Service discovery via DNS in Kubernetes - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a Kubernetes Service that uses DNS for service discovery.

Kubernetes

apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  selector:
    app: my-app
  ports:
  - protocol: TCP
    port: 80
    targetPort: [1]

Drag options to blanks, or click blank then click option'

A8080

B3000

C443

D80

Attempts:

3 left

💡 Hint

Common Mistakes

Using a port number that does not match the pod's container port.

Confusing port and targetPort.

The targetPort should match the port on the pods that the service routes to. Here, port 80 is used for simplicity.

2fill in blank

medium

Complete the command to get the DNS name of a service in the default namespace.

Kubernetes

kubectl get svc [1] -o jsonpath='{.spec.clusterIP}'

Drag options to blanks, or click blank then click option'

Adefault

Bmy-service

Ckube-dns

Dmy-pod

Attempts:

3 left

💡 Hint

Common Mistakes

Using pod names instead of service names.

Using namespace names instead of service names.

The command fetches the Cluster IP of the service named my-service, which is used for DNS-based service discovery.

3fill in blank

hard

Fix the error in the DNS query command to resolve the service name inside a pod.

Kubernetes

nslookup [1].default.svc.cluster.local

Drag options to blanks, or click blank then click option'

Akube-system

Bmy-pod

Cmy-service

Dlocalhost

Attempts:

3 left

💡 Hint

Common Mistakes

Using pod names instead of service names in DNS queries.

Using incorrect namespaces.

The DNS name for a service includes the service name, namespace, and cluster domain. Here, my-service is the correct service name to query.

4fill in blank

hard

Fill both blanks to create a headless service for DNS-based service discovery.

Kubernetes

apiVersion: v1
kind: Service
metadata:
  name: headless-service
spec:
  clusterIP: [1]
  selector:
    app: my-app
  ports:
  - port: 80
    targetPort: [2]

Drag options to blanks, or click blank then click option'

Anull

B8080

C80

D0.0.0.0

Attempts:

3 left

💡 Hint

Common Mistakes

Using a normal cluster IP instead of null for headless services.

Mismatching the target port with the container port.

Setting clusterIP to null creates a headless service, which allows direct DNS queries to pods. The targetPort should match the pod's port, here 8080.

5fill in blank

hard

Fill all three blanks to create a DNS SRV record query for a service in Kubernetes.

Kubernetes

dig +short SRV _[1]._tcp.[2].svc.[3]

Drag options to blanks, or click blank then click option'

Ahttp

Bmy-service

Ccluster.local

Ddefault

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing service name with namespace.

Using wrong cluster domain.

Omitting the underscore prefix in SRV queries.

The SRV record query format is _service._protocol.namespace.svc.cluster-domain. Here, http is the service protocol, default is the namespace, and cluster.local is the default cluster domain.