name: Set README on GitHub

# Trigger this workflow every 12 hours.
on:
  push:
    branches:
      - "**"

jobs:
  rewrite_readme:
    name: Append header on README
    runs-on: ubuntu-latest
    if: contains(github.server_url, 'github.com')
    permissions:
      contents: write
    steps:
      - name: Write header
        run: |
          cp README.md __OLD.md
          echo "> This repository is a mirror of [repo.katenary.io](https://repo.katenary.io/katenary/katenary)" > README.md
          echo >> README.md
          cat __OLD.md >> README.md
      - name: Commit
        uses: EndBug/add-and-commit@v9
        with:
          add: README.md
          message: "Add mirror information"
          push: true