Optimizing Parallel Jobs in a Github Workflow

This weekend I was trying to optimize a GitHub Actions workflow composed of three primary steps: build, preview, and test. I really wanted the build step to be followed by the in preview and test steps in parallel. My first thought was to use the actions/cache action to persist the workspace between jobs, but there was a little more boilerplate than I wanted because I didn’t need to cache between different workflow runs, only jobs for a particular commit.

So I created a new action with two child actions jpoehnelt/reusable-workspace/save and jpoehnelt/reusable-workspace/restore to simplify the process.

The usage looks like the following.

name: CI
on:
  pull_request:
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      # Build steps (save should be after this)
      - uses: jpoehnelt/reusable-workspace/save@v1
  preview:
    needs: [build]
    runs-on: ubuntu-latest
    steps:
      - uses: jpoehnelt/reusable-workspace/restore@v1
      # Additional steps (restore should be before this)
  test:
    needs: [build]
    runs-on: ubuntu-latest
    steps:
      - uses: jpoehnelt/reusable-workspace/restore@v1
        with:
          fail-on-miss: true
      # Additional steps (restore should be before this)

My workflow now runs the build and then the preview and test steps in parallel. The preview job can also use a matrix without needing to rebuild the workspace after this change.

This new action is a great way to optimize your GitHub Actions workflows and reduce the time it takes to run your CI/CD pipeline. I hope you find it useful, just include the following:

- uses: jpoehnelt/reusable-workspace/restore@v1
- uses: jpoehnelt/reusable-workspace/save@v1