Work out situation with KUBERNETES_NODE_NAME

This reverts commit f0cde86ee6 as it turns
out that variable is actually used by kuryr-daemon and fixes the way
kuryr-controller detects its identity to match how leader-elector is
doing it.

Change-Id: I95c2d3e1760a938d40d57a99fb87b6f02ca7f64a
Closes-Bug: 1798835

devstack/lib/kuryr_kubernetes

@@ -569,11 +569,6 @@ EOF
         imagePullPolicy: Never
         name: controller
         terminationMessagePath: "/dev/termination-log"
-        env:
-        - name: KUBERNETES_NODE_NAME
-          valueFrom:
-            fieldRef:
-              fieldPath: spec.nodeName
         volumeMounts:
         - name: config-volume
           mountPath: "/etc/kuryr/kuryr.conf"
@@ -642,6 +637,10 @@ spec:
         imagePullPolicy: Never
         command: [ "cni_ds_init" ]
         env:
+        - name: KUBERNETES_NODE_NAME
+          valueFrom:
+            fieldRef:
+              fieldPath: spec.nodeName
         - name: KURYR_CNI_POD_NAME
           valueFrom:
             fieldRef:

kuryr_kubernetes/tests/unit/test_utils.py

@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import mock
-import os
 
 from os_vif import objects
 from oslo_config import cfg
@@ -27,25 +26,12 @@ CONF = cfg.CONF
 
 class TestUtils(test_base.TestCase):
     @mock.patch('socket.gethostname')
-    def test_get_node_name_socket(self, m_gethostname):
-        try:
-            del os.environ['KUBERNETES_NODE_NAME']
-        except KeyError:
-            pass
-
+    def test_get_node_name(self, m_gethostname):
         m_gethostname.return_value = 'foo'
         res = utils.get_node_name()
         self.assertEqual('foo', res)
         m_gethostname.assert_called_once_with()
 
-    @mock.patch('socket.gethostname')
-    def test_get_node_name_envvar(self, m_gethostname):
-        os.environ['KUBERNETES_NODE_NAME'] = 'bar'
-        m_gethostname.return_value = 'foo'
-        res = utils.get_node_name()
-        self.assertEqual('bar', res)
-        m_gethostname.assert_not_called()
-
     @mock.patch('requests.get')
     def test_get_leader_name(self, m_get):
         m_get.return_value = mock.Mock(json=mock.Mock(

kuryr_kubernetes/utils.py

@@ -10,7 +10,6 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import os
 import random
 import socket
 import time
@@ -129,10 +128,10 @@ def exponential_sleep(deadline, attempt, interval=DEFAULT_INTERVAL):
 
 
 def get_node_name():
-    try:
-        return os.environ['KUBERNETES_NODE_NAME']
-    except KeyError:
-        return socket.gethostname()
+    # leader-elector container based on K8s way of doing leader election is
+    # assuming that hostname it sees is the node id. Containers within a pod
+    # are sharing the hostname, so this will match what leader-elector returns.
+    return socket.gethostname()
 
 
 def get_leader_name():