dokku/plugins/docker-options/docker-args-deploy

#!/usr/bin/env bash
set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x

docker_args() {
  declare desc="docker args plugin trigger"
  local trigger="$0"
  local STDIN=$(cat)
  local APP="$1"; local IMAGE_SOURCE_TYPE="$2"

  case "$0" in
    *docker-args-build)
      local PHASE=BUILD
      ;;
    *docker-args-deploy)
      local PHASE=DEPLOY
      ;;
    *docker-args-run)
      local PHASE=RUN
      ;;
  esac

  local FILE_PREFIX="DOCKER_OPTIONS_"
  local PHASE_FILE_PATH="${DOKKU_ROOT}/${APP}/${FILE_PREFIX}${PHASE}"

  local output=""

  if [[ -f "$PHASE_FILE_PATH" ]]; then
    local DONE=false
    until $DONE; do
      local line
      read -r line || local DONE=true

      [[ ! -n "$line" ]] && continue

      # shellcheck disable=SC1001
      case "$line" in
        \#*)
          continue
          ;;
        *)
          case "$IMAGE_SOURCE_TYPE" in
            dockerfile)
              case "$line" in
                --link*|-v*)
                  continue
                  ;;

                *)
                  local output="$output $line"
                  ;;
                esac
              ;;

            herokuish)
              case "$line" in
                --file*|--build-args*)
                  continue
                  ;;

                *)
                  local output="$output $line"
                  ;;
                esac
              ;;

            *)
              local output="$output $line"
              ;;
          esac
          ;;
      esac
    done < "$PHASE_FILE_PATH"
  fi

  echo -n "$STDIN$output"
}

docker_args "$@"