k8s dns checker

README.md

To verify if the DNS service is normal in a Kubernetes cluster. We can deploy a simple service to diagnose this:

$ kubectl apply -f nginx.yaml
$ kubectl exec -it web-0 sh # enter web-0 pod to resolve the other two pods domain name.
/ # nslookup web-1.nginx
/ # nslookup web-2 nginx

nginx.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: nginx
  serviceName: nginx
  replicas: 3
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.11-alpine
---
apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx