Implemented creation of HA master for GCE on debian.

cluster/gce/debian/master-helper.sh

@@ -40,8 +40,32 @@ function create-master-instance {
 
   write-master-env
   prepare-startup-script
-  gcloud compute instances create "${MASTER_NAME}" \
-    ${address_opt} \
+  create-master-instance-internal "${MASTER_NAME}" "${address_opt}" "${preemptible_master}"
+}
+
+function replicate-master-instance() {
+  local existing_master_zone="${1}"
+  local existing_master_name="${2}"
+  local existing_master_replicas="${3}"
+
+  local kube_env="$(get-metadata "${existing_master_zone}" "${existing_master_name}" kube-env)"
+  # Substitute INITIAL_ETCD_CLUSTER to enable etcd clustering.
+  kube_env="$(echo "${kube_env}" | grep -v "INITIAL_ETCD_CLUSTER")"
+  kube_env="$(echo -e "${kube_env}\nINITIAL_ETCD_CLUSTER: '${existing_master_replicas},${REPLICA_NAME}'")"
+  echo "${kube_env}" > ${KUBE_TEMP}/master-kube-env.yaml
+  get-metadata "${existing_master_zone}" "${existing_master_name}" cluster-name > ${KUBE_TEMP}/cluster-name.txt
+  get-metadata "${existing_master_zone}" "${existing_master_name}" startup-script > ${KUBE_TEMP}/configure-vm.sh
+
+  create-master-instance-internal "${REPLICA_NAME}"
+}
+
+function create-master-instance-internal() {
+  local -r master_name="${1}"
+  local -r address_option="${2:-}"
+  local -r preemptible_master="${3:-}"
+
+  gcloud compute instances create "${master_name}" \
+    ${address_option} \
     --project "${PROJECT}" \
     --zone "${ZONE}" \
     --machine-type "${MASTER_SIZE}" \
@@ -53,7 +77,18 @@ function create-master-instance {
     --can-ip-forward \
     --metadata-from-file \
       "startup-script=${KUBE_TEMP}/configure-vm.sh,kube-env=${KUBE_TEMP}/master-kube-env.yaml,cluster-name=${KUBE_TEMP}/cluster-name.txt" \
-    --disk "name=${MASTER_NAME}-pd,device-name=master-pd,mode=rw,boot=no,auto-delete=no" \
+    --disk "name=${master_name}-pd,device-name=master-pd,mode=rw,boot=no,auto-delete=no" \
     --boot-disk-size "${MASTER_ROOT_DISK_SIZE:-10}" \
     ${preemptible_master}
 }
+
+# TODO: This is most likely not the best way to read metadata from the existing master.
+function get-metadata() {
+  local zone="${1}"
+  local name="${2}"
+  local key="${3}"
+  gcloud compute ssh "${name}" \
+    --project "${PROJECT}" \
+    --zone="${zone}" \
+    --command "curl \"http://metadata.google.internal/computeMetadata/v1/instance/attributes/${key}\" -H \"Metadata-Flavor: Google\"" 2>/dev/null
+}

cluster/gce/util.sh

@@ -595,9 +595,8 @@ function kube-up() {
     parse-master-env
     create-nodes
   elif [[ ${KUBE_EXPERIMENTAL_REPLICATE_EXISTING_MASTER:-} == "true" ]]; then
-    # TODO(jsz): implement adding replica for other distributions.
-    if  [[ "${MASTER_OS_DISTRIBUTION}" != "gci" ]]; then
-      echo "Master replication supported only for gci"
+    if  [[ "${MASTER_OS_DISTRIBUTION}" != "gci" && "${MASTER_OS_DISTRIBUTION}" != "debian" ]]; then
+      echo "Master replication supported only for gci and debian"
       return 1
     fi
     create-loadbalancer