swift-lambda

#!/bin/bash

ProgName=$(basename $0)

swift_lambda_env=".swift-lambda.env"
swift_lambda_workdir=".swift-lambda"
swift_lambda_build_path="${swift_lambda_workdir}/build"
swift_lambda_bin_path="${swift_lambda_workdir}/bin"
swift_lambda_lib_path="${swift_lambda_workdir}/lib"
swift_lambda_cp_swift_deps="${swift_lambda_workdir}/cp_swift_deps"
swift_lambda_bootstrap="${swift_lambda_workdir}/bootstrap"

sub_help(){
    echo "Usage: $ProgName <subcommand> [options]"
    echo "Subcommands:"
    echo "    init      Initialize a new function"
    echo "    run       Invokes the function"
    echo "    archive   Build and archive the function for deployment"
    echo "    version   Print version information and exit"
    echo ""
    echo "For help with each subcommand run:"
    echo "$ProgName <subcommand> -h|--help"
    echo ""
}

sub_init(){
  case $1 in
    "" | "-h" | "--help")
        echo "Usage: $ProgName init [ARGS...]"
        echo "Arguments:"
        echo "    name  Provide custom function name"
        echo ""
        ;;
    *)

        if [ -d ${1} ]; then
          echo "A directory named ${1} already exists."
          exit 1;
        fi

        mkdir -p ${1}
        swift package --package-path ${1} init --name ${1} --type executable

        # Package.swift template
        package_path=${1}/Package.swift
        package_dependency_template='// .package(url: /\* package url \*/, from: "1.0.0"),'
        package_dependency='.package(url: "https://github.com/tonisuter/aws-lambda-swift.git", from: "0.1.0")'
        sed -i '' "s|${package_dependency_template}|${package_dependency}|" ${package_path}

        package_dependency_template='dependencies: \[\]),'
        package_dependency='dependencies: \["AWSLambdaSwift"\]),'
        sed -i '' "s|${package_dependency_template}|${package_dependency}|" ${package_path}

        # main.swift template
        cat << EOF > ${1}/Sources/${1}/main.swift
import AWSLambdaSwift

func handler(input: JSONDictionary, context: Context) throws -> JSONDictionary {
  return ["status": 200]
}

let runtime = try Runtime()
runtime.registerLambda("handler", handlerFunction: handler)
try runtime.start()

EOF

        # .swift-lambda template
        cat << EOF > ${1}/${swift_lambda_env}
SWIFT_LAMBDA_EXECUTABLE=${1}
SWIFT_LAMBDA_BUILD_DOCKER_IMAGE="swift:5.0"
SWIFT_LAMBDA_PRE_BUILD_OPTIONS=""
SWIFT_LAMBDA_BUILD_OPTIONS="-c release"

EOF

  esac
}

build(){

  if [ ! -f Package.swift ]; then
    echo "Manifest Package.swift not found. Please run swift-lambda from your project's root directory."
    exit 1;
  fi

  echo "Using [${swift_lambda_env}] configuration:"

  set -o allexport
  source ${swift_lambda_env}
  set +o allexport

  echo "SWIFT_LAMBDA_EXECUTABLE=${SWIFT_LAMBDA_EXECUTABLE}"
  echo "SWIFT_LAMBDA_BUILD_DOCKER_IMAGE=${SWIFT_LAMBDA_BUILD_DOCKER_IMAGE}"
  echo "SWIFT_LAMBDA_PRE_BUILD_OPTIONS=${SWIFT_LAMBDA_PRE_BUILD_OPTIONS}"
  echo "SWIFT_LAMBDA_BUILD_OPTIONS=${SWIFT_LAMBDA_BUILD_OPTIONS}"

  rm -rf ${swift_lambda_bin_path}
  rm -rf ${swift_lambda_lib_path}
  mkdir -p ${swift_lambda_bin_path}
  mkdir -p ${swift_lambda_lib_path}

  # cp_swift_deps
  cat << EOF > ${swift_lambda_cp_swift_deps}
#!/bin/bash
BIN="\${1}"
OUTPUT="\${2}"
DEPS=\$(ldd \$BIN | awk 'BEGIN{ORS=" "}\$1\
  ~/^\//{print \$1}\$3~/^\//{print \$3}'\
  | sed 's/,\$/\n/')

cp \$DEPS \$OUTPUT

EOF

  # bootstrap
  cat << EOF > ${swift_lambda_bootstrap}
#!/bin/sh
EXECUTABLE=\$LAMBDA_TASK_ROOT/bin/"\$(echo \$_HANDLER | cut -d. -f1)"
/var/task/lib/ld-linux-x86-64.so.2 --library-path /var/task/lib \${EXECUTABLE}

EOF

  chmod +x ${swift_lambda_cp_swift_deps}
  chmod +x ${swift_lambda_bootstrap}

  if [ -z "${SWIFT_LAMBDA_PRE_BUILD_OPTIONS}" ]; then
    swift_lambda_build_cmd="swift build"
  else
    swift_lambda_build_cmd="${SWIFT_LAMBDA_PRE_BUILD_OPTIONS} && swift build"
  fi

  docker run --rm -v $(pwd):/app --workdir /app ${SWIFT_LAMBDA_BUILD_DOCKER_IMAGE} bash -c \
		"${swift_lambda_build_cmd} --build-path ${swift_lambda_build_path} ${SWIFT_LAMBDA_BUILD_OPTIONS} \
			&& cp ${swift_lambda_build_path}/release/${SWIFT_LAMBDA_EXECUTABLE} /app/${swift_lambda_bin_path}/${SWIFT_LAMBDA_EXECUTABLE} \
			&& /app/${swift_lambda_cp_swift_deps} /app/${swift_lambda_bin_path}/${SWIFT_LAMBDA_EXECUTABLE} ${swift_lambda_lib_path}"
}

sub_archive(){
  build
  rm -rf "${SWIFT_LAMBDA_EXECUTABLE}.zip"
  cd ${swift_lambda_workdir}
  zip -r ../${SWIFT_LAMBDA_EXECUTABLE} bootstrap bin lib
  cd ..
}

sub_run(){
  case $1 in
    "" | "-h" | "--help")
        echo "Usage: $ProgName run [ARGS...]"
        echo "Arguments:"
        echo "    event   Lambda function input event [example: '{\"some\": \"event\"}']"
        echo ""
        ;;
    *)

        build
        docker run \
          --rm \
          -v $(pwd)/${swift_lambda_workdir}:/var/task \
          lambci/lambda:provided \
          ${SWIFT_LAMBDA_EXECUTABLE}.handler $1

  esac
}

sub_version(){
  echo "Swift-lambda version 0.2.0"
}

subcommand=$1
case $subcommand in
    "" | "-h" | "--help")
        sub_help
        ;;
    *)
        shift
        sub_${subcommand} $@
        if [ $? = 127 ]; then
            echo "Error: '$subcommand' is not a known subcommand." >&2
            echo "       Run '$ProgName --help' for a list of known subcommands." >&2
            exit 1
        fi
        ;;
esac