submodule-update.yml

name: Submodule update

on:
  schedule:
    - cron: '0 6 * * MON'
    
  workflow_dispatch:

jobs:
  check-and-update:

    runs-on: ubuntu-latest

    steps:
    - name: Checkout repository and submodule
      uses: actions/checkout@v2
      with:
        submodules: recursive
    
    - name: script
      run: |
        cd learnGitBranching
        if [ $(git rev-list HEAD...origin/main --count) != 0 ]; then
            echo 'Update pending'
            echo "REPO_DISPATCH=true" >> "$GITHUB_ENV"
        else
            echo 'Nothing to update'
            echo "REPO_DISPATCH=false" >> "$GITHUB_ENV"
            exit 0
        fi
        
        cd ..
        msg=$(git submodule update --remote)
        commitstr=$(echo $msg | grep -oP "checked out '\K\w+")
        git config --global user.name 'Git bot'
        git config --global user.email 'bot@noreply.github.com'
        git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}
        git commit -am "Auto updated submodule reference: pcottle/learnGitBranching@${commitstr}"
        git push
    - name: Repository Dispatch
      if: env.REPO_DISPATCH != 'false'
      uses: peter-evans/repository-dispatch@v1
      with:
        token: ${{ secrets.REPO_ACCESS_TOKEN }}
        repository: ${{ github.repository }}
        event-type: submodule-updated