automated_release.yml

name: AutomatedRelease

# Controls when the workflow will run
on: 
  push:
  # Triggers the workflow on push or pull request events but only for the master branch
    branches:
      - master
    paths:
      - '.version'
  pull_request:
    branches:
      - master
    paths: '.version'
  workflow_dispatch:
# A workflow run is made up of one or more jobs that can run sequentially or in parallel
jobs:
  # This workflow contains a single job called "build"
  build:
    # The type of runner that the job will run on
    runs-on: ubuntu-latest
    # Steps represent a sequence of tasks that will be executed as part of the job
    steps:
      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
      - name: Checkout
        uses: "actions/checkout@v2"
        with:
          fetch-depth: 0
      # Runs a set of commands using the runners shell
      - name: Get previous release tag
        id: previous-release
        run: |
             REF=$(git rev-list --tags --max-count=1 --skip=0 --no-walk)
             LASTTAG=$(git describe --tags $REF)
             echo "LASTTAG: $LASTTAG"
             echo "LASTTAG=$LASTTAG" >> $GITHUB_ENV
      - name: Get current version
        run: |
             VER=$(cat '.version')
             echo "VERSION=$VER" >> $GITHUB_ENV
      - name: Get Changelog
        id: changelog
        # get a changelog from git since last tag.
        # this is a multi line string therefore the syntax with GITHUB_ENV
        run: |
                CHANGELOG=$(git log $(git describe --tags --abbrev=0 ${{ env.LASTTAG }})..HEAD --no-merges --oneline)
                echo "$CHANGELOG"
                echo "CHANGELOG<<EOF" >> $GITHUB_ENV
                echo "$CHANGELOG" >> $GITHUB_ENV
                echo "EOF" >> $GITHUB_ENV
      - name: Create Release
        uses: ncipollo/release-action@v1
        with:
          token: "${{ secrets.GITHUB_TOKEN }}"
          tag: ${{ env.VERSION }}
          prerelease: false
          name: "phylociraptor v${{ env.VERSION }}"
          body: |
                Changes since last release:
                ${{ env.CHANGELOG }}