Scheduling a pod to a particular node using node-affinity #

This image shows you what you should expect when testing this scenario. You can follow the step-by-step guide after seeing this.

Prerequisites #

KWOK must be installed on the machine. See installation.
Install kubectl

Create cluster #

kwokctl create cluster

View clusters #

This ensures that the cluster was created successfully.

kwokctl get clusters

Create nodes #

kwokctl scale node --replicas 2

Label node-000000

kubectl label node node-000000 region=us-west-2

Scheduling process #

Step 1: Deploy pod #

The pod has a node affinity configured with a key value of region=eu-west-2. This matches the label on node-000000.

pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: pod-1
  namespace: default
  labels:
    region: us-west-2
spec:
  containers:
  - name: fake-container
    image: fake-image
    ports:
    - containerPort: 80
  tolerations:
  - key: "kwok.x-k8s.io/node"
    operator: "Exists"
    effect: "NoSchedule"
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: region
            operator: In
            values:
            - us-west-2

kubectl apply -f pod.yaml

Step 2: View the node the pod is scheduled to. #

kubectl get pod -o wide

Pod 1 is scheduled to node-000000.

Delete the cluster #

kwokctl delete cluster

Conclusion #

This example demonstrates how to use KWOK to simulate a scheduling scenario based on node affinity policy.