GCI: Add two GCI specific metadata pairs

cluster/gce/trusty/helper.sh

@@ -18,17 +18,45 @@
 
 # The configuration is based on upstart, which is in Ubuntu up to 14.04 LTS (Trusty).
 # Ubuntu 15.04 and above replaced upstart with systemd as the init system.
-# Consequently, the configuration cannot work on these images.
+# Consequently, the configuration cannot work on these images. In release-1.2 branch,
+# GCI and Trusty share the configuration code. We have to keep the GCI specific code
+# here as long as the release-1.2 branch has not been deprecated.
 
+# Creates the GCI specific metadata files if they do not exit.
+# Assumed var
+#   KUBE_TEMP
+function ensure-gci-metadata-files {
+  if [[ ! -f "${KUBE_TEMP}/gci-update.txt" ]]; then
+    cat >"${KUBE_TEMP}/gci-update.txt" << EOF
+update_disabled
+EOF
+  fi
+  if [[ ! -f "${KUBE_TEMP}/gci-docker.txt" ]]; then
+    cat >"${KUBE_TEMP}/gci-docker.txt" << EOF
+true
+EOF
+  fi
+}
 
 # $1: template name (required)
 function create-node-instance-template {
   local template_name="$1"
-  create-node-template "$template_name" "${scope_flags[*]}" \
-    "kube-env=${KUBE_TEMP}/node-kube-env.yaml" \
-    "user-data=${KUBE_ROOT}/cluster/gce/trusty/node.yaml" \
-    "configure-sh=${KUBE_ROOT}/cluster/gce/trusty/configure.sh" \
-    "cluster-name=${KUBE_TEMP}/cluster-name.txt"
+  if [[ "${OS_DISTRIBUTION}" == "gci" && "${NODE_IMAGE}" == gci* ]]; then
+    ensure-gci-metadata-files
+    create-node-template "$template_name" "${scope_flags[*]}" \
+      "kube-env=${KUBE_TEMP}/node-kube-env.yaml" \
+      "user-data=${KUBE_ROOT}/cluster/gce/trusty/node.yaml" \
+      "configure-sh=${KUBE_ROOT}/cluster/gce/trusty/configure.sh" \
+      "cluster-name=${KUBE_TEMP}/cluster-name.txt" \
+      "gci-update-strategy=${KUBE_TEMP}/gci-update.txt" \
+      "gci-ensure-gke-docker=${KUBE_TEMP}/gci-docker.txt"
+  else
+    create-node-template "$template_name" "${scope_flags[*]}" \
+      "kube-env=${KUBE_TEMP}/node-kube-env.yaml" \
+      "user-data=${KUBE_ROOT}/cluster/gce/trusty/node.yaml" \
+      "configure-sh=${KUBE_ROOT}/cluster/gce/trusty/configure.sh" \
+      "cluster-name=${KUBE_TEMP}/cluster-name.txt"
+  fi
 }
 
 # create-master-instance creates the master instance. If called with
@@ -47,6 +75,11 @@ function create-node-instance-template {
 function create-master-instance {
   local address_opt=""
   [[ -n ${1:-} ]] && address_opt="--address ${1}"
+  local image_metadata=""
+  if [[ "${OS_DISTRIBUTION}" == "gci" && "${MASTER_IMAGE}" == gci* ]]; then
+    ensure-gci-metadata-files
+    image_metadata=",gci-update-strategy=${KUBE_TEMP}/gci-update.txt,gci-ensure-gke-docker=${KUBE_TEMP}/gci-docker.txt"
+  fi
 
   write-master-env
   gcloud compute instances create "${MASTER_NAME}" \
@@ -61,6 +94,6 @@ function create-master-instance {
     --scopes "storage-ro,compute-rw,monitoring,logging-write" \
     --can-ip-forward \
     --metadata-from-file \
-      "kube-env=${KUBE_TEMP}/master-kube-env.yaml,user-data=${KUBE_ROOT}/cluster/gce/trusty/master.yaml,configure-sh=${KUBE_ROOT}/cluster/gce/trusty/configure.sh,cluster-name=${KUBE_TEMP}/cluster-name.txt" \
+      "kube-env=${KUBE_TEMP}/master-kube-env.yaml,user-data=${KUBE_ROOT}/cluster/gce/trusty/master.yaml,configure-sh=${KUBE_ROOT}/cluster/gce/trusty/configure.sh,cluster-name=${KUBE_TEMP}/cluster-name.txt${image_metadata}" \
     --disk "name=${MASTER_NAME}-pd,device-name=master-pd,mode=rw,boot=no,auto-delete=no"
 }