Pass image_pull_policy in KubernetesPodOperator correctly (#13289)

* pass image_pull_policy to V1Container

image_pull_policy is not being passed into the V1Container in
KubernetesPodOperator. This commit fixes this.

* add test for image_pull_policy not set

image_pull_policy should be IfNotPresent by default if
it's not set. The test ensure the correct value is passed
to the V1Container object.

airflow/providers/cncf/kubernetes/operators/kubernetes_pod.py

@@ -431,6 +431,7 @@ class KubernetesPodOperator(BaseOperator):  # pylint: disable=too-many-instance-
                         name="base",
                         command=self.cmds,
                         ports=self.ports,
+                        image_pull_policy=self.image_pull_policy,
                         resources=self.k8s_resources,
                         volume_mounts=self.volume_mounts,
                         args=self.arguments,

tests/providers/cncf/kubernetes/operators/test_kubernetes_pod.py

@@ -99,6 +99,59 @@ class TestKubernetesPodOperator(unittest.TestCase):
             [k8s.V1LocalObjectReference(name=fake_pull_secrets)],
         )
 
+    @mock.patch("airflow.kubernetes.pod_launcher.PodLauncher.start_pod")
+    @mock.patch("airflow.kubernetes.pod_launcher.PodLauncher.monitor_pod")
+    @mock.patch("airflow.kubernetes.kube_client.get_kube_client")
+    def test_image_pull_policy_not_set(self, mock_client, monitor_mock, start_mock):
+        from airflow.utils.state import State
+
+        k = KubernetesPodOperator(
+            namespace='default',
+            image="ubuntu:16.04",
+            cmds=["bash", "-cx"],
+            arguments=["echo 10"],
+            labels={"foo": "bar"},
+            name="test",
+            task_id="task",
+            in_cluster=False,
+            do_xcom_push=False,
+            cluster_context='default',
+        )
+        monitor_mock.return_value = (State.SUCCESS, None)
+        context = self.create_context(k)
+        k.execute(context=context)
+        self.assertEqual(
+            start_mock.call_args[0][0].spec.containers[0].image_pull_policy,
+            'IfNotPresent',
+        )
+
+    @mock.patch("airflow.kubernetes.pod_launcher.PodLauncher.start_pod")
+    @mock.patch("airflow.kubernetes.pod_launcher.PodLauncher.monitor_pod")
+    @mock.patch("airflow.kubernetes.kube_client.get_kube_client")
+    def test_image_pull_policy_correctly_set(self, mock_client, monitor_mock, start_mock):
+        from airflow.utils.state import State
+
+        k = KubernetesPodOperator(
+            namespace='default',
+            image="ubuntu:16.04",
+            cmds=["bash", "-cx"],
+            arguments=["echo 10"],
+            labels={"foo": "bar"},
+            name="test",
+            task_id="task",
+            in_cluster=False,
+            do_xcom_push=False,
+            image_pull_policy='Always',
+            cluster_context='default',
+        )
+        monitor_mock.return_value = (State.SUCCESS, None)
+        context = self.create_context(k)
+        k.execute(context=context)
+        self.assertEqual(
+            start_mock.call_args[0][0].spec.containers[0].image_pull_policy,
+            'Always',
+        )
+
     @mock.patch("airflow.kubernetes.pod_launcher.PodLauncher.start_pod")
     @mock.patch("airflow.kubernetes.pod_launcher.PodLauncher.monitor_pod")
     @mock.patch("airflow.kubernetes.pod_launcher.PodLauncher.delete_pod")