Support for etcd migration

cluster/gce/config-test.sh

@@ -36,7 +36,7 @@ KUBE_APISERVER_REQUEST_TIMEOUT=300
 PREEMPTIBLE_NODE=${PREEMPTIBLE_NODE:-false}
 PREEMPTIBLE_MASTER=${PREEMPTIBLE_MASTER:-false}
 
-MASTER_OS_DISTRIBUTION=${KUBE_MASTER_OS_DISTRIBUTION:-${KUBE_OS_DISTRIBUTION:-gci}}
+MASTER_OS_DISTRIBUTION=${KUBE_MASTER_OS_DISTRIBUTION:-${KUBE_OS_DISTRIBUTION:-debian}}
 NODE_OS_DISTRIBUTION=${KUBE_NODE_OS_DISTRIBUTION:-${KUBE_OS_DISTRIBUTION:-debian}}
 # By default a cluster will be started with the master on GCI and nodes on
 # containervm. If you are updating the containervm version, update this
@@ -161,7 +161,7 @@ KUBE_UP_AUTOMATIC_CLEANUP=${KUBE_UP_AUTOMATIC_CLEANUP:-false}
 TEST_CLUSTER="${TEST_CLUSTER:-true}"
 
 # Storage backend. 'etcd2' supported, 'etcd3' experimental.
-STORAGE_BACKEND=${STORAGE_BACKEND:-etcd2}
+STORAGE_BACKEND=${STORAGE_BACKEND:-etcd3}
 
 # OpenContrail networking plugin specific settings
 NETWORK_PROVIDER="${NETWORK_PROVIDER:-kubenet}" # none, opencontrail, flannel, kubenet

cluster/gce/gci/configure-helper.sh

@@ -543,6 +543,7 @@ function prepare-etcd-manifest {
   sed -i -e "s@{{ *cpulimit *}}@\"$4\"@g" "${temp_file}"
   sed -i -e "s@{{ *hostname *}}@$host_name@g" "${temp_file}"
   sed -i -e "s@{{ *etcd_cluster *}}@$etcd_cluster@g" "${temp_file}"
+  sed -i -e "s@{{ *storage_backend *}}@${STORAGE_BACKEND:-etcd2}@g" "${temp_file}"
   sed -i -e "s@{{ *cluster_state *}}@$cluster_state@g" "${temp_file}"
   # Replace the volume host path.
   sed -i -e "s@/mnt/master-pd/var/etcd@/mnt/disks/master-pd/var/etcd@g" "${temp_file}"

cluster/gce/trusty/configure-helper.sh

@@ -429,6 +429,7 @@ prepare_etcd_manifest() {
   sed -i -e "s@{{ *cpulimit *}}@\"$4\"@g" "${etcd_temp_file}"
   sed -i -e "s@{{ *hostname *}}@$host_name@g" "${etcd_temp_file}"
   sed -i -e "s@{{ *etcd_cluster *}}@$etcd_cluster@g" "${etcd_temp_file}"
+  sed -i -e "s@{{ *storage_backend *}}@${STORAGE_BACKEND:-etcd2}@g" "${temp_file}"
   sed -i -e "s@{{ *cluster_state *}}@$cluster_state@g" "${etcd_temp_file}"
   # Replace the volume host path
   sed -i -e "s@/mnt/master-pd/var/etcd@/mnt/disks/master-pd/var/etcd@g" "${etcd_temp_file}"

cluster/images/etcd/Dockerfile

@@ -16,4 +16,4 @@ FROM BASEIMAGE
 MAINTAINER Dawn Chen <dawnchen@google.com>
 
 EXPOSE 2379 2380 4001 7001
-COPY etcd etcdctl /usr/local/bin/
+COPY etcd etcdctl migrate-if-needed.sh /usr/local/bin/

cluster/images/etcd/Makefile

@@ -19,7 +19,7 @@
 
 TAG?=3.0.4
 ARCH?=amd64
-REGISTRY?=gcr.io/google_containers
+REGISTRY?=gcr.io/groovy-sentry-504
 GOLANG_VERSION?=1.6.3
 GOARM=6
 TEMP_DIR:=$(shell mktemp -d)

cluster/images/etcd/migrate-if-needed.sh

@@ -0,0 +1,64 @@
+#!/bin/sh
+
+# Copyright 2016 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This script performs data migration between etcd2 and etcd3 versions
+# if needed.
+# Expected usage of it is:
+#   ./migrate_if_needed <target-storage> <data-dir>
+# It will look into the contents of file <data-dir>/version.txt to
+# determine the current storage version (no file means etcd2).
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+if [ "$#" -ne 2 ]; then
+  echo "Incorrect number of argument"
+  echo "Expected usage: ./migrate_if_needed <target-storage> <data-dir>"
+  exit 1
+fi
+
+TARGET_STORAGE=$1
+DATA_DIRECTORY=$2
+VERSION_FILE="version.txt"
+
+CURRENT_STORAGE='etcd2'
+if [ -e "${DATA_DIRECTORY}/${VERSION_FILE}" ]; then
+  CURRENT_STORAGE="$(cat ${DATA_DIRECTORY}/${VERSION_FILE})"
+fi
+
+if [ "${CURRENT_STORAGE}" = "etcd2" -a "${TARGET_STORAGE}" = "etcd3" ]; then
+  # If directory doesn't exist or is empty, this means that there aren't any
+  # data for migration, which means we can skip this step.
+  if [ -d "${DATA_DIRECTORY}" ]; then
+    if [ "$(ls -A ${DATA_DIRECTORY})" ]; then
+      echo "Performing etcd2 -> etcd3 migration"
+      # TODO: Pass a correct transformer to handle TTLs.
+      ETCDCTL_API=3 /usr/local/bin/etcdctl migrate --data-dir=${DATA_DIRECTORY}
+    fi
+  fi
+fi
+
+if [ "${CURRENT_STORAGE}" = "etcd3" -a "${TARGET_STORAGE}" = "etcd2" ]; then
+  echo "Performing etcd3 -> etcd2 migration"
+  # TODO: Implement rollback once this will be supported.
+  echo "etcd3 -> etcd2 downgrade is NOT supported."
+fi
+
+# Write current storage version to avoid future migrations.
+# If directory doesn't exist, we need to create it first.
+mkdir -p "${DATA_DIRECTORY}"
+echo "${TARGET_STORAGE}" > "${DATA_DIRECTORY}/${VERSION_FILE}"

cluster/saltbase/salt/etcd/etcd.manifest

@@ -14,6 +14,7 @@
 {% endfor -%}
 {% set etcd_cluster = vars.etcd_cluster -%}
 {% set cluster_state = vars.cluster_state -%}
+{% set storage_backend = pillar.get('storage_backend_', 'etcd2') -%}
 
 {
 "apiVersion": "v1",
@@ -27,7 +28,7 @@
 "containers":[
     {
     "name": "etcd-container",
-    "image": "gcr.io/google_containers/etcd:3.0.3",
+    "image": "gcr.io/groovy-sentry-504/etcd:3.0.4",
     "resources": {
       "requests": {
         "cpu": {{ cpulimit }}
@@ -36,7 +37,7 @@
     "command": [
               "/bin/sh",
               "-c",
-              "/usr/local/bin/etcd --name etcd-{{ hostname }} --listen-peer-urls http://{{ hostname }}:{{ server_port }} --initial-advertise-peer-urls http://{{ hostname }}:{{ server_port }} --advertise-client-urls http://127.0.0.1:{{ port }} --listen-client-urls http://127.0.0.1:{{ port }} --data-dir /var/etcd/data{{ suffix }} --initial-cluster-state {{ cluster_state }} --initial-cluster {{ etcd_cluster }} 1>>/var/log/etcd{{ suffix }}.log 2>&1"
+              "/usr/local/bin/migrate-if-needed.sh {{ storage_backend }} /var/etcd/data{{ suffix }}; /usr/local/bin/etcd --name etcd-{{ hostname }} --listen-peer-urls http://{{ hostname }}:{{ server_port }} --initial-advertise-peer-urls http://{{ hostname }}:{{ server_port }} --advertise-client-urls http://127.0.0.1:{{ port }} --listen-client-urls http://127.0.0.1:{{ port }} --data-dir /var/etcd/data{{ suffix }} --initial-cluster-state {{ cluster_state }} --initial-cluster {{ etcd_cluster }} 1>>/var/log/etcd{{ suffix }}.log 2>&1"
             ],
     "livenessProbe": {
       "httpGet": {