file_upload.sh

#!/bin/sh -l

set -e

function fileUpload {
  TOKEN="${INPUT_TOKEN}"
  if [ -z "${TOKEN}" ]; then
    >&2 printf "\nERR: Invalid input: 'token' is required, and must be specified.\n"
    >&2 printf "\tNote: It's necessary to interact with Github's API.\n\n"
    >&2 printf "Try:\n"
    >&2 printf "\tuses: meeDamian/github-release@TAG\n"
    >&2 printf "\twith:\n"
    >&2 printf "\t  token: \${{ secrets.GITHUB_TOKEN }}\n"
    >&2 printf "\t  ...\n"
    exit 1
  fi

  # Try getting $TAG from action input
  TAG="${INPUT_TAG}"

  # [fallback] Try getting $TAG from ENVironment VARiable
  #   NOTE: Can be set in a step before using ex:
  #     echo ::set-env name=RELEASE_TAG::"v1.0.0"
  if [ -z "${TAG}" ]; then
    TAG="${RELEASE_TAG}"
  fi

  # [fallback] Try getting $TAG from Github context (only works on git-tag push action)
  if [ -z "${TAG}" ]; then
    TAG="$(echo "${GITHUB_REF}" | grep 'refs/tags/' | awk -F/ '{print $NF}')"
  fi

  # If all ways of getting the TAG failed, exit with an error
  if [ -z "${TAG}" ]; then
    >&2 printf "\nERR: Invalid input: 'tag' is required, and must be specified.\n"
    >&2 printf "Try:\n"
    >&2 printf "\tuses: meeDamian/github-release@TAG\n"
    >&2 printf "\twith:\n"
    >&2 printf "\t  tag: v0.0.1\n"
    >&2 printf "\t  ...\n\n"
    >&2 printf "Note: To use dynamic TAG, set RELEASE_TAG env var in a prior step, ex:\n"
    >&2 printf '\techo ::set-env name=RELEASE_TAG::"v1.0.0"\n\n'
    exit 1
  fi
INPUT_GZIP=false
  # Verify that gzip: option is set to any of the allowed values
  if [ "${INPUT_GZIP}" != "true" ] && [ "${INPUT_GZIP}" != "false" ] && [ "${INPUT_GZIP}" != "folders" ]; then
    >&2 printf "\nERR: Invalid input: 'gzip' can only be not set, or one of: true, false, folders\n"
    >&2 printf "\tNote: It defines what to do with assets before uploading them.\n\n"
    >&2 printf "Try:\n"
    >&2 printf "\tuses: meeDamian/github-release@TAG\n"
    >&2 printf "\twith:\n"
    >&2 printf "\t  gzip: true\n"
    >&2 printf "\t  ...\n"
    exit 1
  fi

  BASE_URL="https://api.github.com/repos/${GITHUB_REPOSITORY}/releases"

  #
  ## Check for Github Release existence
  #
  RELEASE_ID="$(curl -H "Authorization: token ${TOKEN}"  "${BASE_URL}/tags/${TAG}" | jq -r '.id | select(. != null)')"

  if [ -n "${RELEASE_ID}" ] && [ "${INPUT_ALLOW_OVERRIDE}" != "true" ]; then
    >&2 printf "\nERR: Release '%s' already exists, and overriding is not allowed.\n" "${TAG}"
    >&2 printf "\tNote: Either use different 'tag:' name, or 'allow_override:'\n\n"
    >&2 printf "Try:\n"
    >&2 printf "\tuses: meeDamian/github-release@TAG\n"
    >&2 printf "\twith:\n"
    >&2 printf "\t  ...\n"
    >&2 printf "\t  allow_override: true\n"
    exit 1
  fi

  # If no `name:` passed as input, but RELEASE_NAME env var is set, use it as the name
  if [ -z "${INPUT_NAME}" ] && [ -n "${RELEASE_NAME}" ]; then
    INPUT_NAME="${RELEASE_NAME}"
  fi

  #
  ## Create, or update release on Github
  #
  # For a given string return either `null` (if empty), or `"quoted string"` (if not)
  toJsonOrNull() {
    if [ -z "$1" ]; then
      echo null
      return
    fi

    if [ "$1" = "true" ] || [ "$1" = "false" ]; then
      echo "$1"
      return
    fi

    echo "\"$1\""
  }

  METHOD="POST"
  URL="${BASE_URL}"
  if [ -n "${RELEASE_ID}" ]; then
    METHOD="PATCH"
    URL="${URL}/${RELEASE_ID}"
  fi

  # Creating the object in a PATCH-friendly way
  CODE="$(jq -nc \
    --arg tag_name              "${TAG}" \
    --argjson target_commitish  "$(toJsonOrNull "${INPUT_COMMITISH}")"  \
    --argjson name              "$(toJsonOrNull "${INPUT_NAME}")"       \
    --argjson body              "$(toJsonOrNull "${INPUT_BODY}")"       \
    --argjson draft             "$(toJsonOrNull "${INPUT_DRAFT}")"      \
    --argjson prerelease        "$(toJsonOrNull "${INPUT_PRERELEASE}")" \
    '{$tag_name, $target_commitish, $name, $body, $draft, $prerelease} | del(.[] | nulls)' | \
    curl -s -X "${METHOD}" -d @- \
    --write-out "%{http_code}" -o "/tmp/${METHOD}.json" \
    -H "Authorization: token ${TOKEN}" \
    -H "Content-Type: application/json" \
    "${URL}")"

  if [ "${CODE}" != "200" ] && [ "${CODE}" != "201" ]; then
    >&2 printf "\n\tERR: %s to Github release has failed\n" "${METHOD}"
    >&2 jq < "/tmp/${METHOD}.json"
    exit 1
  fi

  RELEASE_ID="$(jq '.id' < "/tmp/${METHOD}.json")"

  #
  ## Handle, and prepare assets
  #
  # If no `files:` passed as input, but `RELEASE_FILES` env var is set, use it instead
  if [ -z "${INPUT_FILES}" ] && [ -n "${RELEASE_FILES}" ]; then
    INPUT_FILES="${RELEASE_FILES}"
  fi

  if [ -z "${INPUT_FILES}" ]; then
    >&2 echo "No assets to upload. All done."
    exit 0
  fi

  ASSETS="${HOME}/assets"

  mkdir -p "${ASSETS}/"

  # this loop splits files by the space
  for entry in $(echo "${INPUT_FILES}" | tr ' ' '\n'); do
    ASSET_NAME="${entry}"

    # Well, that needs explaining…  If delimiter given in `-d` does not occur in string, `cut` always returns
    #   the original string, no matter what the field `-f` specifies.
    #
    # I'm prepanding `:` to `${entry}` in `echo` to ensure match happens, because once it does, `-f` is respected,
    #   and I can easily check fields, and that way:
    #   * `-f 2` always contains the name of the asset
    #   * `-f 3` is either the custom name of the asset,
    #   * `-f 3` is empty, and needs to be set to `-f 2`
    ASSET_NAME="$(echo ":${entry}" | cut -d: -f2)"
    ASSET_PATH="$(echo ":${entry}" | cut -d: -f3)"

    if [ -z "${ASSET_PATH}" ]; then
      ASSET_NAME="$(basename "${entry}")"
      ASSET_PATH="${entry}"
    fi

    # this loop, expands possible globs
    for file in ${ASSET_PATH}; do
      # Error out on the only illegal combination: compression disabled, and folder provided
      if [ "${INPUT_GZIP}" = "false" ] && [ -d "${file}" ]; then
          >&2 printf "\nERR: Invalid configuration: 'gzip' cannot be set to 'false' while there are 'folders/' provided.\n"
          >&2 printf "\tNote: Either set 'gzip: folders', or remove directories from the 'files:' list.\n\n"
          >&2 printf "Try:\n"
          >&2 printf "\tuses: meeDamian/github-release@TAG\n"
          >&2 printf "\twith:\n"
          >&2 printf "\t  ...\n"
          >&2 printf "\t  gzip: folders\n"
          >&2 printf "\t  files: >\n"
          >&2 printf "\t    README.md\n"
          >&2 printf "\t    my-artifacts/\n"
          exit 1
      fi

      # Just copy files, if compression not enabled for all
      if [ "${INPUT_GZIP}" != "true" ] && [ -f "${file}" ]; then
        cp "${file}" "${ASSETS}/${ASSET_NAME}"
        continue
      fi

      # In any other case compress
      tar -cf "${ASSETS}/${ASSET_NAME}.tgz"  "${file}"
    done
  done

  # At this point all assets to-be-uploaded (if any), are in `${ASSETS}/` folder
  echo "Files to be uploaded to Github:"
  ls "${ASSETS}/"

  UPLOAD_URL="$(echo "${BASE_URL}" | sed -e 's/api/uploads/')"

  for asset in "${ASSETS}"/*; do
    FILE_NAME="$(basename "${asset}")"

    CODE="$(curl -sS  -X POST \
      --write-out "%{http_code}" -o "/tmp/${FILE_NAME}.json" \
      -H "Authorization: token ${TOKEN}" \
      -H "Content-Length: $(stat -c %s "${asset}")" \
      -H "Content-Type: $(file -b --mime-type "${asset}")" \
      --upload-file "${asset}" \
      "${UPLOAD_URL}/${RELEASE_ID}/assets?name=${FILE_NAME}")"

    if [ "${CODE}" -ne "201" ]; then
      >&2 printf "\n\tERR: Uploading %s to Github release has failed\n" "${FILE_NAME}"
      jq < "/tmp/${FILE_NAME}.json"
      exit 1
    fi
  done

  >&2 echo "All done."
}