d

#!/usr/bin/env bash

# Docker utilities - d

set -o errexit

declare self dockerreg app package user repository
self=$(basename "$0")
dockerreg=https://docker.pkg.github.com

# Helper functions -----------------------------------------------------

check_cf_version() {
  if ! cf --version | grep -q "version 6"; then
    echo cf version 6 is required
    exit 1
  fi
}

usage() {
  cat <<EOF
Usage: $self <options> <action>

with options:
-a | --app <app location>
-p | --package <package name>
-u | --user <GitHub user>
-r | --repository <GitHub repository>

with actions:
login: login to GitHub Packages
build: create the Docker image (needs -a, -p, -u and -r)
run: run a container locally based on the image (needs -p, -u and -r)
publish: publish the image to GitHub (needs -p, -u and -r)
EOF
}

tagname() {
  echo "docker.pkg.github.com/$user/$repository/$package:latest"
}

checkval() {
  while (( $# )); do
    if [[ -z "$1" ]]; then
      usage
      exit 1
    fi
    shift
  done
}

# Action functions -----------------------------------------------------

login() {
  local user pass
  echo Authenticating with GitHub Packages
  read -r -p "Enter username: " user
  read -r -s -p "Enter password / token: " pass
  echo
  echo -n "$pass" \
    | docker login $dockerreg \
      --username "$user" \
      --password-stdin
}

build() {
  checkval "$app" "$package" "$user" "$repository"
  echo Building image for "$app"
  docker build \
    -t "$(tagname)" \
    -f ./Dockerfile \
    "$app"
}

run() {
  checkval "$package" "$user" "$repository"
  local port=${PORT:-5000}
  echo Running detached instance of image locally
  docker run \
    -d \
    -p "$port:$port" \
    "$(tagname)"
}

publish() {
  checkval "$package" "$user" "$repository"
  echo Publishing image to GitHub Packages
  docker push \
    "$(tagname)"
}

# Main function --------------------------------------------------------

main() {
  local action
  local arg
  if [[ $# -eq 0 ]]; then
    usage
    exit 1
  fi
  while (( $# )); do
    arg=$1
    case $arg in
      -a|--app)
        shift
        app=$1
        ;;
      -p|--package)
        shift
        package=$1
        ;;
      -u|--user)
        shift
        user=$1
        ;;
      -r|--repository)
        shift
        repository=$1
        ;;
      login|build|run|publish)
        action=$arg
        shift $(( $# - 1 ))
        ;;
      *)
        usage
        exit 1
        ;;
    esac
    shift
  done

  if [[ -z "$action" ]]; then
    usage
    exit 1
  fi

  $action

}

# Execution start ------------------------------------------------------

check_cf_version
main "$@"