Catch exceptions for deleted pod.

It might happen, that during adding and instantly removing pod, vif
handler will not be able to set the finalizer for such object, resulting
in error. In this patch we prevent for such case.

Closes-Bug: 1894212
Change-Id: I5b3b4b36ae0c2fca7c16153f75c62607efbc3ce4

kuryr_kubernetes/controller/handlers/kuryrport.py

@@ -133,8 +133,13 @@ class KuryrPortHandler(k8s_base.ResourceEventHandler):
             LOG.error("Pod %s/%s doesn't exists, deleting orphaned KuryrPort",
                       namespace, name)
             # TODO(gryf): Free resources
-            self.k8s.remove_finalizer(kuryrport_crd,
-                                      constants.KURYRPORT_FINALIZER)
+            try:
+                self.k8s.remove_finalizer(kuryrport_crd,
+                                          constants.KURYRPORT_FINALIZER)
+            except k_exc.K8sClientException as ex:
+                LOG.exception("Failed to remove finalizer from KuryrPort %s",
+                              ex)
+                raise
             return
 
         if 'deletionTimestamp' not in pod['metadata']:

kuryr_kubernetes/controller/handlers/lbaas.py

@@ -56,7 +56,8 @@ class ServiceHandler(k8s_base.ResourceEventHandler):
         k8s = clients.get_kubernetes_client()
         loadbalancer_crd = k8s.get_loadbalancer_crd(service)
         try:
-            self._patch_service_finalizer(service)
+            if not self._patch_service_finalizer(service):
+                return
         except k_exc.K8sClientException as ex:
             LOG.exception("Failed to set service finalizer: %s", ex)
             raise
@@ -100,7 +101,7 @@ class ServiceHandler(k8s_base.ResourceEventHandler):
 
     def _patch_service_finalizer(self, service):
         k8s = clients.get_kubernetes_client()
-        k8s.add_finalizer(service, k_const.SERVICE_FINALIZER)
+        return k8s.add_finalizer(service, k_const.SERVICE_FINALIZER)
 
     def on_finalize(self, service):
         k8s = clients.get_kubernetes_client()

kuryr_kubernetes/controller/handlers/vif.py

@@ -75,7 +75,15 @@ class VIFHandler(k8s_base.ResourceEventHandler):
         # subsequent updates of the pod, add_finalizer will ignore this if
         # finalizer exists.
         k8s = clients.get_kubernetes_client()
-        k8s.add_finalizer(pod, constants.POD_FINALIZER)
+
+        try:
+            if not k8s.add_finalizer(pod, constants.POD_FINALIZER):
+                # NOTE(gryf) It might happen that pod will be deleted even
+                # before we got here.
+                return
+        except k_exc.K8sClientException as ex:
+            LOG.exception("Failed to add finalizer to pod object: %s", ex)
+            raise
 
         if self._move_annotations_to_crd(pod):
             return
@@ -114,7 +122,11 @@ class VIFHandler(k8s_base.ResourceEventHandler):
             kp = k8s.get(KURYRPORT_URI.format(ns=pod["metadata"]["namespace"],
                                               crd=pod["metadata"]["name"]))
         except k_exc.K8sResourceNotFound:
-            k8s.remove_finalizer(pod, constants.POD_FINALIZER)
+            try:
+                k8s.remove_finalizer(pod, constants.POD_FINALIZER)
+            except k_exc.K8sClientException as ex:
+                LOG.exception('Failed to remove finalizer from pod: %s', ex)
+                raise
             return
 
         if 'deletionTimestamp' in kp['metadata']:

kuryr_kubernetes/k8s_client.py

@@ -227,7 +227,7 @@ class K8sClient(object):
     #              duplication, but I don't see a nice way to avoid it.
     def add_finalizer(self, obj, finalizer):
         if finalizer in obj['metadata'].get('finalizers', []):
-            return obj
+            return True
 
         path = obj['metadata']['selfLink']
         LOG.debug(f"Add finalizer {finalizer} to {path}")
@@ -250,15 +250,18 @@ class K8sClient(object):
                                           verify=self.verify_server)
 
             if response.ok:
-                return response.json()
+                return True
 
             try:
                 self._raise_from_response(response)
+            except (exc.K8sForbidden, exc.K8sResourceNotFound):
+                # Object is being deleting or gone. Return.
+                return False
             except exc.K8sConflict:
                 obj = self.get(path)
                 if finalizer in obj['metadata'].get('finalizers', []):
                     # Finalizer is there, return.
-                    return obj
+                    return True
 
         # If after 3 iterations there's still conflict, just raise.
         self._raise_from_response(response)
@@ -275,7 +278,7 @@ class K8sClient(object):
                 finalizers.remove(finalizer)
             except ValueError:
                 # Finalizer is not there, return.
-                return obj
+                return True
 
             data = {
                 'metadata': {
@@ -289,7 +292,7 @@ class K8sClient(object):
                                           verify=self.verify_server)
 
             if response.ok:
-                return response.json()
+                return True
 
             try:
                 try:
@@ -298,7 +301,7 @@ class K8sClient(object):
                     obj = self.get(path)
             except exc.K8sResourceNotFound:
                 # Object is gone already, stop.
-                return None
+                return False
 
         # If after 3 iterations there's still conflict, just raise.
         self._raise_from_response(response)

kuryr_kubernetes/tests/unit/controller/handlers/test_vif.py

@@ -308,6 +308,23 @@ class TestVIFHandler(test_base.TestCase):
         self._request_additional_vifs.assert_not_called()
         self._activate_vif.assert_not_called()
 
+    @mock.patch('kuryr_kubernetes.clients.get_kubernetes_client')
+    @mock.patch('kuryr_kubernetes.controller.drivers.utils.is_host_network')
+    def test_on_present_pod_finalizer_exception(self, m_host_network,
+                                                m_get_k8s_client):
+        m_host_network.return_value = False
+        self._matc.return_value = True
+        k8s = mock.MagicMock()
+        k8s.add_finalizer.side_effect = k_exc.K8sClientException
+        m_get_k8s_client.return_value = k8s
+
+        self.assertRaises(k_exc.K8sClientException,
+                          h_vif.VIFHandler.on_present, self._handler,
+                          self._pod)
+
+        k8s.add_finalizer.assert_called_once_with(self._pod,
+                                                  k_const.POD_FINALIZER)
+
     @mock.patch('kuryr_kubernetes.clients.get_kubernetes_client')
     @mock.patch('kuryr_kubernetes.controller.drivers.utils.get_kuryrport')
     def test_on_finalize_crd(self, m_get_kuryrport, m_get_k8s_client):