docker-pushmi-pullyu

#!/usr/bin/env bash
set -o errexit
set -o pipefail
set -o nounset
trap 'echo "$0: line $LINENO: exit status of last command: $?" >&2' ERR
trap 'cleanup' EXIT

usage() {
  echo "
Usage:	$0 [OPTIONS] [USER@]HOST NAME[:TAG] [NAME[:TAG]...]

Push images directly to a remote host (without a separate registry)

Options:
  -s, --ssh-opts string   Specify additional ssh arguments (e.g. --ssh-opts \"-i private.pem -C\")
  --no-cache              Do not use a cache for local registry images"
}

cleanup() {
  if [ -n "${registry_container_name-}" ] && docker ps -q -f name="$registry_container_name"
  then
    echo "Killing the local registry..."
    docker kill "$registry_container_name" >/dev/null || true
    docker rm "$registry_container_name" >/dev/null || true
  fi
}

flag-error() {
  local message="$1"
  echo "$message" >&2
  usage >&2
  exit 125
}

argument-error() {
  local message="$1"
  echo "$message" >&2
  usage >&2
  exit 1
}

wait-for() {
  local max_wait_seconds=5
  local start_time="$SECONDS"
  local exit_code

  while true
  do
    # Run the command being retried and capture the error code. This
    # awkward incantation ensures correct behavior even if the errexit
    # option is set.
    "$@" && exit_code="$?" || exit_code="$?"

    if [ "$exit_code" -eq 0 ] || [ $((SECONDS - start_time)) -ge "$max_wait_seconds" ]
    then
      break
    else
      sleep 0.1
    fi
  done

  return "$exit_code"
}

check-registry() {
  local registry="$1"
  # Check if the registry is up.
  docker login --username="AzureDiamond" --password="hunter2" "$registry" >/dev/null 2>&1
}

use_cache=true

args=""
while [ -n "${1+x}" ]
do
  case "$1" in
    -s|--ssh-opts|--ssh-opts=*)
      ssh_opts="${1##--ssh-opts=}"
      if [ "$ssh_opts" = "$1" ]
      then
        if [ "$#" -ge 2 ]
        then
          ssh_opts="$2"
          shift
        else
          ssh_opts=""
        fi
      fi
      if [ -z "$ssh_opts" ]
      then
        flag-error "flag needs an argument: $1"
      fi
      ;;
    --no-cache)
      use_cache=false
      ;;
    -*)
      flag-error "unknown flag: $1"
      ;;
    *)
      args="$args $1"
      ;;
  esac
  shift
done

eval set -- "$args"

if [ "$#" -lt 2 ]
then
  argument-error "\"$0\" requires at least 2 arguments."
fi

deploy_target="$1"
shift
image_names="$*"

# We need to connect via 127.0.0.1 specifically, otherwise docker tries to use TLS.
registry_host="127.0.0.1"

if [ "$use_cache" = true ]
then
  echo "Running a local registry..."
  docker volume create docker-pushmi-pullyu
  registry_container_name=$(
    docker run \
      --detach \
      --volume="docker-pushmi-pullyu:/var/lib/registry" \
      --publish-all \
      registry:2
  )
else
  echo "Running a local registry without using an image cache..."
  registry_container_name=$(
    docker run \
      --detach \
      --publish-all \
      registry:2
  )
fi

registry_port=$(
  docker inspect "$registry_container_name" --format='
    {{- range $entry := (index .NetworkSettings.Ports "5000/tcp") -}}
      {{- if eq $entry.HostIp "0.0.0.0" -}}
        {{- $entry.HostPort -}}
      {{- end -}}
    {{- end -}}
  '
)

wait-for check-registry "$registry_host:$registry_port"
echo "The local registry is now usable at $registry_host:$registry_port."

for source_image_name in $image_names
do
  echo "Pushing $source_image_name to $registry_host:$registry_port..."
  docker tag "$source_image_name" "$registry_host:$registry_port/$source_image_name"
  docker push "$registry_host:$registry_port/$source_image_name"
  docker rmi "$registry_host:$registry_port/$source_image_name"
done

# shellcheck disable=SC2086,SC2087
ssh -R "$registry_port:$registry_host:$registry_port" ${ssh_opts:-} "$deploy_target" sh <<EOF
  for target_image_name in $image_names
  do
    echo "Pulling \$target_image_name onto $deploy_target from $registry_host:$registry_port..."
    docker pull "$registry_host:$registry_port/\$target_image_name" \
      && docker tag "$registry_host:$registry_port/\$target_image_name" "\$target_image_name" \
      && docker rmi "$registry_host:$registry_port/\$target_image_name"
  done
EOF