Use Files From Another Repo

Background

While I was trying to implement a workflow that templates an automatic PR comment from a Markdown file, I stumbled upon an issue where I couldn't call my .md file which was supposed to sit in anothr repo. We have a dedicated repository that holds all of our reusable Github Workflows, which we then reference in each of our services as needed. If I simply put my Markdown file in the same repo as our reusable workflows, the file would not be found when some repo calls this workflow.

Example

The following would only work if test.md was located in the caller repo:

name: PR Welcome Comment
on:
  workflow_call:

jobs:
  comment:
    runs-on: ubuntu-latest
    steps:
    - name: Checkout repository
      uses: actions/checkout@v4

    - name: Read .md file and set output
      shell: bash
      run: |
        echo 'README<<EOF' >> $GITHUB_ENV
        cat ./test.md >> $GITHUB_ENV
        echo 'EOF' >> $GITHUB_ENV

    - name: Comment on PR
      uses: peter-evans/create-or-update-comment@v2
      with:
        issue-number: ${{ github.event.pull_request.number }}
        body: ${{ env.README }}
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Workaround

In the reusable workflow, we can create 2 files:

• Composite
• Github Action

Create the composite workflow using the same logic:

name: pr-comment
description: pr-comment

runs:
  using: "composite"
  steps:
    - name: Get markdown file
      shell: bash
      run: |
        echo 'README<<EOF' >> $GITHUB_ENV
        cat ${{ github.action_path }}/test.md >> $GITHUB_ENV
        echo 'EOF' >> $GITHUB_ENV

And then call it like so in the reusable workflow:

reusable-wf.yaml

name: PR Welcome Comment
on:
  workflow_call:

jobs:
  comment:
    runs-on: ubuntu-latest
    steps:
    - name: Fetch Markdown
      uses: dbeilin/PrimateCI/composite/common/pr-comment@main

    - name: Comment on PR
      uses: peter-evans/create-or-update-comment@v2
      with:
        issue-number: ${{ github.event.pull_request.number }}
        body: ${{ env.README }}

note

Both files should sit inside the "reusable" repo.

Calling the Workflow

You can now call the workflow like so in any of your repos:

caller-wf.yaml

name: common-trigger

on:
  pull_request:
    branches: [main]
    types: [opened, edited, synchronize, reopened]

jobs:
  pr-comment:
    name: pr-comment
    uses: dbeilin/PrimateCI/.github/workflows/pr.yml@main
    if: ${{ github.event_name == 'pull_request' && github.event.action == 'opened' }}

This way, you don't have to keep a .md file in your regular repos and it can sit along your reusable workflows. That's it 😎