GitHub action to automatically rebase PRs

After installation simply comment /rebase to trigger the action:

Installation

To configure the action simply add the following lines to your .github/workflows/rebase.yml workflow file:

on: 
  issue_comment:
    types: [created]
name: Automatic Rebase
jobs:
  rebase:
    name: Rebase
    if: github.event.issue.pull_request != '' && contains(github.event.comment.body, '/rebase')
    runs-on: ubuntu-latest
    steps:
    - name: Checkout the latest code
      uses: actions/checkout@v2
      with:
        fetch-depth: 0
    - name: Automatic Rebase
      uses: cirrus-actions/rebase@1.3.1
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Restricting who can call the action

It's possible to use author_association field of a comment to restrict who can call the action and skip the rebase for others. Simply add the following expression to the if statement in your workflow file: github.event.comment.author_association == 'MEMBER'. See documentation for a list of all available values of author_association.