Charmhelper sync for 20.02

Change-Id: I2abca60fd270dc0dd9750aab2b6a41efb63db7d5

charmhelpers/contrib/openstack/context.py

@@ -25,6 +25,10 @@ from subprocess import check_call, CalledProcessError
 
 import six
 
+from charmhelpers.contrib.openstack.audits.openstack_security_guide import (
+    _config_ini as config_ini
+)
+
 from charmhelpers.fetch import (
     apt_install,
     filter_installed_packages,
@@ -2244,3 +2248,151 @@ class HostInfoContext(OSContextGenerator):
                 self.use_fqdn_hint_cb() if self.use_fqdn_hint_cb else False)
         }
         return ctxt
+
+
+def validate_ovs_use_veth(*args, **kwargs):
+    """Validate OVS use veth setting for dhcp agents
+
+    The ovs_use_veth setting is considered immutable as it will break existing
+    deployments. Historically, we set ovs_use_veth=True in dhcp_agent.ini. It
+    turns out this is no longer necessary. Ideally, all new deployments would
+    have this set to False.
+
+    This function validates that the config value does not conflict with
+    previously deployed settings in dhcp_agent.ini.
+
+    See LP Bug#1831935 for details.
+
+    :returns: Status state and message
+    :rtype: Union[(None, None), (string, string)]
+    """
+    existing_ovs_use_veth = (
+        DHCPAgentContext.get_existing_ovs_use_veth())
+    config_ovs_use_veth = DHCPAgentContext.parse_ovs_use_veth()
+
+    # Check settings are set and not None
+    if existing_ovs_use_veth is not None and config_ovs_use_veth is not None:
+        # Check for mismatch between existing config ini and juju config
+        if existing_ovs_use_veth != config_ovs_use_veth:
+            # Stop the line to avoid breakage
+            msg = (
+                "The existing setting for dhcp_agent.ini ovs_use_veth, {}, "
+                "does not match the juju config setting, {}. This may lead to "
+                "VMs being unable to receive a DHCP IP. Either change the "
+                "juju config setting or dhcp agents may need to be recreated."
+                .format(existing_ovs_use_veth, config_ovs_use_veth))
+            log(msg, ERROR)
+            return (
+                "blocked",
+                "Mismatched existing and configured ovs-use-veth. See log.")
+
+    # Everything is OK
+    return None, None
+
+
+class DHCPAgentContext(OSContextGenerator):
+
+    def __call__(self):
+        """Return the DHCPAGentContext.
+
+        Return all DHCP Agent INI related configuration.
+        ovs unit is attached to (as a subordinate) and the 'dns_domain' from
+        the neutron-plugin-api relations (if one is set).
+
+        :returns: Dictionary context
+        :rtype: Dict
+        """
+
+        ctxt = {}
+        dnsmasq_flags = config('dnsmasq-flags')
+        if dnsmasq_flags:
+            ctxt['dnsmasq_flags'] = config_flags_parser(dnsmasq_flags)
+        ctxt['dns_servers'] = config('dns-servers')
+
+        neutron_api_settings = NeutronAPIContext()()
+
+        ctxt['debug'] = config('debug')
+        ctxt['instance_mtu'] = config('instance-mtu')
+        ctxt['ovs_use_veth'] = self.get_ovs_use_veth()
+
+        ctxt['enable_metadata_network'] = config('enable-metadata-network')
+        ctxt['enable_isolated_metadata'] = config('enable-isolated-metadata')
+
+        if neutron_api_settings.get('dns_domain'):
+            ctxt['dns_domain'] = neutron_api_settings.get('dns_domain')
+
+        # Override user supplied config for these plugins as these settings are
+        # mandatory
+        if config('plugin') in ['nvp', 'nsx', 'n1kv']:
+            ctxt['enable_metadata_network'] = True
+            ctxt['enable_isolated_metadata'] = True
+
+        return ctxt
+
+    @staticmethod
+    def get_existing_ovs_use_veth():
+        """Return existing ovs_use_veth setting from dhcp_agent.ini.
+
+        :returns: Boolean value of existing ovs_use_veth setting or None
+        :rtype: Optional[Bool]
+        """
+        DHCP_AGENT_INI = "/etc/neutron/dhcp_agent.ini"
+        existing_ovs_use_veth = None
+        # If there is a dhcp_agent.ini file read the current setting
+        if os.path.isfile(DHCP_AGENT_INI):
+            # config_ini does the right thing and returns None if the setting is
+            # commented.
+            existing_ovs_use_veth = (
+                config_ini(DHCP_AGENT_INI)["DEFAULT"].get("ovs_use_veth"))
+        # Convert to Bool if necessary
+        if isinstance(existing_ovs_use_veth, six.string_types):
+            return bool_from_string(existing_ovs_use_veth)
+        return existing_ovs_use_veth
+
+    @staticmethod
+    def parse_ovs_use_veth():
+        """Parse the ovs-use-veth config setting.
+
+        Parse the string config setting for ovs-use-veth and return a boolean
+        or None.
+
+        bool_from_string will raise a ValueError if the string is not falsy or
+        truthy.
+
+        :raises: ValueError for invalid input
+        :returns: Boolean value of ovs-use-veth or None
+        :rtype: Optional[Bool]
+        """
+        _config = config("ovs-use-veth")
+        # An unset parameter returns None. Just in case we will also check for
+        # an empty string: "". Ironically, (the problem we are trying to avoid)
+        # "False" returns True and "" returns False.
+        if _config is None or not _config:
+            # Return None
+            return
+        # bool_from_string handles many variations of true and false strings
+        # as well as upper and lowercases including:
+        # ['y', 'yes', 'true', 't', 'on', 'n', 'no', 'false', 'f', 'off']
+        return bool_from_string(_config)
+
+    def get_ovs_use_veth(self):
+        """Return correct ovs_use_veth setting for use in dhcp_agent.ini.
+
+        Get the right value from config or existing dhcp_agent.ini file.
+        Existing has precedence. Attempt to default to "False" without
+        disrupting existing deployments. Handle existing deployments and
+        upgrades safely. See LP Bug#1831935
+
+        :returns: Value to use for ovs_use_veth setting
+        :rtype: Bool
+        """
+        _existing = self.get_existing_ovs_use_veth()
+        if _existing is not None:
+            return _existing
+
+        _config = self.parse_ovs_use_veth()
+        if _config is None:
+            # New better default
+            return False
+        else:
+            return _config

charmhelpers/osplatform.py

@@ -20,6 +20,9 @@ def get_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"
+    elif "elementary" in current_platform:
+        # ElementaryOS fails to run tests locally without this.
+        return "ubuntu"
     else:
         raise RuntimeError("This module is not supported on {}."
                            .format(current_platform))