Fixed inability to deploy if security groups are disabled

Existing implementation of Neutron-based networking assumed that the
neutron's security groups are used to manage VM accessibility.
However there may exist environments with disabled security-group
extension in Neutron and thus relying on something else to restrict
the traffic. Murano could not operate in such environments since it
always was attempting to create resources of type
OS::Neutron::SecurityGroup and attach VMs' ports to this resource.

This is addressed by introducing a new subclass of
SecurityGroupManager - DummySecurityGroupManager, which actually does
nothing but silently ignores the calls to create security rules. This
new security manager is instantiated instead of
NeutronSecurityGroupManager for Neutron-based networks in cases if the
'security-group' extension is not present in Neutron's configuration.
If it is instantiated a warning message is reported to the end-user to
notify them that security requirements of the application were
ignored.

Change-Id: Ia3bc6c17f9ca0a4b8bf8c272481760a8c81b27b7
Closes-bug: #1593253

meta/io.murano/Classes/resources/NeutronNetworkBase.yaml

@@ -20,6 +20,11 @@ Name: NeutronNetworkBase
 Extends: Network
 
 Methods:
+  initialize:
+    Body:
+      - $._netExplorer: new(sys:NetworkExplorer, $this)
+      - $._securityGroupsEnabled: $._netExplorer.listNeutronExtensions().alias.contains('security-group')
+
   joinInstanceToNetwork:
     Arguments:
       - instance:
@@ -49,7 +54,7 @@ Methods:
                   - subnet: $subnetRef
                 replacement_policy: AUTO
 
-      - If: bool($securityGroupName)
+      - If: bool($securityGroupName) and $this._securityGroupsEnabled
         Then:
           - $template:
               resources:
@@ -107,4 +112,9 @@ Methods:
       - environment:
           Contract: $.class(std:Environment).notNull()
     Body:
-      - Return: new(sys:NeutronSecurityGroupManager, environment => $environment)
+      - If: $this._securityGroupsEnabled
+        Then:
+          - Return: new(sys:NeutronSecurityGroupManager, environment => $environment)
+        Else:
+          - $environment.reporter.report($this, "Warning! Security groups are disabled!")
+          - Return: new(sys:DummySecurityGroupManager, environment => $environment)

meta/io.murano/Classes/system/DummySecurityGroupManager.yaml

@@ -0,0 +1,23 @@
+#  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.
+
+Namespaces:
+  =: io.murano.system
+  std: io.murano
+
+Name: DummySecurityGroupManager
+Extends: SecurityGroupManager
+
+# This class actually adds nothing to the base SecurityGroupManager,
+# so a base class could be used instead. However, it's better to explicitly
+# declare this class and use it, since the base one is supposed to remain
+# "abstract" and never be instantiated.

meta/io.murano/manifest.yaml

@@ -67,6 +67,7 @@ Classes:
   io.murano.system.SecurityGroupManager: system/SecurityGroupManager.yaml
   io.murano.system.NeutronSecurityGroupManager: system/NeutronSecurityGroupManager.yaml
   io.murano.system.AwsSecurityGroupManager: system/AwsSecurityGroupManager.yaml
+  io.murano.system.DummySecurityGroupManager: system/DummySecurityGroupManager.yaml
   io.murano.system.MistralClient: system/MistralClient.yaml
 
   io.murano.test.TestFixture: test/TestFixture.yaml

murano/engine/system/net_explorer.py

@@ -191,3 +191,7 @@ class NetworkExplorer(object):
 
     def list_ports(self):
         return self._client.list_ports()['ports']
+
+    @session_local_storage.execution_session_memoize
+    def list_neutron_extensions(self):
+        return self._client.list_extensions()['extensions']

releasenotes/notes/no-neutron-sec-group-support-2d69082b7226d6c0.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - Murano is now able to deploy applications in the environments with disabled
+    Neutron Security Groups. Detection is based on the presence of
+    'security-group' Neutron extension.