Enable using gcr.io as a Docker registry mirror.

This only affects clusters running under GCE.

cluster/common.sh

@@ -482,6 +482,7 @@ SERVICE_CLUSTER_IP_RANGE: $(yaml-quote ${SERVICE_CLUSTER_IP_RANGE})
 KUBERNETES_MASTER_NAME: $(yaml-quote ${MASTER_NAME})
 ALLOCATE_NODE_CIDRS: $(yaml-quote ${ALLOCATE_NODE_CIDRS:-false})
 ENABLE_CLUSTER_MONITORING: $(yaml-quote ${ENABLE_CLUSTER_MONITORING:-none})
+DOCKER_REGISTRY_MIRROR_URL: $(yaml-quote ${DOCKER_REGISTRY_MIRROR_URL:-})
 ENABLE_L7_LOADBALANCING: $(yaml-quote ${ENABLE_L7_LOADBALANCING:-none})
 ENABLE_CLUSTER_LOGGING: $(yaml-quote ${ENABLE_CLUSTER_LOGGING:-false})
 ENABLE_CLUSTER_UI: $(yaml-quote ${ENABLE_CLUSTER_UI:-false})

cluster/gce/config-default.sh

@@ -61,6 +61,9 @@ POLL_SLEEP_INTERVAL="${POLL_SLEEP_INTERVAL:-3}"
 SERVICE_CLUSTER_IP_RANGE="${SERVICE_CLUSTER_IP_RANGE:-10.0.0.0/16}"  # formerly PORTAL_NET
 ALLOCATE_NODE_CIDRS=true
 
+# When set to true, Docker Cache is enabled by default as part of the cluster bring up.
+ENABLE_DOCKER_REGISTRY_CACHE=true
+
 # Optional: Deploy a L7 loadbalancer controller to fulfill Ingress requests:
 #   glbc           - CE L7 Load Balancer Controller
 ENABLE_L7_LOADBALANCING="${KUBE_ENABLE_L7_LOADBALANCING:-glbc}"

cluster/gce/config-test.sh

@@ -62,6 +62,9 @@ EXTRA_DOCKER_OPTS="${EXTRA_DOCKER_OPTS:-}"
 POLL_SLEEP_INTERVAL=3
 SERVICE_CLUSTER_IP_RANGE="10.0.0.0/16"  # formerly PORTAL_NET
 
+# When set to true, Docker Cache is enabled by default as part of the cluster bring up.
+ENABLE_DOCKER_REGISTRY_CACHE=true
+
 # Optional: Deploy a L7 loadbalancer controller to fulfill Ingress requests:
 #   glbc           - CE L7 Load Balancer Controller
 ENABLE_L7_LOADBALANCING="${KUBE_ENABLE_L7_LOADBALANCING:-glbc}"

cluster/gce/configure-vm.sh

@@ -898,6 +898,13 @@ function node-docker-opts() {
   if [[ -n "${EXTRA_DOCKER_OPTS-}" ]]; then
     DOCKER_OPTS="${DOCKER_OPTS:-} ${EXTRA_DOCKER_OPTS}"
   fi
+
+  # Decide whether to enable a docker registry mirror. This is taken from
+  # the "kube-env" metadata value.
+  if [[ -n "${DOCKER_REGISTRY_MIRROR_URL:-}" ]]; then
+    echo "Enable docker registry mirror at: ${DOCKER_REGISTRY_MIRROR_URL}"
+    DOCKER_OPTS="${DOCKER_OPTS:-} --registry-mirror=${DOCKER_REGISTRY_MIRROR_URL}"
+  fi
 }
 
 function salt-grains() {

cluster/gce/util.sh

@@ -193,6 +193,10 @@ function set-preferred-region() {
   else
     KUBE_ADDON_REGISTRY="gcr.io/google_containers"
   fi
+
+  if [[ "${ENABLE_DOCKER_REGISTRY_CACHE:-}" == "true" ]]; then
+    DOCKER_REGISTRY_MIRROR_URL="https://${preferred}-mirror.gcr.io"
+  fi
 }
 
 # Take the local tar files and upload them to Google Storage.  They will then be