Service types and selectors

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A Service gives traffic a stable destination while Pods change. Its selector matches Pod labels, and targetPort identifies the port the selected application listens on. The Service port is the port clients use. ClusterIP serves inside the cluster; NodePort also publishes a node listener; LoadBalancer requests an external load balancer from a supporting environment. A local simulator can inspect those declarations without provisioning a cloud resource. A Service name that resembles a Deployment name doesn't connect them automatically. In these tasks you define the type and routing fields, then repair a selector or target port that would send traffic to the wrong place.

printf '%s' 'apiVersion: "v1"
kind: "Service"
metadata:
  name: "cobalt-147"
spec:
  type: "ClusterIP"
  selector:
    app: "cobalt-147"
  ports:
    - port: 80
      targetPort: 80
' > 'workload.yaml'
kubectl apply -f workload.yaml

A Service selects Pod labels and forwards to targetPort. Its own name doesn't automatically connect it to a Deployment.

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