Github Actions for Automatic Creation/Update Heroku review apps without connecting Github to Heroku and without app.json configuration

heroku-review-apps-create.yml

# please set up following github secrets in your repo:
# HEROKU_PIPELINE_NAME (https://devcenter.heroku.com/articles/pipelines#creating-pipelines)
# HEROKU_USER (your heroku username/email)
# HEROKU_API_KEY (use: 'heroku authorizations:create' for creating separate api_key for this purpose)

name: Heroku Review App Create

on:
  pull_request:
    types: opened
    branches:
      - 'main'

jobs:
  build:
    runs-on: ubuntu-latest
    timeout-minutes: 10

    env:
      HEROKU_PIPELINE_NAME: ${{secrets.HEROKU_PIPELINE_NAME}} # i.e: your-pipeline
      # here you can configure your desired app name format: https://your-pipeline-pr-1001.herokuapp.com
      HEROKU_APP_NAME: ${{secrets.HEROKU_PIPELINE_NAME}}-pr-${{ github.event.number }}
      HEROKU_REGION: eu # set your desired region here

    steps:
    - uses: actions/checkout@v2

    - name: "[Heroku] Setup credentials"
      env:
        HEROKU_USER: ${{ secrets.HEROKU_USER }}
        HEROKU_API_KEY: ${{ secrets.HEROKU_API_KEY }}
      run: envsubst < ./config/heroku/netrc > ~/.netrc

    - name: "[Heroku] Create review app"
      env:
        RAILS_MASTER_KEY: ${{ secrets.RAILS_MASTER_KEY }}
      run: |
        heroku apps:create ${HEROKU_APP_NAME} --region ${HEROKU_REGION}
        heroku config:add HEROKU_DEBUG_RAILS_RUNNER=1 RAILS_STAGE=staging RAILS_MASTER_KEY=${RAILS_MASTER_KEY} -a ${HEROKU_APP_NAME}
        heroku git:remote -a ${HEROKU_APP_NAME}

    - name: "[Heroku] Setup Addons"
      # set your addons here
      run: heroku addons:create heroku-postgresql:hobby-dev

    - name: "[Heroku] Add to pipeline"
      run: heroku pipelines:add ${HEROKU_PIPELINE_NAME} -a ${HEROKU_APP_NAME} -s staging

    - name: "[Heroku] Deploy"
      run: |
        git fetch origin ${{ github.head_ref }}:head
        git push heroku head:main

    - name: "[Heroku] Postdeploy"
      # Good place for one time setup i.e: loading schema and seeding db with test data
      run: heroku run rails db:setup