Exposing the Service

Exposing the Service

For some parts of your applications you may want to expose a Service onto an external IP address. Kubernetes supports two ways of doing this: NodePort and LoadBalancer.

kubectl -n my-nginx get svc my-nginx

Output 


NAME       TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)   AGE
my-nginx   ClusterIP   10.100.225.196   <none>        80/TCP    33m

Currently the Service does not have an External IP, so let’s now patch the Service to use a cloud load balancer, by updating the type of the my-nginx Service from ClusterIP to LoadBalancer:

kubectl -n my-nginx patch svc my-nginx -p '{"spec": {"type": "LoadBalancer"}}'

We can check for the changes:

kubectl -n my-nginx get svc my-nginx

Output 


NAME       TYPE           CLUSTER-IP       EXTERNAL-IP                                                             PORT(S)        AGE
my-nginx   LoadBalancer   10.100.225.196   aca434079a4cb0a9961170c1-23367063.us-west-2.elb.amazonaws.com           80:30470/TCP   39m

The Load Balancer can take a couple of minutes in being available on the DNS.

Now, let’s try if it’s accessible.

export loadbalancer=$(kubectl -n my-nginx get svc my-nginx -o jsonpath='{.status.loadBalancer.ingress[*].hostname}')

curl -k -s http://${loadbalancer} | grep title

Output 


<title>Welcome to nginx!</title>

If the Load Balancer name is too long to fit in the standard kubectl get svc output, you’ll need to do kubectl describe service my-nginx to see it. You’ll see something like this:

kubectl -n my-nginx describe service my-nginx | grep Ingress

Output 


LoadBalancer Ingress:   a320587ffd19711e5a37606cf4a74574-1142138393.us-east-1.elb.amazonaws.com