k8s service basic - service selector

 what happens if your service selector doesn't match any of your deployment/pod label? 

There won't be any endpoints visbile

In terms of selector, either one match would be sufficient. For example, this is your deployment label

 template:

    metadata:

      labels:

        app: httpbin

        version: v1

        apptype: backend

So your service selector, just need to be either one: 

spec:

  ports:

  - name: http

    port: 8000

    targetPort: 80

  selector:

    #app: httpbin

    #apptype: backend

    version: v1

The same applies to deployment resources.