Docker container upgrade script

containers.sh

#!/bin/bash

base=`basename $0`

get_image() {
  docker inspect --format='{{.Config.Image}}' $1
}

get_name() {
  NAME=`docker inspect --format='{{.Name}}' $1`
  echo ${NAME:1}
}

show_run_cmd() {
  NET_ARGS=`docker inspect --format='--net {{range $h, $conf := .NetworkSettings.Networks}}{{$h}}{{end}}' $1`
  PORT_ARGS=`docker inspect --format='{{range $p, $conf := .NetworkSettings.Ports}}-p {{(index $conf 0).HostPort}}:{{$p}} {{end}}' $1`
  IMAGE=`get_image $1`
  VOLUME_ARGS=`docker inspect --format='{{range $conf := .HostConfig.Binds}}-v {{$conf}} {{end}}' $1`
  CAPP_ADD_ARGS=`docker inspect --format='{{range $conf := .HostConfig.CapAdd}}--cap-add {{$conf}} {{end}}' $1`
  CAPP_DROP_ARGS=`docker inspect --format='{{range $conf := .HostConfig.CapDrop}}--cap-drop {{$conf}} {{end}}' $1`
  CAPP_ARGS=$CAPP_ADD_ARGS $CAPP_DROP_ARGS
  NAME_ARGS="--name `get_name $1`"
  RESTART_ARGS=`docker inspect --format='--restart {{.HostConfig.RestartPolicy.Name}}' $1`
  RUN_ARGS="-d $NAME_ARGS $RESTART_ARGS $NET_ARGS $PORT_ARGS $VOLUME_ARGS $CAPP_ARGS"
  echo docker run $RUN_ARGS $IMAGE
}

upgrade_containers() {
  for n in $(docker ps --format='{{.ID}}'); do
    RUN_CMD=`show_run_cmd $n`
    NAME=`get_name $n`
    IMAGE=`get_image $n`
    printf "Stopping $NAME..."; docker stop $n
    printf "Removing $NAME..."; docker rm $n
    printf "Pulling $IMAGE:latest"; docker pull $IMAGE:latest
    printf "Running $NAME..."; $RUN_CMD
  done
}

generate_script() {
  CREATE_SCRIPT=${1:-create_containers.sh}
  echo Generating $CREATE_SCRIPT...
  
  [ -f $CREATE_SCRIPT ] && mv $CREATE_SCRIPT $CREATE_SCRIPT.bak
  printf "#!/bin/bash\n\n" > $CREATE_SCRIPT

  for n in $(docker ps --format='{{.ID}}'); do
    RUN_CMD=`show_run_cmd $n`
    NAME=`get_name $n`
    printf "# Creating $NAME container\n$RUN_CMD\n\n" >> $CREATE_SCRIPT
  done
}

show_help() {
    echo "Usage: $base <command> [args]"
    echo "Commands:"
    echo "    --help                 Shows this help"
    echo "    generate [filename]    Generates container creation script"
    echo "    upgrade                Upgrades all running containers"
}

if [ $# -eq 0 ]; then
  show_help
fi 

while [ $# -gt 0 ];
do
  case $1 in
  "--help")
      show_help
      ;;
  "generate")
      shift
      generate_script $1
      ;;
  "upgrade")
      upgrade_containers
      ;;
  *)
      show_help
      ;;
  esac
  shift
done