services.md

Services

Create a pod nginx-clusterip with image nginx. Expose it as a ClusterIP service.

show

kubectl run nginx-clusterip --image=nginx --restart=Never --port=80 --expose

kubectl get service nginx-clusterip # verification
# NAME              TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
# nginx-clusterip   ClusterIP   10.104.163.30   <none>        80/TCP    6s

Create a pod nginx-nodeport with image nginx. Expose it as a NodePort service nginx-nodeport-svc

show

kubectl run nginx-nodeport --image=nginx --restart=Never --port=80
kubectl expose pod nginx-nodeport --name nginx-nodeport-svc --type NodePort --port 80 --target-port 80

OR

cat << EOF > nginx-nodeport.yaml
apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    run: nginx-nodeport
  name: nginx-nodeport-svc
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    run: nginx-nodeport
  type: NodePort
status:
  loadBalancer: {}
EOF

kubectl apply -f nginx-nodeport.yaml

# verification - port expose might change
kubectl get svc nginx-nodeport-svc
# NAME                 TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
# nginx-nodeport-svc   NodePort   10.106.55.131   <none>        80:31287/TCP   12s 

Create a deployment nginx-deployment with image nginx and 3 replicas. Expose it as a NodePort service nginx-deployment-svc on port 30080.

show

kubectl create deploy nginx-deployment --image nginx && kubectl scale deploy nginx-deployment --replicas 3
kubectl expose deployment nginx-deployment --type NodePort --port 80 --target-port 80 --dry-run=client -o yaml > nginx-deployment-svc.yaml

Edit nginx-deployment-svc.yaml to add nodePort: 30080 and apply kubectl apply -f nginx-deployment-svc.yaml

apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: nginx-deployment
  name: nginx-deployment
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
    nodePort: 30080 # add node port
  selector:
    app: nginx-deployment
  type: NodePort
status:
  loadBalancer: {}

# verification
kubectl get service nginx-deployment 
# NAME               TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
# nginx-deployment   NodePort   10.43.166.122   <none>        80:30080/TCP   38s

Clean up

# clean up 
kubectl delete service nginx-deployment nginx-nodeport-svc
kubectl delete deployment nginx-deployment nginx-nodeport