"Writing a Kubernetes Cluster Autoscaler Provider with externalgrpc" by Marco De Luca, VSHN AG

The Kubernetes Cluster Autoscaler decides when to scale, but it doesn't know how to create a VM. That's the cloud provider's job, and the upstream tree covers mostly big clouds. With externalgrpc, you can plug virtually any cloud into the autoscaler over gRPC. This talk first looks at how the Cluster Autoscaler works under the hood and where the cloud provider fits in. Then we walk through implementing one for a Swiss IaaS provider as an out-of-tree gRPC service: the design choices, the parts of the contract that matter, and the gotchas you only find by reading the autoscaler source. By the end, you'll know how to attach autoscaling to a cloud that isn't on the upstream list. Marco De Luca is a software/infrastructure engineer at VSHN AG. He spends most of his time on Kubernetes platforms, developer tooling, and making sure things don't break at 3 AM. At mdnix.io, he writes about infrastructure, Linux, Kubernetes, and the things he builds along the way. When he's not behind a terminal, he's somewhere in the Alps with his camera or having a private jam session with his guitar.