Mastering Kubernetes - Second Edition

Assigning pods to the custom scheduler

OK. The custom scheduler is running alongside the default scheduler. But how does Kubernetes choose which scheduler to use when a pod needs scheduling? The answer is that the pod decides and not Kubernetes. The pod spec has an optional scheduler name field. If it's missing, the default scheduler is used; otherwise, the specified scheduler is used. This is the reason the custom scheduler names must be unique. The name of the default scheduler is default-scheduler, in case you want to be explicit in your pod spec. Here is a pod definition that will be scheduled using the default scheduler:

apiVersion: v1 kind: Pod metadata: name: some-pod labels: name: some-pod spec: containers: - name: some-container ...