How to run GitHub Actions locally

#webdev #fullstack #github #devops

This week, I made an update in our codebase that required a few changes in tests. I fixed them, tested locally and everything was fine. Proud of my accomplishment, I opened a PR, only to see that the tests started failing when running inside the GitHub Action.

I could have committed a bunch of log messages to the failing tests to find the cause of the issue but that seemed too tedious and I didn't want my coworkers to be able to see all my console.log('do we get here?') either. So, to maintain the appearance that I am a capable developer, I configured GitHub Actions locally and here is how:

I installed act https://nektosact.com/ - I used Brew
You need Docker, so the actions can run inside a container. I had Rancher already installed
(optional) install the "GitHub Local Actions" extension if you are using VSCode or Cursor and prefer a UI

I was using cursor and after installing everything, I could see the required components were installed and running and the extension did already detect my workflows:

When starting the GitHub Actions with the extension, I got the following error: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

To solve this, I just copied the command that the extension creates and added a DOCKER_HOST env variable in front, like so:

DOCKER_HOST=$(docker context inspect --format '{{.Endpoints.docker.Host}}') act --workflows ".github/workflows/backend.yaml" --secret-file "" --var-file "" --input-file "" --eventpath ""

To run just one simple job and not the whole workflow (maybe you don't need to lint right now) you just add a --job option:

DOCKER_HOST=$(docker context inspect --format '{{.Endpoints.docker.Host}}') act --workflows ".github/workflows/backend.yaml" --job "test" --secret-file "" --var-file "" --input-file "" --eventpath ""

The output was quite large in my case, so I redirected everything into log.txt, asked Cursor to go over it for me and find the critical error messages

This way, I found the issue quickly and looked like a hacker in the process. Hope this helps you too.