Auto-release new TYPO3 extensions from github to TER (TYPO3 Extension Repository) when they are tagged via REST API

Introduction.txt

Github actions gives you the possibility to run some code after a special trigger (e.g. a push into a repo) is recognized.
This can be used for running tests or - in our case - to deploy the software to TYPO3 TER when a new tag is pushed.

1) First of all, you should login on extensions.typo3.org and create some access token (API Token) to use the new REST API of typo3.org
to publish your extensions (see https://github.com/TYPO3/tailor#prerequisites for some more help on this).

2) After that you can add three secret tokens in your github repository 
(see https://docs.github.com/en/free-pro-team@latest/actions/reference/encrypted-secrets#creating-encrypted-secrets-for-an-environment for some more details):
TYPO3_API_USERNAME (your username for FE-login on typo3.org)
TYPO3_API_PASSWORD (your password for FE-login on typo3.org)
TYPO3_API_TOKEN (see 1)
Those secrets can be used as environment variable now.

3) Just add .github/workflows/ter-release.yml (see below) to your repository. Update line 13 and 14 with your configuration.

4) That's it :)

Inspired from:
https://github.com/TYPO3/tailor/blob/main/README.md
https://www.felixnagel.com/blog/artikel/2020/06/23/automated-typo3-ter-releases-using-github-actions/

Used in extension lux: https://github.com/in2code-de/lux

ter-release.yml

name: TER release

on:
  push:
    tags:
      - '*'

jobs:
  ter-release:
    name: TER release
    runs-on: ubuntu-latest
    env:
      TYPO3_EXTENSION_KEY: 'lux'
      REPOSITORY_URL: 'https://github.com/in2code-de/lux'
      TYPO3_API_TOKEN: ${{ secrets.TYPO3_API_TOKEN }}
      TYPO3_API_USERNAME: ${{ secrets.TYPO3_API_USERNAME }}
      TYPO3_API_PASSWORD: ${{ secrets.TYPO3_API_PASSWORD }}

    steps:
      - name: Get the version
        id: get_version
        run: echo ::set-output name=VERSION::${GITHUB_REF/refs\/tags\//}

      - name: Setup PHP
        uses: shivammathur/setup-php@v2
        with:
          php-version: '7.4'
          extensions: intl, mbstring, xml, soap, zip, curl

      - name: Install EXT:tailor
        run: composer global require typo3/tailor --prefer-dist --no-progress --no-suggest

      - name: Upload EXT:${{ env.EXTENSION_KEY }} as ${{ steps.get_version.outputs.VERSION }} to TER
        run: php ~/.composer/vendor/bin/tailor ter:publish ${{ steps.get_version.outputs.VERSION }} --artefact=${{ env.REPOSITORY_URL }}/archive/${{ steps.get_version.outputs.VERSION }}.zip --comment="New release of version ${{ steps.get_version.outputs.VERSION }} - see details, changelog and documentation on ${{ env.REPOSITORY_URL }}"