#!/usr/bin/env bash # 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 disaster recovery of etcd from the backup data. # Assumptions: # - backup was done using etcdctl command: # a) in case of etcd2 # $ etcdctl backup --data-dir= # produced .snap and .wal files # b) in case of etcd3 # $ etcdctl --endpoints=
snapshot save # produced .db file # - version.txt file is in the current directory (if it isn't it will be # defaulted to "2.2.1/etcd2"). Based on this file, the script will # decide to which version we are restoring (procedures are different # for etcd2 and etcd3). # - in case of etcd2 - *.snap and *.wal files are in current directory # - in case of etcd3 - *.db file is in the current directory # - the script is run as root # - for event etcd, we only support clearing it - to do it, you need to # set RESET_EVENT_ETCD=true env var. set -o errexit set -o nounset set -o pipefail # Version file contains information about current version in the format: # / (e.g. "3.0.12/etcd3"). # # If the file doesn't exist we assume "2.2.1/etcd2" configuration is # the current one and create a file with such configuration. # The restore procedure is chosen based on this information. VERSION_FILE="version.txt" # Make it possible to overwrite version file (or default version) # with VERSION_CONTENTS env var. if [ -n "${VERSION_CONTENTS:-}" ]; then echo "${VERSION_CONTENTS}" > "${VERSION_FILE}" fi if [ ! -f "${VERSION_FILE}" ]; then echo "2.2.1/etcd2" > "${VERSION_FILE}" fi VERSION_CONTENTS="$(cat ${VERSION_FILE})" ETCD_VERSION="$(echo $VERSION_CONTENTS | cut -d '/' -f 1)" ETCD_API="$(echo $VERSION_CONTENTS | cut -d '/' -f 2)" # Name is used only in case of etcd3 mode, to appropriate set the metadata # for the etcd data. # NOTE: NAME HAS TO BE EQUAL TO WHAT WE USE IN --name flag when starting etcd. NAME="${NAME:-etcd-$(hostname)}" INITIAL_CLUSTER="${INITIAL_CLUSTER:-${NAME}=http://localhost:2380}" INITIAL_ADVERTISE_PEER_URLS="${INITIAL_ADVERTISE_PEER_URLS:-http://localhost:2380}" # Port on which etcd is exposed. etcd_port=2379 event_etcd_port=4002 # Wait until both etcd instances are up wait_for_etcd_up() { port=$1 # TODO: As of 3.0.x etcd versions, all 2.* and 3.* versions return # {"health": "true"} on /health endpoint in healthy case. # However, we should come with a regex for it to avoid future break. health_ok="{\"health\": \"true\"}" for i in $(seq 120); do # TODO: Is it enough to look into /health endpoint? health=$(curl --silent http://127.0.0.1:${port}/health) if [ "${health}" == "${health_ok}" ]; then return 0 fi sleep 1 done return 1 } # Wait until apiserver is up. wait_for_cluster_healthy() { for i in $(seq 120); do cs_status=$(kubectl get componentstatuses -o template --template='{{range .items}}{{with index .conditions 0}}{{.type}}:{{.status}}{{end}}{{"\n"}}{{end}}') || true componentstatuses=$(echo "${cs_status}" | grep -c 'Healthy:') || true healthy=$(echo "${cs_status}" | grep -c 'Healthy:True') || true if [ "${componentstatuses}" -eq "${healthy}" ]; then return 0 fi sleep 1 done return 1 } # Wait until etcd and apiserver pods are down. wait_for_etcd_and_apiserver_down() { for i in $(seq 120); do etcd=$(docker ps | grep etcd-server | wc -l) apiserver=$(docker ps | grep apiserver | wc -l) # TODO: Theoretically it is possible, that apiserver and or etcd # are currently down, but Kubelet is now restarting them and they # will reappear again. We should avoid it. if [ "${etcd}" -eq "0" -a "${apiserver}" -eq "0" ]; then return 0 fi sleep 1 done return 1 } # Move the manifest files to stop etcd and kube-apiserver # while we swap the data out from under them. MANIFEST_DIR="/etc/kubernetes/manifests" MANIFEST_BACKUP_DIR="/etc/kubernetes/manifests-backups" mkdir -p "${MANIFEST_BACKUP_DIR}" echo "Moving etcd(s) & apiserver manifest files to ${MANIFEST_BACKUP_DIR}" # If those files were already moved (e.g. during previous # try of backup) don't fail on it. mv "${MANIFEST_DIR}/kube-apiserver.manifest" "${MANIFEST_BACKUP_DIR}" || true mv "${MANIFEST_DIR}/etcd.manifest" "${MANIFEST_BACKUP_DIR}" || true mv "${MANIFEST_DIR}/etcd-events.manifest" "${MANIFEST_BACKUP_DIR}" || true # Wait for the pods to be stopped echo "Waiting for etcd and kube-apiserver to be down" if ! wait_for_etcd_and_apiserver_down; then # Couldn't kill etcd and apiserver. echo "Downing etcd and apiserver failed" exit 1 fi read -rsp $'Press enter when all etcd instances are down...\n' # Create the sort of directory structure that etcd expects. # If this directory already exists, remove it. BACKUP_DIR="/var/tmp/backup" rm -rf "${BACKUP_DIR}" if [ "${ETCD_API}" == "etcd2" ]; then echo "Preparing etcd backup data for restore" # In v2 mode, we simply copy both snap and wal files to a newly created # directory. After that, we start etcd with --force-new-cluster option # that (according to the etcd documentation) is required to recover from # a backup. echo "Copying data to ${BACKUP_DIR} and restoring there" mkdir -p "${BACKUP_DIR}/member/snap" mkdir -p "${BACKUP_DIR}/member/wal" # If the cluster is relatively new, there can be no .snap file. mv *.snap "${BACKUP_DIR}/member/snap/" || true mv *.wal "${BACKUP_DIR}/member/wal/" # TODO(jsz): This won't work with HA setups (e.g. do we need to set --name flag)? echo "Starting etcd ${ETCD_VERSION} to restore data" image=$(docker run -d -v ${BACKUP_DIR}:/var/etcd/data \ --net=host -p ${etcd_port}:${etcd_port} \ "k8s.gcr.io/etcd:${ETCD_VERSION}" /bin/sh -c \ "/usr/local/bin/etcd --data-dir /var/etcd/data --force-new-cluster") if [ "$?" -ne "0" ]; then echo "Docker container didn't started correctly" exit 1 fi echo "Container ${image} created, waiting for etcd to report as healthy" if ! wait_for_etcd_up "${etcd_port}"; then echo "Etcd didn't come back correctly" exit 1 fi # Kill that etcd instance. echo "Etcd healthy - killing ${image} container" docker kill "${image}" elif [ "${ETCD_API}" == "etcd3" ]; then echo "Preparing etcd snapshot for restore" mkdir -p "${BACKUP_DIR}" echo "Copying data to ${BACKUP_DIR} and restoring there" number_files=$(find . -maxdepth 1 -type f -name "*.db" | wc -l) if [ "${number_files}" -ne "1" ]; then echo "Incorrect number of *.db files - expected 1" exit 1 fi mv *.db "${BACKUP_DIR}/" snapshot="$(ls ${BACKUP_DIR})" # Run etcdctl snapshot restore command and wait until it is finished. # setting with --name in the etcd manifest file and then it seems to work. docker run -v ${BACKUP_DIR}:/var/tmp/backup --env ETCDCTL_API=3 \ "k8s.gcr.io/etcd:${ETCD_VERSION}" /bin/sh -c \ "/usr/local/bin/etcdctl snapshot restore ${BACKUP_DIR}/${snapshot} --name ${NAME} --initial-cluster ${INITIAL_CLUSTER} --initial-advertise-peer-urls ${INITIAL_ADVERTISE_PEER_URLS}; mv /${NAME}.etcd/member /var/tmp/backup/" if [ "$?" -ne "0" ]; then echo "Docker container didn't started correctly" exit 1 fi rm -f "${BACKUP_DIR}/${snapshot}" fi # Also copy version.txt file. cp "${VERSION_FILE}" "${BACKUP_DIR}" export MNT_DISK="/mnt/disks/master-pd" # Save the corrupted data (clean directory if it is already non-empty). rm -rf "${MNT_DISK}/var/etcd-corrupted" mkdir -p "${MNT_DISK}/var/etcd-corrupted" echo "Saving corrupted data to ${MNT_DISK}/var/etcd-corrupted" mv /var/etcd/data "${MNT_DISK}/var/etcd-corrupted" # Replace the corrupted data dir with the restored data. echo "Copying restored data to /var/etcd/data" mv "${BACKUP_DIR}" /var/etcd/data if [ "${RESET_EVENT_ETCD:-}" == "true" ]; then echo "Removing event-etcd corrupted data" EVENTS_CORRUPTED_DIR="${MNT_DISK}/var/etcd-events-corrupted" # Save the corrupted data (clean directory if it is already non-empty). rm -rf "${EVENTS_CORRUPTED_DIR}" mkdir -p "${EVENTS_CORRUPTED_DIR}" mv /var/etcd/data-events "${EVENTS_CORRUPTED_DIR}" fi # Start etcd and kube-apiserver again. echo "Restarting etcd and apiserver from restored snapshot" mv "${MANIFEST_BACKUP_DIR}"/* "${MANIFEST_DIR}/" rm -rf "${MANIFEST_BACKUP_DIR}" # Verify that etcd is back. echo "Waiting for etcd to come back" if ! wait_for_etcd_up "${etcd_port}"; then echo "Etcd didn't come back correctly" exit 1 fi # Verify that event etcd is back. echo "Waiting for event etcd to come back" if ! wait_for_etcd_up "${event_etcd_port}"; then echo "Event etcd didn't come back correctly" exit 1 fi # Verify that kube-apiserver is back and cluster is healthy. echo "Waiting for apiserver to come back" if ! wait_for_cluster_healthy; then echo "Apiserver didn't come back correctly" exit 1 fi echo "Cluster successfully restored!"