ClusterIP service type in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a ClusterIP service in Kubernetes?

A ClusterIP service exposes the service on an internal IP in the cluster. It is reachable only within the cluster and not from outside.

intermediate

How does a ClusterIP service route traffic to pods?

It uses kube-proxy to route requests sent to the ClusterIP to one of the backend pods selected by labels.

beginner

Which use case fits best for a ClusterIP service?

When you want to expose a service only inside the cluster, for example, for internal communication between microservices.

beginner

What is the default service type in Kubernetes if none is specified?

ClusterIP is the default service type if you do not specify any other type.

beginner

Can a ClusterIP service be accessed from outside the Kubernetes cluster?

No, ClusterIP services are only accessible inside the cluster. To access from outside, use NodePort or LoadBalancer types.

What does a ClusterIP service expose?

A An internal IP accessible only inside the cluster

B An external IP accessible from the internet

C A port on each node

D A load balancer IP

ClusterIP exposes an internal IP reachable only within the Kubernetes cluster.

Which Kubernetes service type allows external access by default?

A None

B ClusterIP

C Headless

D NodePort

NodePort exposes the service on a port on each node, allowing external access.

What is the default service type if none is specified in Kubernetes?

A LoadBalancer

B ClusterIP

C NodePort

D ExternalName

ClusterIP is the default service type in Kubernetes.

How does a ClusterIP service select which pods to send traffic to?

A By matching labels on pods

B Randomly without any selection

C By pod IP addresses only

D By node IP addresses

ClusterIP services use label selectors to route traffic to matching pods.

Can you access a ClusterIP service from outside the Kubernetes cluster?

A Yes, always

B No, never

C Only if you use port forwarding

D Only with LoadBalancer

ClusterIP services are internal, but you can access them externally using port forwarding or proxies.

Explain what a ClusterIP service is and when you would use it.

Think about services that do not need to be exposed outside the cluster.

Describe how Kubernetes routes traffic to pods using a ClusterIP service.

Focus on how the service finds the right pods to send requests to.