runner-images VS checkout

Yeah this is a good option if you'd like something to deploy yourself! You can also build an AMI from GitHub's upstream image definition (https://github.com/actions/runner-images/tree/main/images/ub...) if you'd like it to match what's available in GitHub-hosted Actions.

With Depot, we're moving towards deeper performance optimizations and observability than vanilla GitHub runners - we've integrated the runners with a cache storage cluster for instance, and we're working on deeper integration with the compute platform that we built for distributed container image builds - as well as expanding the types of builds we can process beyond Actions and Docker, for instance.

But different options will be better for different folks, and the `philips-labs` project is good at what it does.

Whoa, there's a lot of stuff in there [1] that gets installed straight from vendors, without pinning content checksums to a value known-good to Github.

I get it, they want to have the latest versions instead of depending on how long Ubuntu (or, worse, Debian) package maintainers take to package stuff into their mainline repositories... but this attack surface is nuts.

[1] https://github.com/actions/runner-images/tree/main/images/ub...

I had a similar experience with ARC (actions-runner-controller).

One of the machines in the fleet failed to sync its clock via NTP. Once a job X got scheduled to it, the runner pod failed authentication due to incorrect clock time, and then the whole ARC system started to behave incorrectly: job X was stuck without runners, until another workflow job Y was created, and then X got run but Y became stuck. There were also other wierd behaviors like this so I eventually rebuilt everything based on VMs and stopped using ARC.

Using VMs also allowed me to support the use of the official runner images [0], which is good for compatibility.

I feel more people would benefit from managed "self-hosted" runners, so I started DimeRun [1] to provide cheaper GHA runners for people who don't have the time/willingness to troubleshoot low-level infra issues.

[0]: https://github.com/actions/runner-images

Reminds me: Still waiting for native ARM support on GitHub Actions https://github.com/actions/runner-images/issues/5631

Used https://github.com/actions/runner-images to get the packages needed for Ubuntu 22.04 As the packer requires a builder, I used "null" builder to set it as localhost ref: https://developer.hashicorp.com/packer/docs/builders/null (It was way difficult to figure it out the 1st time) I had to modify the .pkr.hcl file to pick my provisioners. I could not understand the use of /opt/hostedtoolcache folder (which I did later)

checkout

To checkout the merged commit with actions/checkout on pull_request_target event, you need to get the pull request by GitHub API and set the merge commit hash to actions/checkout input ref.

If you re-run GHA after master changes, CI is testing over different code.

You can [disable](https://github.com/actions/checkout#checkout-pull-request-head-commit-instead-of-merge-commit) on the checkout action:

```

There was an outage yesterday too when the GitHub action “checkout@v3” broke when they released “checkout@v4”

Yes, they broke the ability for GitHub CI to checkout repos…

https://github.com/actions/checkout/issues/1448

The first two steps are setting up the job's environment. The checkout action will checkout out the repository at the triggering ref. The setup-python action will setup the desired Python runtime. My package supports Python 3.9+ so I'm targeting the minimum version for my build environments.

These first few steps demonstrate how you can run commands like npm install or import other workflows such as how it uses the actions/checkout to copy the contents of the repository into a working directory on the runner host. Read Reusable workflows for more about the syntax for referencing them.

Check out the repo: We will use the actions/checkout action to checkout the repository.

Take a look at the checkout action usage here https://github.com/actions/checkout

Then, we have two important initial steps to define. The first one is an official GitHub Action used to check-out a repository so a workflow can access it. The second one it's pretty more complex but, briefly, downloads and set up a requested version of Java.