I’ve seen lots of teams trying to increase the availability of GitHub runners for their organization by implementing GitHub Actions Runner Controller (ARC). In some cases, they hope to try to exceed GitHub’s 99.9% SLA. Unfortunately, the math works against them. In this post, I’ll explain why.

One challenge with the GitHub’s Actions Runner Controller (ARC) is that it does not officially support Windows containers for the runners. With a little bit of work, though, it’s possible to make this configuration work on a hybrid Linux/Windows cluster.

Creating a well-organized build or release workflow is both an art and a science. Done properly, the process can be testable and maintainable, able to work on any CI/CD system. Like many things in software, there’s even a pattern that helps!

It’s not unusual for teams to want to merge the same branch into multiple branches. If they create multiple pull requests from that branch to each of the other branches, they suddenly find that their Checks behave differently than expected and the branches start to share results. Understanding why this happens makes it easy to get Checks to behave as expected.

Most package management systems support some kind of “universal artifacts” storage. Azure Artifacts supports “universal packages”, Artifactory supports “generic repositories”, and Nexus has “raw repositories”. But what about GitHub? From all appearances, it would seem this is an oversight. Although not explicitly documented, it turns out it’s fully supported.