#!/bin/sh # # The docker HA resource agent creates and launches a docker container # based off a supplied docker image. Containers managed by this agent # are both created and removed upon the agent's start and stop actions. # # Copyright (c) 2014 David Vossel # All Rights Reserved. # # This program is free software; you can redistribute it and/or modify # it under the terms of version 2 of the GNU General Public License as # published by the Free Software Foundation. # # This program is distributed in the hope that it would be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. # # Further, this software is distributed without any warranty that it is # free of the rightful claim of any third person regarding infringement # or the like. Any license provided herein, whether implied or # otherwise, applies only to this software file. Patent licenses, if # any, provided herein do not apply to combinations of this program with # other software, or any other product whatsoever. # # You should have received a copy of the GNU General Public License # along with this program; if not, write the Free Software Foundation, # Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. # ####################################################################### # Initialization: : ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat} . ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs # Parameter defaults OCF_RESKEY_reuse_default="0" : ${OCF_RESKEY_reuse=${OCF_RESKEY_reuse_default}} ####################################################################### meta_data() { cat < 1.0 The docker HA resource agent creates and launches a docker container based off a supplied docker image. Containers managed by this agent are both created and removed upon the agent's start and stop actions. Docker container resource agent. The docker image to base this container off of. docker image The name to give the created container. By default this will be that resource's instance name. docker container name Allow the image to be pulled from the configured docker registry when the image does not exist locally. NOTE, this can drastically increase the time required to start the container if the image repository is pulled over the network. Allow pulling non-local images Add options to be appended to the 'docker run' command which is used when creating the container during the start action. This option allows users to do things such as setting a custom entry point and injecting environment variables into the newly created container. Note the '-d' option is supplied regardless of this value to force containers to run in the background. NOTE: Do not explicitly specify the --name argument in the run_opts. This agent will set --name using either the resource's instance or the name provided in the 'name' argument of this agent. run options Specify a command to launch within the container once it has initialized. run command A comma separated list of directories that the container is expecting to use. The agent will ensure they exist by running 'mkdir -p' Required mount points Specify the full path of a command to launch within the container to check the health of the container. This command must return 0 to indicate that the container is healthy. A non-zero return code will indicate that the container has failed and should be recovered. If 'docker exec' is supported, it is used to execute the command. If not, nsenter is used. Note: Using this method for monitoring processes inside a container is not recommended, as containerd tries to track processes running inside the container and does not deal well with many short-lived processes being spawned. Ensure that your container monitors its own processes and terminates on fatal error rather than invoking a command from the outside. monitor command Kill a container immediately rather than waiting for it to gracefully shutdown force kill Allow the container to be reused once it is stopped. By default, containers get removed once they are stopped. Enable this option to have the particular one persist when this happens. reuse container Query the builtin healthcheck of docker (v1.12+) to determine health of the container. If left empty or set to false it will not be used. The healthcheck itself has to be configured within docker, e.g. via HEALTHCHECK in Dockerfile. This option just queries in what condition docker considers the container to be and lets ocf do its thing accordingly. Note that the time a container is in "starting" state counts against the monitor timeout. This is an additional check besides the standard check for the container to be running, and the optional monitor_cmd check. It doesn't disable or override them, so all of them (if used) have to come back healthy for the container to be considered healthy. use healthcheck END } ####################################################################### REQUIRE_IMAGE_PULL=0 docker_usage() { cat </dev/null 2>&1; then out=$(docker exec ${CONTAINER} $OCF_RESKEY_monitor_cmd 2>&1) rc=$? else out=$(echo "$OCF_RESKEY_monitor_cmd" | nsenter --target $(docker inspect --type=container --format {{.State.Pid}} ${CONTAINER}) --mount --uts --ipc --net --pid 2>&1) rc=$? fi if [ $rc -eq 127 ]; then ocf_log err "monitor cmd failed (rc=$rc), output: $out" ocf_exit_reason "monitor_cmd, ${OCF_RESKEY_monitor_cmd} , not found within container." # there is no recovering from this, exit immediately exit $OCF_ERR_ARGS elif [ $rc -ne 0 ]; then ocf_exit_reason "monitor cmd failed (rc=$rc), output: $out" rc=$OCF_ERR_GENERIC else ocf_log debug "monitor cmd passed: exit code = $rc" fi return $rc } container_exists() { local err err=$(docker inspect --type=container $CONTAINER 2>&1 >/dev/null) if [ $? -ne $OCF_SUCCESS ]; then case $err in *"No such container"*) # Return failure instead of exiting if container does not exist return 1 ;; *) # Exit if error running command ocf_exit_reason "$err" exit $OCF_ERR_GENERIC ;; esac fi return $OCF_SUCCESS } remove_container() { if ocf_is_true "$OCF_RESKEY_reuse"; then # never remove the container if we have reuse enabled. return 0 fi container_exists if [ $? -ne 0 ]; then # don't attempt to remove a container that doesn't exist return 0 fi ocf_log notice "Cleaning up inactive container, ${CONTAINER}." ocf_run docker rm $CONTAINER } docker_simple_status() { local val if [ ! -x "$(command -v docker)" ]; then ocf_log err "docker is not installed on this host" return $OCF_ERR_INSTALLED fi # let's first check if the daemon is up and running. VERSION_OUT=$(docker version) version_ret=$? if [ $version_ret -eq 1 ]; then ocf_exit_reason "Docker service is in error state while checking for ${CONTAINER}, based on image, ${OCF_RESKEY_image}: ${VERSION_OUT}" return $OCF_ERR_GENERIC fi container_exists if [ $? -ne 0 ]; then return $OCF_NOT_RUNNING fi # retrieve the 'Running' attribute for the container val=$(docker inspect --type=container --format {{.State.Running}} $CONTAINER 2>/dev/null) if [ $? -ne 0 ]; then #not running as a result of container not being found return $OCF_NOT_RUNNING fi if ocf_is_true "$val"; then # container exists and is running return $OCF_SUCCESS fi return $OCF_NOT_RUNNING } docker_health_status() { if ocf_is_true "$OCF_RESKEY_query_docker_health"; then local val container_exists if [ $? -ne 0 ]; then return $OCF_NOT_RUNNING fi # retrieve the 'Health' attribute for the container # This is a bash-style do-while loop to wait until instance is started. # if starting takes longer than monitor timeout then upstream will make this fail. while val=$(docker inspect --type=container --format {{.State.Health.Status}} $CONTAINER 2>/dev/null) if [ $? -ne 0 ]; then #not healthy as a result of container not being found return $OCF_NOT_RUNNING fi test "$val" = "starting" do sleep 1 done if [ "$val" = "healthy" ]; then # container exists and is healthy return $OCF_SUCCESS fi return $OCF_NOT_RUNNING fi return 0 } docker_monitor() { local rc=0 docker_simple_status rc=$? if [ $rc -ne 0 ]; then return $rc fi docker_health_status rc=$? if [ $rc -ne 0 ]; then return $rc fi monitor_cmd_exec } docker_create_mounts() { oldIFS="$IFS" IFS="," for directory in $OCF_RESKEY_mount_points; do mkdir -p "$directory" done IFS="$oldIFS" } docker_start() { docker_create_mounts local run_opts="-d --name=${CONTAINER}" # check to see if the container has already started docker_simple_status if [ $? -eq $OCF_SUCCESS ]; then return $OCF_SUCCESS fi if [ -n "$OCF_RESKEY_run_opts" ]; then run_opts="$run_opts $OCF_RESKEY_run_opts" fi if [ $REQUIRE_IMAGE_PULL -eq 1 ]; then ocf_log notice "Beginning pull of image, ${OCF_RESKEY_image}" docker pull "${OCF_RESKEY_image}" if [ $? -ne 0 ]; then ocf_exit_reason "failed to pull image ${OCF_RESKEY_image}" return $OCF_ERR_GENERIC fi fi if ocf_is_true "$OCF_RESKEY_reuse" && container_exists; then ocf_log info "starting existing container $CONTAINER." ocf_run docker start $CONTAINER else # make sure any previous container matching our container name is cleaned up first. # we already know at this point it wouldn't be running remove_container ocf_log info "running container $CONTAINER for the first time" ocf_run docker run $run_opts $OCF_RESKEY_image $OCF_RESKEY_run_cmd fi if [ $? -ne 0 ]; then ocf_exit_reason "docker failed to launch container" return $OCF_ERR_GENERIC fi # wait for monitor to pass before declaring that the container is started while true; do docker_simple_status if [ $? -ne $OCF_SUCCESS ]; then ocf_exit_reason "Newly created docker container exited after start" return $OCF_ERR_GENERIC fi monitor_cmd_exec if [ $? -eq $OCF_SUCCESS ]; then ocf_log notice "Container $CONTAINER started successfully" return $OCF_SUCCESS fi ocf_exit_reason "waiting on monitor_cmd to pass after start" sleep 1 done } docker_stop() { local timeout=60 docker_simple_status ret=$? if [ $ret -eq $OCF_NOT_RUNNING ]; then remove_container return $OCF_SUCCESS elif [ $ret -eq $OCF_ERR_GENERIC ]; then return $OCF_ERR_GENERIC fi if [ -n "$OCF_RESKEY_CRM_meta_timeout" ]; then timeout=$((($OCF_RESKEY_CRM_meta_timeout/1000) -10 )) if [ $timeout -lt 10 ]; then timeout=10 fi fi if ocf_is_true "$OCF_RESKEY_force_kill"; then ocf_run docker kill $CONTAINER else ocf_log debug "waiting $timeout second[s] before killing container" ocf_run docker stop -t=$timeout $CONTAINER fi if [ $? -ne 0 ]; then ocf_exit_reason "Failed to stop container, ${CONTAINER}, based on image, ${OCF_RESKEY_image}." return $OCF_ERR_GENERIC fi remove_container if [ $? -ne 0 ]; then ocf_exit_reason "Failed to remove stopped container, ${CONTAINER}, based on image, ${OCF_RESKEY_image}." return $OCF_ERR_GENERIC fi return $OCF_SUCCESS } image_exists() { # if no tag was specified, use default "latest" local COLON_FOUND=0 local SLASH_FOUND=0 local SERVER_NAME="" local IMAGE_NAME="${OCF_RESKEY_image}" local IMAGE_TAG="latest" SLASH_FOUND="$(echo "${OCF_RESKEY_image}" | grep -o '/' | grep -c .)" if [ ${SLASH_FOUND} -ge 1 ]; then SERVER_NAME="$(echo ${IMAGE_NAME} | cut -d / -f 1-${SLASH_FOUND})" IMAGE_NAME="$(echo ${IMAGE_NAME} | awk -F'/' '{print $NF}')" fi COLON_FOUND="$(echo "${IMAGE_NAME}" | grep -o ':' | grep -c .)" if [ ${COLON_FOUND} -ge 1 ]; then IMAGE_TAG="$(echo ${IMAGE_NAME} | awk -F':' '{print $NF}')" IMAGE_NAME="$(echo ${IMAGE_NAME} | cut -d : -f 1-${COLON_FOUND})" fi # IMAGE_NAME might be following formats: # - image # - repository:port/image # - docker.io/image (some distro will display "docker.io/" as prefix) docker images | awk '{print $1 ":" $2}' | egrep -q -s "^(docker.io\/|${SERVER_NAME}\/)?${IMAGE_NAME}:${IMAGE_TAG}\$" if [ $? -eq 0 ]; then # image found return 0 fi if ocf_is_true "$OCF_RESKEY_allow_pull"; then REQUIRE_IMAGE_PULL=1 ocf_log notice "Image (${OCF_RESKEY_image}) does not exist locally but will be pulled during start" return 0 fi # image not found. return 1 } docker_validate() { check_binary docker if [ -z "$OCF_RESKEY_image" ]; then ocf_exit_reason "'image' option is required" exit $OCF_ERR_CONFIGURED fi if [ -n "$OCF_RESKEY_monitor_cmd" ]; then docker exec --help >/dev/null 2>&1 if [ ! $? ]; then ocf_log info "checking for nsenter, which is required when 'monitor_cmd' is specified" check_binary nsenter fi fi image_exists if [ $? -ne 0 ]; then ocf_exit_reason "base image, ${OCF_RESKEY_image}, could not be found." exit $OCF_ERR_CONFIGURED fi return $OCF_SUCCESS } # TODO : # When a user starts plural clones in a node in globally-unique, a user cannot appoint plural name parameters. # When a user appoints reuse, the resource agent cannot connect plural clones with a container. if ocf_is_true "$OCF_RESKEY_CRM_meta_globally_unique"; then if [ -n "$OCF_RESKEY_name" ]; then if [ -n "$OCF_RESKEY_CRM_meta_clone_node_max" ] && [ "$OCF_RESKEY_CRM_meta_clone_node_max" -ne 1 ] then ocf_exit_reason "Cannot make plural clones from the same name parameter." exit $OCF_ERR_CONFIGURED fi if [ -n "$OCF_RESKEY_CRM_meta_master_node_max" ] && [ "$OCF_RESKEY_CRM_meta_master_node_max" -ne 1 ] then ocf_exit_reason "Cannot make plural master from the same name parameter." exit $OCF_ERR_CONFIGURED fi fi : ${OCF_RESKEY_name=`echo ${OCF_RESOURCE_INSTANCE} | tr ':' '-'`} else : ${OCF_RESKEY_name=${OCF_RESOURCE_INSTANCE}} fi if [ -n "$OCF_RESKEY_container" ]; then # we'll keep the container attribute around for a bit in order not to break # any existing deployments. The 'name' attribute is prefered now though. CONTAINER=$OCF_RESKEY_container ocf_log warn "The 'container' attribute is depreciated" else CONTAINER=$OCF_RESKEY_name fi case $__OCF_ACTION in meta-data) meta_data exit $OCF_SUCCESS;; start) docker_validate docker_start;; stop) docker_stop;; monitor) docker_monitor;; validate-all) docker_validate;; usage|help) docker_usage exit $OCF_SUCCESS ;; *) docker_usage exit $OCF_ERR_UNIMPLEMENTED ;; esac rc=$? ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION : $rc" exit $rc