Remove dead networks in current cluster.

There was already introduced port cleanup function, so in this patch
there is new function introduced for cleaning up unused networks and
subnets for whole deployment, by using identifier from description.

Change-Id: Ia11e8953fab3f9cd8f6598f9da94daae324b1bf8

kuryr_kubernetes/controller/service.py

@@ -173,8 +173,9 @@ class KuryrK8sService(service.Service, periodic_task.PeriodicTasks,
             handler.reconcile()
 
     @periodic_task.periodic_task(spacing=90, run_immediately=False)
-    def cleanup_dead_ports(self, context):
+    def cleanup_dead_resources(self, context):
         utils.cleanup_dead_ports()
+        utils.cleanup_dead_networks()
 
 
 def start():

kuryr_kubernetes/utils.py

@@ -770,3 +770,56 @@ def cleanup_dead_ports():
                 except os_exc.SDKException as ex:
                     LOG.warning('There was an issue with port "%s" '
                                 'removal: %s', port, ex)
+
+
+def cleanup_dead_networks():
+    """Cleanup all the dead networks and subnets without ports"""
+
+    tags = set(CONF.neutron_defaults.resource_tags)
+    if not tags:
+        return
+
+    os_net = clients.get_network_client()
+    k8s = clients.get_kubernetes_client()
+
+    desc = ",".join(CONF.neutron_defaults.resource_tags)
+
+    try:
+        crds = k8s.get(constants.K8S_API_CRD_KURYRNETWORKS)
+    except exceptions.K8sClientException as ex:
+        LOG.exception('Error fetching KuryrNetworks: %s', ex)
+        return
+
+    kuryr_net_ids = [i['status']['netId'] for i in crds['items']
+                     if i.get('status', {}).get('netId')]
+
+    for net in os_net.networks(description=desc):
+
+        if net.id in kuryr_net_ids:
+            # Find out, if there are more subnets than expected, which suppose
+            # to not have tags.
+            for subnet in os_net.subnets(network_id=net.id,
+                                         not_tags=list(tags)):
+                now = timeutils.utcnow(True)
+                subnet_time = timeutils.parse_isotime(subnet.updated_at)
+                if (now - subnet_time).seconds > ZOMBIE_AGE:
+                    try:
+                        os_net.delete_subnet(subnet)
+                    except os_exc.SDKException as ex:
+                        LOG.warning('There was an issue with removing subnet '
+                                    '"%s": %s', subnet, ex)
+                        continue
+
+        if len(os_net.ports(network_id=net.id)) > 0:
+            continue
+
+        now = timeutils.utcnow(True)
+        net_time = timeutils.parse_isotime(net.updated_at)
+        # NOTE(gryf): if network hanging more than 10 minutes consider it as a
+        # orphaned.
+        if (now - net_time).seconds > ZOMBIE_AGE:
+            try:
+                os_net.delete_network(net)
+            except os_exc.SDKException as ex:
+                LOG.warning('There was an issue with network "%s" '
+                            'removal: %s', net, ex)