README.md

Kubernetes Service

A service is an abstract way to expose an application running on a set of Pods as a network service. With Kubernetes you don’t need to modify your application to use an unfamiliar service discovery mechanism. Kubernetes gives Pods their own IP addresses and a single DNS name for a set of Pods, and can load-balance across them.

Lets first create a simple deployment -

kubectl run nginx --image=nginx 

We will now use the deployment nginx to create service resource on top of it

A service can be created either using a YAML file or by using the kubectl utility

Cluster IP

vi service.yaml 

apiVersion: v1
kind: Service
metadata:
  name: nginx-clusterip
spec:
  selector:
    run: nginx
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
  type: ClusterIP

OR

kubectl expose deploy nginx --port=80 --type=ClusterIP --name=nginx-clusterip

NodePort

vi service-nodeport.yaml

apiVersion: v1
kind: Service
metadata:
  name: nginx-nodeport
spec:
  selector:
    app: MyApp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
  type: NodePort

OR

kubectl expose deploy nginx --port=80 --type=NodePort --name=nginx-nodeport

LoadBalancer (Only on top of cloud providers)

vi service-lb.yaml

apiVersion: v1
kind: Service
metadata:
  name: nginx-lb
spec:
  selector:
    app: MyApp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
  type: LoadBalancer

OR

kubectl expose deploy nginx --port=80 --type=LoadBalancer --name=nginx-lb

To view the services use the kubectl get service command

--external-ip flag

kubectl run nginx --image=nginx
kubectl expose pod nginx --external-ip={Routable IP address of your VM} --port=80 --target-port=80