docker-util

#!/bin/bash

set -e

set_variables() {
  # define the full path to the docker binary
  DOCKER_BINARY="/usr/bin/docker"

  # define the full path to the 'zombie_dir_cleanup.py' script (see https://gist.github.com/mbentley/af9845a509b0166562b1)
  VOLUME_CLEANUP_SCRIPT="/usr/local/bin/zombie_dir_cleanup.py"
}

docker_group_check() {
  ### check to see if the user is either root or in the 'docker' group to see whether or not to use sudo
  if [ "$EUID" -eq 0 ] || [ $(groups | grep docker >/dev/null 2>&1; echo $?) -eq 0 ]
  then
    DOCKER_CMD="${DOCKER_BINARY}"
  else
    DOCKER_CMD="sudo ${DOCKER_BINARY}"
  fi
}

sudo_cache() {
  ### check to see if user is running root; if not, cache sudo credentials
  if [ "$EUID" -ne 0 ]
  then
    ### check to see if credentials are already cached
    if [ $(sudo -nv 2> /dev/null; echo $?) -eq 1 ]
    then
      echo "Running 'sudo true' to cache credentials"
      sudo true > /dev/null
    fi
  fi
}

compatibility_checks() {
  sudo_cache

  ### check to make sure the docker daemon is running
  if [[ $(${DOCKER_CMD} info >/dev/null 2>&1;echo $?) -eq 1 ]]
  then
    echo "error: docker daemon not running or insufficient privileges (do you have proper sudo access?)"
    exit 1
  fi

  ### check for 'apt-get' binary
  if [[ $(which apt-get > /dev/null; echo $?) -eq 1 ]]
  then
    echo "error: this script is designed to be used on systems that use APT"
    exit 1
  fi

  ### check for 'docker' binary
  if [ ! -f ${DOCKER_BINARY} ]
  then
    echo "error: docker binary (${DOCKER_BINARY}) is not present"
    exit 1
  fi
}

release_version() {
  ### get the 'release' version install from dpkg
  dpkg -l "lxc-docker-*" | grep "^ii" | awk '{print $2}' | awk -F '-' '{print $3}'
}

docker_version() {
  ### return the docker client version from the current binary
  ${DOCKER_CMD} version 2> /dev/null | grep --color=never 'Client version' | awk -F ':' '{ print $2 }' | tr -d ' '
}

docker_commit() {
  ### return the  git commit id from the current binary
  ${DOCKER_CMD} version 2> /dev/null | grep --color=never 'Git commit (client)' | awk -F ':' '{ print $2 }' | tr -d ' '
}

stop_docker_service() {
  ### stop the docker daemon
  echo -n "Stopping docker ($(docker_version) - $(docker_commit)) daemon..."
  sudo /etc/init.d/docker stop >/dev/null 2>&1 && echo "done"
}

start_docker_service() {
  ### start the docker daemon
  echo -n "Starting docker ($(docker_version) - $(docker_commit)) daemon..."
  sudo /etc/init.d/docker start >/dev/null 2>&1 && echo "done"
}

stop_containers() {
  ### get list of running containers
  CONTAINERS_RUNNING=$(${DOCKER_CMD} ps -q)

  ### stop running containers if there are any
  if [ -z "${CONTAINERS_RUNNING}" ]
  then
    echo "No running docker containers to stop"
  else
    echo "Stopping running docker containers:"
    ${DOCKER_CMD} stop ${CONTAINERS_RUNNING}
  fi
}

start_containers() {
  ### start previously running containers if there were any using list when they were stopped
  if [ -z "${CONTAINERS_RUNNING}" ]
  then
    echo "No previously running docker containers to start"
  else
    echo "Starting previously running docker containers:"
    ${DOCKER_CMD} start ${CONTAINERS_RUNNING}
  fi
}

cleanup_containers() {
  ### get list of containers that are in an 'exited' status
  REMOVABLE_CONTAINERS=$(${DOCKER_CMD} ps -f status=exited -q -a)

  ### if removablecontainers are in the list; remove them
  if [ -z "${REMOVABLE_CONTAINERS}" ]
  then
    echo "No stopped docker containers to remove"
  else
    echo "Removing stopped docker containers:"
    ${DOCKER_CMD} rm ${REMOVABLE_CONTAINERS}
  fi
}

cleanup_images() {
  ### get list of untagged images and remove them
  if [ $(${DOCKER_CMD} images | grep "^<none>" >/dev/null 2>&1; echo $?) -eq 0 ]
  then
    echo "Removing untagged docker images:"
    ${DOCKER_CMD} rmi $(${DOCKER_CMD} images | grep "^<none>" | awk '{print $3}')
  else
    echo "No untagged docker images to remove"
  fi
}

cleanup_volumes() {
  ### check for 'zombie_dir_cleanup.py' script
  if [ ! -f ${VOLUME_CLEANUP_SCRIPT} ]
  then
    echo "error: zombie_dir_cleanup.py script (${VOLUME_CLEANUP_SCRIPT}) is not present"
    echo "  see https://gist.github.com/mbentley/af9845a509b0166562b1"
    exit 1
  else
    sudo_cache
    ### run python script to cleanup volumes that have been orphaned
    sudo ${VOLUME_CLEANUP_SCRIPT}
  fi
}

backup_binary() {
  ### check to see if binary is a 'test', 'master', or 'release' version and backup accordingly
  if [ $(${DOCKER_CMD} version 2> /dev/null | grep 'Client version' | grep '\-dev' >/dev/null 2>&1; echo $?) -eq 0 ]
  then
    echo -n "Backing up 'docker' to 'docker.master'..."; sudo cp ${DOCKER_BINARY} ${DOCKER_BINARY}.master && echo "done"
  else
    if [ "$(release_version)" = "$(docker_version)" ]
    then
      echo -n "Backing up 'docker' to 'docker.release'...";sudo cp ${DOCKER_BINARY} ${DOCKER_BINARY}.release && echo "done"
    else
      echo -n "Backing up 'docker' to 'docker.test'...";sudo cp ${DOCKER_BINARY} ${DOCKER_BINARY}.test && echo "done"
    fi
  fi
}

cleanup_test_backup() {
  ### remove the 'test' binary backup if it exists
  if [ -f ${DOCKER_BINARY}.test ]
  then
    echo -n "Removing 'docker.test' backup..."; sudo rm ${DOCKER_BINARY}.test && echo "done"
  else
    echo "Nothing to cleanup"
  fi
}

cleanup_master_backup() {
  ### remove the 'master' binary backup if it exists
  if [ -f ${DOCKER_BINARY}.master ]
  then
    echo -n "Removing 'docker.master' backup..."; sudo rm ${DOCKER_BINARY}.master && echo "done"
  else
    echo "Nothing to cleanup"
  fi
}

cleanup_release_backup() {
  ### remove the 'release' binary backup if it exists
  if [ -f ${DOCKER_BINARY}.release ]
  then
    echo -n "Removing 'docker.release' backup..."; sudo rm ${DOCKER_BINARY}.release && echo "done"
  else
    echo "Nothing to cleanup"
  fi
}

install_test() {
  sudo_cache
  stop_containers
  stop_docker_service
  backup_binary
  ### check to see if a backup of 'test' exists; if it does, install it. otherwise, download a new copy
  if [ -f ${DOCKER_BINARY}.test ]
  then
    echo -n "Backup of 'test' available; installing backup file..."; sudo cp ${DOCKER_BINARY}.test ${DOCKER_BINARY} && echo "done"
  else
    echo "No backup of 'test' available; downloading and installing 'test' docker binary"
    sudo wget -q --show-progress -O ${DOCKER_BINARY} https://test.docker.com/builds/Linux/x86_64/docker-latest && sudo chmod 755 ${DOCKER_BINARY}
    backup_binary
  fi
  start_docker_service
  start_containers
}

upgrade_test() {
  sudo_cache
  stop_containers
  stop_docker_service
  cleanup_test_backup
  echo "Downloading and installing new 'test' docker binary"
  sudo wget -q --show-progress -O ${DOCKER_BINARY} https://test.docker.com/builds/Linux/x86_64/docker-latest && sudo chmod 755 ${DOCKER_BINARY}
  backup_binary
  start_docker_service
  start_containers
}

install_master() {
  sudo_cache
  stop_containers
  stop_docker_service
  backup_binary
  ### check to see if a backup of 'master' exists; if it does, install it. otherwise, download a new copy
  if [ -f ${DOCKER_BINARY}.master ]
  then
    echo -n "Backup of 'master' available; installing backup file..."; sudo cp ${DOCKER_BINARY}.master ${DOCKER_BINARY} && echo "done"
  else
    echo "No backup of 'master' available; downloading and installing 'master' docker binary"
    sudo wget -q --show-progress -O ${DOCKER_BINARY} https://master.dockerproject.com/linux/amd64/docker && sudo chmod 755 ${DOCKER_BINARY}
    backup_binary
  fi
  start_docker_service
  start_containers
}

upgrade_master() {
  sudo_cache
  stop_containers
  stop_docker_service
  cleanup_master_backup
  echo "Downloading and installing new 'master' docker binary"
  sudo wget -q --show-progress -O ${DOCKER_BINARY} https://master.dockerproject.com/linux/amd64/docker && sudo chmod 755 ${DOCKER_BINARY}
  backup_binary
  start_docker_service
  start_containers
}

install_release() {
  sudo_cache
  stop_containers
  backup_binary
  ### check to see if a backup of 'release' exists; if it does, install it. otherwise, re-install the currently installed debian package
  if [ -f ${DOCKER_BINARY}.release ]
  then
    stop_docker_service
    echo -n "Backup of 'release' available; installing backup file..."; sudo cp ${DOCKER_BINARY}.release ${DOCKER_BINARY} && echo "done"
    start_docker_service
  else
    echo "No backup of 'release' available; installing 'release' binary via apt"
    sudo apt-get install --reinstall -q -y $(dpkg -l "lxc-docker-*" | grep "^ii" | awk '{print $2}')
    backup_binary
  fi
  start_containers
}

upgrade_release() {
  sudo_cache
  stop_containers
  cleanup_release_backup
  echo "Current docker version: $(docker_version) - $(docker_commit)"
  echo "Installing new 'release' binary via apt"
  sudo apt-get install -qq --reinstall -y lxc-docker
  echo "New docker version: $(docker_version) - $(docker_commit)"
  backup_binary
  start_containers
}

main(){
  SCRIPT=$(basename $0)
  UTIL=${1:-help}
  CMD=${2:-}

  set_variables
  docker_group_check

  case ${UTIL}:${CMD} in
    cleanup:containers)
      compatibility_checks
      cleanup_containers
      ;;
    cleanup:images)
      compatibility_checks
      cleanup_images
      ;;
    cleanup:volumes)
      compatibility_checks
      cleanup_volumes
      ;;
    cleanup:all)
      compatibility_checks
      cleanup_containers
      cleanup_images
      cleanup_volumes
      ;;
    cleanup:*)
      echo "Usage: ${SCRIPT} cleanup {all|containers|images|volumes}"
      exit 1
      ;;
    install:test)
      compatibility_checks
      install_test
      ;;
    install:master)
      compatibility_checks
      install_master
      ;;
    install:release)
      compatibility_checks
      install_release
      ;;
    install:*)
      echo "Usage: ${SCRIPT} install {test|master|release}"
      exit 1
      ;;
    upgrade:test)
      compatibility_checks
      upgrade_test
      ;;
    upgrade:master)
      compatibility_checks
      upgrade_master
      ;;
    upgrade:release)
      compatibility_checks
      upgrade_release
      ;;
    upgrade:*)
      echo "Usage: ${SCRIPT} upgrade {test|master|release}"
      exit 1
      ;;
    *:*)
      echo "Usage: ${SCRIPT} cleanup {all|containers|images|volumes}"
      echo "Usage: ${SCRIPT} install {test|master|release}"
      echo "Usage: ${SCRIPT} upgrade {test|master|release}"
      exit 1
      ;;
  esac

  echo "done."
}

main "$@"