DevOps

Why ‘kubernetes’ service ?

Analysis:

kubectl describe svc kubernetes

Name:              kubernetes
Namespace:         default
Labels:            component=apiserver
                   provider=kubernetes
Annotations:       <none>
Selector:          <none>
Type:              ClusterIP
IP Family Policy:  SingleStack
IP Families:       IPv4
IP:                10.96.0.1
IPs:               10.96.0.1
Port:              https  443/TCP
TargetPort:        6443/TCP
Endpoints:         172.31.15.134:6443
Session Affinity:  None
Events:            <none>
  1. ‘kubernetes’ is a clusterIP service. (ie can be accessed only inside the cluster.)
  2. It has no selector specified.( So no automatic LB.)
  3. But endpoints specified(maybe hardcoded) as 172.31.15.134:6443 ( that means all the requests to this service will be routed to 172.31.15.134:6443)
  4. Now you can see the its the IP and port corresponding to APIServer pod.

Conclusion:

So kubernetes service act as a service for APIServer Pod.

Other pods inside the cluster like Scheduler, Controller etc, can use this service to communicate with APIServer pod.