Kubernoodles

Kubernoodles is a reference architecture to demonstrate a lot of “how to securely devops” things, mostly for actions-runner-controller within a larger business. This is how I’ve built and maintain my demo environment.

Why I’ve made certain design choices is based on experiences shared below:

• Thoughts on self-hosted architecture
• Considerations on containerizing CI at an enterprise scale
• Securely using actions-runner-controller

Here’s what has been done and where we’re going.

1. Initial cluster setup - Kubernetes cluster setup in a managed provider, installing cilium and hubble to power observability, and actions-runner-controller with default runners in a scaling set.
2. Testing runner scalability - Create a few Actions to test, scale, and debug our self-hosted runners.
3. What are your users really doing? - Dive into understanding what’s being run in our self-hosted GitHub Actions runners with eBPF and tetragon .
4. Continuous delivery for custom runners - Setup the Kubernetes cluster, GitHub, and actions-runner-controller to work together, then make a GitHub Actions workflow to create and remove test deployments from a Helm chart.
5. Building custom runner images - How to build your own custom images for actions-runner-controller!
6. Building containers in ARC with Kaniko - Using Kaniko in actions-runner-controller to build containers without privileged pods.
7. Continuous integration for custom runner images - CI for your CI, or how to test your custom runner images on each change.
8. Writing tests for Actions runners - Test your enterprise CI images with the same rigor as your other software.
9. Reducing your software vulnerabilities - Reduce the number of CVEs in your runner images using wolfi to improve the security posture and eliminate many compliance headaches in regulated environments.
10. Building multi-architecture runners - Why not use ARM too? Adding extra CPU architectures to our runner image builds was easy.

Last updated in November 2024 with the updated versions of Kubernetes, actions-runner-controller, etc. that I am currently using.

Maybe soon:

• Log streaming
• More fun with eBPF
• File caching
• Fun with metrics!

My environment uses mostly on-prem resources and now almost always is used to build other software or demonstrate other parts of Kubernetes management. I used to have more access to Azure services, so there’s a lot of references there as well. I’ll try to call out using vanilla k8s as much as possible for portability.