What does this program do?

It parses yaml file with v1.List (made of nodes) OR --- separated v1.Nodes into []*v1.Node.

v1.List made of nodes:

apiVersion: v1
items:
- apiVersion: v1
  kind: Node
  metadata:
    ...
    name: kind-control-plane
    ...
  spec:
    ...
- apiVersion: v1
  kind: Node
  metadata:
    ...
    name: kind-worker
    ...
  spec:
    ...
kind: List
metadata:
  resourceVersion: ""

Check node-templates-list.yaml for an actual example.

--- separated v1.Nodes

apiVersion: v1
kind: Node
metadata:
  ...
  name: kind-control-plane
  ...
spec:
  ...
---

apiVersion: v1
kind: Node
metadata:
  ...
  name: kind-worker
  ...
spec:
  ...

Check node-templates-non-list.yaml for an actual example.

Output

With node-templates-non-list.yaml

$ go run main.go
node kind-control-plane
node kind-worker

With node-templates-list.yaml

$ go run main.go
node kind-control-plane
node kind-worker
node kind-worker2

Why

• This is a PoC to read in template nodes for kwok provider in Kubernetes cluster-autoscaler. Check kubernetes/autoscaler#5820

References

• decoding --- separated objects: kubernetes/client-go#193 (comment)
• decoding node objects: kubernetes/client-go#193 (comment)
• decoding RawExtension: kubernetes/apimachinery#102
• converting runtime.Object to v1.Node: kubernetes/client-go#401 (comment)
• creating multi-node kind cluster: https://mcvidanagama.medium.com/set-up-a-multi-node-kubernetes-cluster-locally-using-kind-eafd46dd63e5