Merge pull request kubernetes#77930 from mm4tt/upload_kubeconfig

Upload kubeconfig to master metadata in tests.

Author: k8s-ci-robot

cluster/gce/config-test.sh

@@ -525,3 +525,5 @@ WINDOWS_NODE_TAINTS="${WINDOWS_NODE_TAINTS:-node.kubernetes.io/os=win1809:NoSche
 GCE_PRIVATE_CLUSTER="${KUBE_GCE_PRIVATE_CLUSTER:-false}"
 
 ETCD_LISTEN_CLIENT_IP=0.0.0.0
+
+GCE_UPLOAD_KUBCONFIG_TO_MASTER_METADATA=true

cluster/gce/util.sh

@@ -3017,6 +3017,11 @@ function check-cluster() {
 
   # ensures KUBECONFIG is set
   get-kubeconfig-basicauth
+
+  if [[ ${GCE_UPLOAD_KUBCONFIG_TO_MASTER_METADATA:-} == "true" ]]; then
+    gcloud compute instances add-metadata "${MASTER_NAME}" --zone="${ZONE}"  --metadata-from-file="kubeconfig=${KUBECONFIG}" || true
+  fi
+
   echo
   echo -e "${color_green}Kubernetes cluster is running.  The master is running at:"
   echo