Remove stale security group rules

When a security group is deleted all security group rules which
reference it as 'remote_group_id' should be deleted.
As the contrail data model does not permit to easy found that rules,
that fix propose to hide that stale rules only when they are listed or
read.

[1] https://github.com/openstack/tempest/search?utf8=%E2%9C%93&q=test_security_group_rules_delete_when_peer_group_deleted&type=Code

Change-Id: I219f4127785ab300302f2b7454321de83770a4a9
Closes-Bug: #1591976

neutron_plugin_contrail/plugins/opencontrail/vnc_client/sgrule_res_handler.py

@@ -60,15 +60,16 @@ def _security_group_rule_vnc_to_neutron(self, sg_id, sg_rule,
             if addr.get_security_group() != 'any' and (
                     addr.get_security_group() != 'local'):
                 remote_sg = addr.get_security_group()
-                try:
-                    if remote_sg != ':'.join(sg_obj.get_fq_name()):
-                        remote_sg_obj = sg_handler.SecurityGroupHandler(
-                            self._vnc_lib).get_sg_obj(fq_name_str=remote_sg)
-                    else:
-                        remote_sg_obj = sg_obj
-                    remote_sg_uuid = remote_sg_obj.uuid
-                except vnc_exc.NoIdError:
-                    pass
+                if remote_sg != ':'.join(sg_obj.get_fq_name()):
+                    try:
+                        remote_sg_uuid = self._vnc_lib.fq_name_to_id(
+                            'security-group', remote_sg.split(':'))
+                    except vnc_exc.NoIdError:
+                        # Filter rule out as the remote security group does not
+                        # exist anymore
+                        return sgr_q_dict
+                else:
+                    remote_sg_uuid = sg_obj.uuid
 
         sgr_q_dict['id'] = sg_rule.get_rule_uuid()
         sgr_q_dict['tenant_id'] = self._project_id_vnc_to_neutron(
@@ -131,9 +132,11 @@ def resource_get(self, context, sgr_id, fields=None):
 
         sg_obj, sg_rule = self._security_group_rule_find(sgr_id, project_uuid)
         if sg_obj and sg_rule:
-            return self._security_group_rule_vnc_to_neutron(sg_obj.uuid,
-                                                            sg_rule, sg_obj,
-                                                            fields=fields)
+            sgr_info = self._security_group_rule_vnc_to_neutron(sg_obj.uuid,
+                                                                sg_rule, sg_obj,
+                                                                fields=fields)
+            if sgr_info:
+                return sgr_info
 
         self._raise_contrail_exception('SecurityGroupRuleNotFound', id=sgr_id,
                                        resource='security_group_rule')
@@ -152,11 +155,12 @@ def security_group_rules_read(self, sg_obj, fields=None, filters=None):
             if filter_ids and sg_rule.get_rule_uuid() not in filter_ids:
                 continue
 
-            sg_info = self._security_group_rule_vnc_to_neutron(sg_obj.uuid,
-                                                               sg_rule,
-                                                               sg_obj,
-                                                               fields=fields)
-            sg_rules.append(sg_info)
+            sgr_info = self._security_group_rule_vnc_to_neutron(sg_obj.uuid,
+                                                                sg_rule,
+                                                                sg_obj,
+                                                                fields=fields)
+            if sgr_info:
+                sg_rules.append(sgr_info)
 
         return sg_rules
     # end security_group_rules_read