,7 @@ def determine_packages(source=None):
         for p in GIT_PACKAGE_BLACKLIST:
             if p in packages:
                 packages.remove(p)
-        if release >= 'kilo':
+        if CompareOpenStackReleases(release) >= 'kilo':
             for p in GIT_PACKAGE_BLACKLIST_KILO:
                 packages.remove(p)
 
@@ -361,7 +363,7 @@ def resource_map(release=None):
     release = release or os_release('neutron-common')
 
     resource_map = deepcopy(BASE_RESOURCE_MAP)
-    if release >= 'liberty':
+    if CompareOpenStackReleases(release) >= 'liberty':
         resource_map.update(LIBERTY_RESOURCE_MAP)
 
     if os.path.exists('/etc/apache2/conf-available'):
@@ -466,7 +468,7 @@ def do_openstack_upgrade(configs):
     # Before kilo it's nova-cloud-controllers job
     if is_elected_leader(CLUSTER_RES):
         # Stamping seems broken and unnecessary in liberty (Bug #1536675)
-        if os_release('neutron-common') < 'liberty':
+        if CompareOpenStackReleases(os_release('neutron-common')) < 'liberty':
             stamp_neutron_database(cur_os_rel)
         migrate_neutron_database()
 
@@ -546,13 +548,15 @@ def get_topics():
 
 def setup_ipv6():
     ubuntu_rel = lsb_release()['DISTRIB_CODENAME'].lower()
-    if ubuntu_rel < "trusty":
+    if CompareHostReleases(ubuntu_rel) < "trusty":
         raise Exception("IPv6 is not supported in the charms for Ubuntu "
                         "versions less than Trusty 14.04")
 
     # Need haproxy >= 1.5.3 for ipv6 so for Trusty if we are <= Kilo we need to
     # use trusty-backports otherwise we can use the UCA.
-    if ubuntu_rel == 'trusty' and os_release('neutron-server') < 'liberty':
+    this_os_release = os_release('neutron-server')
+    if (ubuntu_rel == 'trusty' and
+            CompareOpenStackReleases(this_os_release) < 'liberty'):
         add_source('deb http://archive.ubuntu.com/ubuntu trusty-backports '
                    'main')
         apt_update()

tests/charmhelpers/contrib/openstack/amulet/utils.py

@@ -40,6 +40,7 @@ from charmhelpers.contrib.amulet.utils import (
     AmuletUtils
 )
 from charmhelpers.core.decorators import retry_on_exception
+from charmhelpers.core.host import CompareHostReleases
 
 DEBUG = logging.DEBUG
 ERROR = logging.ERROR
@@ -1255,7 +1256,7 @@ class OpenStackAmuletUtils(AmuletUtils):
         contents = self.file_contents_safe(sentry_unit, '/etc/memcached.conf',
                                            fatal=True)
         ubuntu_release, _ = self.run_cmd_unit(sentry_unit, 'lsb_release -cs')
-        if ubuntu_release <= 'trusty':
+        if CompareHostReleases(ubuntu_release) <= 'trusty':
             memcache_listen_addr = 'ip6-localhost'
         else:
             memcache_listen_addr = '::1'

tests/charmhelpers/core/host.py

@@ -45,6 +45,7 @@ if __platform__ == "ubuntu":
         add_new_group,
         lsb_release,
         cmp_pkgrevno,
+        CompareHostReleases,
     )  # flake8: noqa -- ignore F401 for this import
 elif __platform__ == "centos":
     from charmhelpers.core.host_factory.centos import (
@@ -52,6 +53,7 @@ elif __platform__ == "centos":
         add_new_group,
         lsb_release,
         cmp_pkgrevno,
+        CompareHostReleases,
     )  # flake8: noqa -- ignore F401 for this import
 
 UPDATEDB_PATH = '/etc/updatedb.conf'

tests/charmhelpers/core/host_factory/centos.py

@@ -2,6 +2,22 @@ import subprocess
 import yum
 import os
 
+from charmhelpers.core.strutils import BasicStringComparator
+
+
+class CompareHostReleases(BasicStringComparator):
+    """Provide comparisons of Host releases.
+
+    Use in the form of
+
+    if CompareHostReleases(release) > 'trusty':
+        # do something with mitaka
+    """
+
+    def __init__(self, item):
+        raise NotImplementedError(
+            "CompareHostReleases() is not implemented for CentOS")
+
 
 def service_available(service_name):
     # """Determine whether a system service is available."""

tests/charmhelpers/core/host_factory/ubuntu.py

@@ -1,5 +1,37 @@
 import subprocess
 
+from charmhelpers.core.strutils import BasicStringComparator
+
+
+UBUNTU_RELEASES = (
+    'lucid',
+    'maverick',
+    'natty',
+    'oneiric',
+    'precise',
+    'quantal',
+    'raring',
+    'saucy',
+    'trusty',
+    'utopic',
+    'vivid',
+    'wily',
+    'xenial',
+    'yakkety',
+    'zesty',
+)
+
+
+class CompareHostReleases(BasicStringComparator):
+    """Provide comparisons of Ubuntu releases.
+
+    Use in the form of
+
+    if CompareHostReleases(release) > 'trusty':
+        # do something with mitaka
+    """
+    _list = UBUNTU_RELEASES
+
 
 def service_available(service_name):
     """Determine whether a system service is available"""

tests/charmhelpers/core/strutils.py

@@ -68,3 +68,56 @@ def bytes_from_string(value):
         msg = "Unable to interpret string value '%s' as bytes" % (value)
         raise ValueError(msg)
     return int(matches.group(1)) * (1024 ** BYTE_POWER[matches.group(2)])
+
+
+class BasicStringComparator(object):
+    """Provides a class that will compare strings from an iterator type object.
+    Used to provide > and < comparisons on strings that may not necessarily be
+    alphanumerically ordered.  e.g. OpenStack or Ubuntu releases AFTER the
+    z-wrap.
+    """
+
+    _list = None
+
+    def __init__(self, item):
+        if self._list is None:
+            raise Exception("Must define the _list in the class definition!")
+        try:
+            self.index = self._list.index(item)
+        except Exception:
+            raise KeyError("Item '{}' is not in list '{}'"
+                           .format(item, self._list))
+
+    def __eq__(self, other):
+        assert isinstance(other, str) or isinstance(other, self.__class__)
+        return self.index == self._list.index(other)
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __lt__(self, other):
+        assert isinstance(other, str) or isinstance(other, self.__class__)
+        return self.index < self._list.index(other)
+
+    def __ge__(self, other):
+        return not self.__lt__(other)
+
+    def __gt__(self, other):
+        assert isinstance(other, str) or isinstance(other, self.__class__)
+        return self.index > self._list.index(other)
+
+    def __le__(self, other):
+        return not self.__gt__(other)
+
+    def __str__(self):
+        """Always give back the item at the index so it can be used in
+        comparisons like:
+
+        s_mitaka = CompareOpenStack('mitaka')
+        s_newton = CompareOpenstack('newton')
+
+        assert s_newton > s_mitaka
+
+        @returns: <string>
+        """
+        return self._list[self.index]

tests/charmhelpers/osplatform.py

@@ -0,0 +1,25 @@
+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.
+    """
+    # linux_distribution is deprecated and will be removed in Python 3.7
+    # Warings *not* disabled, as we certainly need to fix this.
+    tuple_platform = platform.linux_distribution()
+    current_platform = tuple_platform[0]
+    if "Ubuntu" in current_platform:
+        return "ubuntu"
+    elif "CentOS" in current_platform:
+        return "centos"
+    elif "debian" in current_platform:
+        # Stock Python does not detect Ubuntu and instead returns debian.
+        # Or at least it does in some build environments like Travis CI
+        return "ubuntu"
+    else:
+        raise RuntimeError("This module is not supported on {}."
+                           .format(current_platform))

tox.ini

@@ -14,7 +14,7 @@ install_command =
   pip install --allow-unverified python-apt {opts} {packages}
 commands = ostestr {posargs}
 whitelist_externals = juju
-passenv = HOME TERM AMULET_*
+passenv = HOME TERM AMULET_*  CS_API_*
 
 [testenv:py27]
 basepython = python2.7

unit_tests/test_neutron_api_context.py

@@ -386,6 +386,7 @@ class NeutronCCContextTest(CharmTestCase):
             'enable_hyperv': False
         }
         napi_ctxt = context.NeutronCCContext()
+        self.os_release.return_value = 'havana'
         with patch.object(napi_ctxt, '_ensure_packages'):
             self.assertEquals(ctxt_data, napi_ctxt())
 
@@ -427,6 +428,7 @@ class NeutronCCContextTest(CharmTestCase):
             'enable_hyperv': False
         }
         napi_ctxt = context.NeutronCCContext()
+        self.os_release.return_value = 'havana'
         with patch.object(napi_ctxt, '_ensure_packages'):
             self.assertEquals(ctxt_data, napi_ctxt())
 
@@ -509,6 +511,7 @@ class NeutronCCContextTest(CharmTestCase):
             'enable_hyperv': False
         }
         napi_ctxt = context.NeutronCCContext()
+        self.os_release.return_value = 'havana'
         with patch.object(napi_ctxt, '_ensure_packages'):
             self.assertEquals(ctxt_data, napi_ctxt())
 
@@ -527,6 +530,7 @@ class NeutronCCContextTest(CharmTestCase):
     def test_neutroncc_context_api_rel(self, _import, plugin, nm):
         nova_url = 'http://127.0.0.10'
         plugin.return_value = None
+        self.os_release.return_value = 'havana'
         self.related_units.return_value = ['unit1']
         self.relation_ids.return_value = ['rid2']
         self.test_relation.set({'nova_url': nova_url,
@@ -553,6 +557,7 @@ class NeutronCCContextTest(CharmTestCase):
     @patch('__builtin__.__import__')
     def test_neutroncc_context_nsx(self, _import, plugin, nm):
         plugin.return_value = 'nsx'
+        self.os_release.return_value = 'havana'
         self.related_units.return_value = []
         self.test_config.set('neutron-plugin', 'nsx')
         napi_ctxt = context.NeutronCCContext()()
@@ -572,6 +577,7 @@ class NeutronCCContextTest(CharmTestCase):
     @patch('__builtin__.__import__')
     def test_neutroncc_context_nuage(self, _import, plugin, nm):
         plugin.return_value = 'vsp'
+        self.os_release.return_value = 'havana'
         self.related_units.return_value = ['vsdunit1']
         self.relation_ids.return_value = ['vsdrid2']
         self.test_config.set('neutron-plugin', 'vsp')

unit_tests/test_neutron_api_utils.py

@@ -121,6 +121,8 @@ class TestNeutronAPIUtils(CharmTestCase):
 
     @patch.object(nutils, 'git_install_requested')
     def test_determine_packages(self, git_requested):
+        self.os_release.return_value = 'havana'
+        self.get_os_codename_install_source.return_value = 'havana'
         git_requested.return_value = False
         pkg_list = nutils.determine_packages()
         expect = deepcopy(nutils.BASE_PACKAGES)
@@ -129,6 +131,7 @@ class TestNeutronAPIUtils(CharmTestCase):
 
     @patch.object(nutils, 'git_install_requested')
     def test_determine_vsp_packages(self, git_requested):
+        self.os_release.return_value = 'havana'
         git_requested.return_value = False
         self.test_config.set('nuage-packages',
                              'python-nuagenetlib nuage-neutron')
@@ -142,6 +145,7 @@ class TestNeutronAPIUtils(CharmTestCase):
 
     @patch.object(nutils, 'git_install_requested')
     def test_determine_packages_kilo(self, git_requested):
+        self.os_release.return_value = 'havana'
         git_requested.return_value = False
         self.get_os_codename_install_source.return_value = 'kilo'
         pkg_list = nutils.determine_packages()
@@ -153,6 +157,8 @@ class TestNeutronAPIUtils(CharmTestCase):
 
     @patch.object(nutils, 'git_install_requested')
     def test_determine_packages_noplugin(self, git_requested):
+        self.os_release.return_value = 'havana'
+        self.get_os_codename_install_source.return_value = 'havana'
         git_requested.return_value = False
         self.test_config.set('manage-neutron-plugin-legacy-mode', False)
         pkg_list = nutils.determine_packages()
@@ -161,12 +167,14 @@ class TestNeutronAPIUtils(CharmTestCase):
         self.assertItemsEqual(pkg_list, expect)
 
     def test_determine_ports(self):
+        self.os_release.return_value = 'havana'
         port_list = nutils.determine_ports()
         self.assertItemsEqual(port_list, [9696])
 
     @patch.object(nutils, 'manage_plugin')
     @patch('os.path.exists')
     def test_resource_map(self, _path_exists, _manage_plugin):
+        self.os_release.return_value = 'havana'
         _path_exists.return_value = False
         _manage_plugin.return_value = True
         _map = nutils.resource_map()
@@ -191,6 +199,7 @@ class TestNeutronAPIUtils(CharmTestCase):
     @patch.object(nutils, 'manage_plugin')
     @patch('os.path.exists')
     def test_resource_map_apache24(self, _path_exists, _manage_plugin):
+        self.os_release.return_value = 'havana'
         _path_exists.return_value = True
         _manage_plugin.return_value = True
         _map = nutils.resource_map()
@@ -202,6 +211,7 @@ class TestNeutronAPIUtils(CharmTestCase):
     @patch.object(nutils, 'manage_plugin')
     @patch('os.path.exists')
     def test_resource_map_noplugin(self, _path_exists, _manage_plugin):
+        self.os_release.return_value = 'havana'
         _path_exists.return_value = True
         _manage_plugin.return_value = False
         _map = nutils.resource_map()
@@ -217,6 +227,7 @@ class TestNeutronAPIUtils(CharmTestCase):
 
     @patch('os.path.exists')
     def test_restart_map(self, mock_path_exists):
+        self.os_release.return_value = 'havana'
         mock_path_exists.return_value = False
         _restart_map = nutils.restart_map()
         ML2CONF = "/etc/neutron/plugins/ml2/ml2_conf.ini"
@@ -244,6 +255,7 @@ class TestNeutronAPIUtils(CharmTestCase):
 
     @patch('os.path.exists')
     def test_register_configs(self, mock_path_exists):
+        self.os_release.return_value = 'havana'
         mock_path_exists.return_value = False
 
         class _mock_OSConfigRenderer():