Virtual Clusters in the Real World: Lessons from k3k’s Journey to Production

on YouTube ↗37m

" summary

k3k is a production-ready virtual cluster implementation that ships three modes: k3s nested control planes for strong isolation, an agentless shared mode that mirrors workloads into the host cluster, and a tech-preview hosted control plane that decouples API servers and external worker nodes. It uses k3s, endpoint slices to connect external nodes, and sysbox/kata runtime sandboxes to avoid privileged pods, adds auto-generated network policies, exposed storage-class mapping, fixes PVC race conditions, passes conformance tests, and is still running scale tests.

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" chapters (10)

1. 0:00Introduction and journey
2. 2:15Problem of multi-tenancy
3. 7:11Virtual clusters concept
4. 9:20K3k architecture modes
5. 12:54Isolation challenges
6. 18:39Security improvements
7. 22:15Networking and storage issues
8. 26:53Scaling and releases
9. 29:59Live demo of HCP mode
10. 32:51Community feedback and Q&A

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