Endpoints and endpoint slices in Kubernetes - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Difference between Endpoints and EndpointSlices

Which statement correctly describes the difference between Kubernetes Endpoints and EndpointSlices?

A Endpoints are used only for headless services, while EndpointSlices are used only for ClusterIP services.

B Endpoints store all IP addresses of pods for a service in a single object, while EndpointSlices split these addresses into multiple smaller objects for scalability.

C Endpoints automatically balance traffic, but EndpointSlices require manual load balancing configuration.

D Endpoints are deprecated and replaced by Services, while EndpointSlices are deprecated and replaced by Ingress.

💡 Hint

Think about how Kubernetes manages large numbers of pod IPs for a service.

Endpoints collect all pod IPs in one object, which can become large and inefficient. EndpointSlices split these IPs into smaller objects to improve scalability and performance.

💻 Command Output

intermediate

Output of kubectl get endpointslice command

What is the output of the following command if a service named webapp has 3 pods running?

kubectl get endpointslice -l kubernetes.io/service-name=webapp

A

NAME           ADDRESS-TYPE   PORTS
webapp-abcde   IPv6           443

B

NAME           ADDRESS-TYPE   PORTS
webapp-abcde   IPv4           80
webapp-abcde   IPv4           80
webapp-abcde   IPv4           80

C

NAME           ADDRESS-TYPE   PORTS
webapp-abcde   IPv4           80
webapp-fghij   IPv4           80
webapp-klmno   IPv4           80

D No resources found in default namespace.

💡 Hint

EndpointSlices group pod IPs but do not duplicate the same slice multiple times.

Each EndpointSlice object represents a subset of pods for the service. With 3 pods, you typically see multiple EndpointSlices each listing some pods, but here the example shows separate slices for each pod IP.

❓ Configuration

advanced

Configuring EndpointSlice Controller

You want to enable EndpointSlice support in your Kubernetes cluster. Which configuration snippet correctly enables the EndpointSlice controller in the kube-controller-manager manifest?

A --feature-gates=EndpointSlices=false

B --enable-controller=endpoint-slice

C --enable-endpointslice-controller=true

D --feature-gates=EndpointSlice=true

💡 Hint

Look for the standard way Kubernetes enables features via feature gates.

Kubernetes uses feature gates to enable or disable features. The correct flag is --feature-gates=EndpointSlice=true to enable EndpointSlice support.

❓ Troubleshoot

advanced

Troubleshooting missing EndpointSlices

You notice that your service has Endpoints but no EndpointSlices. Which is the most likely cause?

A The EndpointSlice controller is disabled or not running in the cluster.

B The service type is LoadBalancer, which does not support EndpointSlices.

C The pods backing the service are not ready, so EndpointSlices are not created.

D EndpointSlices are only created for services with external IPs.

💡 Hint

Think about what component manages EndpointSlices.

EndpointSlices are created and managed by the EndpointSlice controller. If it is disabled or not running, EndpointSlices won't be created even if Endpoints exist.

🔀 Workflow

expert

Sequence to migrate from Endpoints to EndpointSlices

What is the correct order of steps to migrate a Kubernetes cluster from using Endpoints to EndpointSlices for service discovery?

A 1,2,3,4

B 2,1,3,4

C 1,3,2,4

D 3,1,2,4

💡 Hint

Think about enabling features first, then verifying, then updating services, then monitoring.

The migration starts by enabling the feature gate, then ensuring the controller runs, updating services if necessary, and finally monitoring EndpointSlices and phasing out Endpoints.