Endpoints

Part of the Introduction to Kubernetes section of Coddy's Terminal journey. Lesson 19 of 45.

How does a Service know which Pods to send traffic to? Through a label selector. kubectl expose copies the Deployment's labels (app=web) into the Service, and every Pod carrying those labels becomes a target.

The current list of targets is the Service's endpoints: the IP and port of every ready Pod behind it.

kubectl get endpoints web

Scale the Deployment and the endpoints follow. A Pod that is not ready is left out, so traffic only goes where it can be served.

kubectl describe service web shows both sides of the picture: the Selector the Service uses and the Endpoints it currently found. A Service with no endpoints usually means its selector matches no Pods.

Challenge

Beginner

Create a Deployment named web from the nginx image with 2 replicas, expose it on port 80, then list the endpoints of the web Service to see both Pod addresses.

Try it yourself

Terminal