Switch COS image to m81.

Author: cheftako

cluster/gce/config-default.sh

@@ -83,7 +83,7 @@ fi
 # you are updating the os image versions, update this variable.
 # Also please update corresponding image for node e2e at:
 # https://github.com/kubernetes/kubernetes/blob/master/test/e2e_node/jenkins/image-config.yaml
-GCI_VERSION=${KUBE_GCI_VERSION:-cos-77-12371-175-0}
+GCI_VERSION=${KUBE_GCI_VERSION:-cos-81-12871-59-0}
 MASTER_IMAGE=${KUBE_GCE_MASTER_IMAGE:-}
 MASTER_IMAGE_PROJECT=${KUBE_GCE_MASTER_PROJECT:-cos-cloud}
 NODE_IMAGE=${KUBE_GCE_NODE_IMAGE:-${GCI_VERSION}}

cluster/gce/config-test.sh

@@ -90,7 +90,7 @@ ALLOWED_NOTREADY_NODES="${ALLOWED_NOTREADY_NODES:-$(($(get-num-nodes) / 100))}"
 # you are updating the os image versions, update this variable.
 # Also please update corresponding image for node e2e at:
 # https://github.com/kubernetes/kubernetes/blob/master/test/e2e_node/jenkins/image-config.yaml
-GCI_VERSION=${KUBE_GCI_VERSION:-cos-77-12371-175-0}
+GCI_VERSION=${KUBE_GCI_VERSION:-cos-81-12871-59-0}
 MASTER_IMAGE=${KUBE_GCE_MASTER_IMAGE:-}
 MASTER_IMAGE_PROJECT=${KUBE_GCE_MASTER_PROJECT:-cos-cloud}
 NODE_IMAGE=${KUBE_GCE_NODE_IMAGE:-${GCI_VERSION}}