Kubernetes Pod Node Selector and Tolerations
This example demonstrates how to use nodeSelector and tolerations to control where a Pod is scheduled in Kubernetes.
Node Selector
The nodeSelector field allows you to specify labels that the node must have to be considered for scheduling.
Tolerations
tolerations allow Pods to be scheduled onto nodes with taints that would normally prevent them from being scheduled.
Example
# https://medium.com/kubernetes-tutorials/learn-how-to-assign-pods-to-nodes-in-kubernetes-using-nodeselector-and-affinity-features-e62c437f3cf8
apiVersion: v1
kind: Pod
metadata:
name: debug-pod
namespace: default
spec:
containers:
- name: debug
image: alpine
imagePullPolicy: IfNotPresent
command: ["sleep"]
args: ["100000"]
nodeSelector:
node: cpu
tolerations:
- key: application
operator: Equal
value: myapp
effect: NoSchedule
This Pod will only be scheduled on nodes with the label node: cpu and tolerates nodes with a taint of application=myapp:NoSchedule.