goliath.sh

#!/usr/bin/env bash

# A script to build and package Goliath.

set -euo pipefail

CRDB_SRC_DIR="cockroach-data"
CRDB_VOL_NAME="crdb_volume"
CRDB_VOL_MOUNT="/cockroach-data"
CRDB_DEST_DIR="."
BUILD_TIMESTAMP=$(date +%s)
BUILD_HASH=$(git rev-parse HEAD)

FORCE_VOL=false
ACTION=""
ATTACHED=false
DOCKER_COMPOSE_ARGS=()
ENV=prod

# Export variables to make them visible during the build process
export BUILD_TIMESTAMP
export BUILD_HASH

function usage() {
  echo "Usage: $0 [ACTION] [OPTION...] [-- [EXTRA_ARGS...]]"
  echo ""
  echo " ACTION must be \"up\" or \"down\"."
  echo ""
  echo "Options:"
  echo " -h, --help      Display this help message."
  echo " --env ENV       Environment to start (\"prod\", \"dev\", or \"debug\"). Default to \"prod\"."
  echo " --attached      Starts containers in attached mode. Only applies to \"up\" action."
  echo " --crdb_dir DIR  CockroachDB data directory to populate volume. Ignored if volume exists unless --force_volume is set."
  echo " --force_volume  Force creation of volume even if already exists (destroys existing volume)."
  echo ""
  echo " EXTRA_ARGS are passed to \"docker compose\"."
}

function handle_options() {
  ACTION="$1"
  if [[ ! "${ACTION}" =~ ^up|down$ ]]; then
    echo "ACTION must be set to one of {up, down}, got: ${ACTION}. Exiting."
    usage
    exit 1
  fi
  shift

  while [ $# -gt 0 ]; do
    case $1 in
      -h | --help)
        usage
        exit 0
        ;;
      --crdb_dir)
        CRDB_SRC_DIR="$2"
        if [[ -z "${CRDB_SRC_DIR}" ]]; then
          echo "Value of crdb dir flag must be non-empty. Exiting."
          exit 1
        fi
        if [[ ! -d "${CRDB_SRC_DIR}" ]]; then
          echo "Directory specified by crdb dir flag does not exist: ${CRDB_SRC_DIR}. Exiting."
          usage
          exit 1
        fi
        shift
        ;;
      --env)
        ENV="$2"
        if [[ ! "${ENV}" =~ ^debug|dev|prod$ ]]; then
          echo "--env must be set to one of {prod, dev, debug}, got: ${ENV}. Exiting."
          usage
          exit 1
        fi
        shift
        ;;
      --attached)
        ATTACHED=true
        ;;
      --force_volume)
        FORCE_VOL=true
        ;;
      --)
        shift
        DOCKER_COMPOSE_ARGS+=("$@")
        break
        ;;
      *)
        echo "Invalid option: $1" >&2
        usage
        exit 1
        ;;
    esac
    shift
  done
}

# Inspired by https://stackoverflow.com/a/68511611.
function copy_to_volume() {
  SRC_PATH=$1
  VOLUME_MOUNT=$2
  DEST_PATH=$3

  # Create minimal, empty container.
  echo -e 'FROM scratch\nLABEL empty=""' | docker build -t empty -

  CONTAINER_ID=$(docker container create -v "${VOLUME_MOUNT}" empty cmd)
  docker cp "${SRC_PATH}/" "${CONTAINER_ID}:${DEST_PATH}"
  docker rm "${CONTAINER_ID}" --volumes
}

function setup_volume() {
  if [[ $FORCE_VOL = true ]]; then
    echo "Destroying existing CockroachDB data volume: ${CRDB_VOL_NAME} ..."

    # Make sure all volumes referenced in the Compose file are downed.
    docker compose down --volumes
    # Then make sure any stopped containers in the Compose file are also removed.
    docker compose rm --volumes
    docker volume rm -f "${CRDB_VOL_NAME}" > /dev/null
  fi

  if [[ -z $(docker volume ls -f name="${CRDB_VOL_NAME}" -q) ]]; then
    docker volume ls -f name="${CRDB_VOL_NAME}" -q
    echo "Creating CockroachDB data volume..."
    exit 1

    docker volume create --name "${CRDB_VOL_NAME}" > /dev/null
    copy_to_volume \
        "${CRDB_SRC_DIR}" \
        "${CRDB_VOL_NAME}:${CRDB_VOL_MOUNT}" \
        "${CRDB_DEST_DIR}"
  fi
}

# Flag parsing.
handle_options "$@"

setup_volume

echo "Executing:"
echo "  Action: ${ACTION}"
echo "  Environment: ${ENV}"
echo "  Extra args: ${DOCKER_COMPOSE_ARGS[*]}"

if [[ "${ACTION}" = "up" ]]; then
  if [[ $ATTACHED = true ]]; then
    # If running in attached mode, down services on Ctrl-C.
    trap 'docker compose --profile ${ENV} down' INT
  else
    DOCKER_COMPOSE_ARGS+=("-d")
  fi
fi

docker compose --profile "${ENV}" "${ACTION}" "${DOCKER_COMPOSE_ARGS[@]}"