Kubernetes Container Orchestration Networking Services 5

Question 1

What is the function of CoreDNS in a Kubernetes cluster?

Accepted Answer

Provides cluster-internal DNS resolution for Services and pods

Answer

CoreDNS runs as a Deployment in kube-system and resolves cluster-internal DNS names (e.g., ..svc.cluster.local) for pods.

Question 2

What DNS name format does Kubernetes use for Services within the same namespace?

Accepted Answer

..svc.cluster.local

Answer

The fully qualified DNS name for a Service is ..svc.cluster.local, though within the same namespace a short name also resolves.

Question 3

Which Kubernetes resource replaced Endpoints for improved scalability, especially in large clusters?

Accepted Answer

EndpointSlice

Answer

EndpointSlice shards endpoint data into smaller chunks (default 100 endpoints per slice), reducing the size of watch events and etcd load compared to monolithic Endpoints objects.

Question 4

What is the purpose of the service.kubernetes.io/topology-aware-hints annotation on a Service?

Accepted Answer

Hints to kube-proxy to prefer endpoints in the same zone as the client

Answer

Topology-aware hints instruct kube-proxy and EndpointSlice controllers to prefer routing traffic to endpoints in the same zone, reducing inter-zone data transfer costs.

Question 5

When a pod's dnsPolicy is set to None, what must the pod spec also provide?

Accepted Answer

A dnsConfig section with custom nameservers

Answer

A dnsPolicy of None means the pod ignores cluster DNS entirely, so the pod must supply a dnsConfig block with explicit nameservers and search domains.

Kubernetes Container Orchestration Practice Test

Kubernetes Container Orchestration Practice Test

Kubernetes Container Orchestration Networking Services 5