Support testing on minikube. (#485)

* Support testing on minikube.

* When using minikube we don't want call configure_kubectl which calls
  gcloud container clusters get-credentials.

* Instead we just need to call load_kube_config to load the kube config file.

* Related to kubeflow/testing#6

* Add a TODO.

* Fix lint issue.

py/test_runner.py

@@ -114,7 +114,16 @@ def run_test(args):  # pylint: disable=too-many-branches,too-many-statements
   project = args.project
   cluster_name = args.cluster
   zone = args.zone
-  util.configure_kubectl(project, zone, cluster_name)
+  # TODO(jlewi): When using GKE we should copy the .kube config and any other
+  # files to the test directory. We should then set the environment variable
+  # KUBECONFIG to point at that file. This should prevent us from having
+  # to rerun util.configure_kubectl on each step. Instead we could run it once
+  # as part of GKE cluster creation and store the config in the NFS directory.
+  # This would make the handling of credentials
+  # and KUBECONFIG more consistent between GKE and minikube and eventually
+  # this could be extended to other K8s deployments.
+  if cluster_name:
+    util.configure_kubectl(project, zone, cluster_name)
   util.load_kube_config()
 
   api_client = k8s_client.ApiClient()

py/util.py

@@ -1,6 +1,7 @@
 """Utilities used by our python scripts for building and releasing."""
 from __future__ import print_function
 
+# TODO(jlewi): We should remove this file and use util in kubeflow/testing repository.
 import datetime
 import logging
 import os