DNS in Kubernetes (CoreDNS) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check the CoreDNS pods in the kube-system namespace.

Kubernetes

kubectl get pods -n [1] -l k8s-app=kube-dns

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

Adns

Bdefault

Ccore-dns

Dkube-system

Attempts:

3 left

💡 Hint

Common Mistakes

Using the default namespace instead of kube-system

Using an incorrect label selector

The CoreDNS pods run in the kube-system namespace, so you must specify it to list them.

2fill in blank

medium

Complete the command to view the CoreDNS ConfigMap in the kube-system namespace.

Kubernetes

kubectl get configmap [1] -n kube-system -o yaml

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

Acoredns-config

Bcoredns

Cdns-config

Dcore-dns-configmap

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect ConfigMap names like coredns-config

Forgetting the namespace flag

The CoreDNS ConfigMap is named coredns in the kube-system namespace.

3fill in blank

hard

Fix the error in the CoreDNS ConfigMap snippet to correctly forward DNS queries to 8.8.8.8.

Kubernetes

forward . [1]

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

A8.8.8.8:5353

B8.8.8.8

C8.8.8.8:53

D8.8.4.4

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the port number

Using wrong port like 5353

Using wrong IP address

The forward plugin requires the IP and port, so 8.8.8.8:53 is correct.

4fill in blank

hard

Fill both blanks to create a CoreDNS stub domain forwarding example for example.com to 10.0.0.1.

Kubernetes

example.com:53 {
    [1] . [2]
}

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

Aforward

Bproxy

C10.0.0.1

D8.8.8.8

Attempts:

3 left

💡 Hint

Common Mistakes

Using the deprecated proxy plugin

Using wrong IP address

Swapping plugin and IP positions

The forward plugin is used to forward queries for example.com to the IP 10.0.0.1.

5fill in blank

hard

Fill all three blanks to create a CoreDNS hosts plugin block mapping example.com to 10.0.0.2 with TTL 30.

Kubernetes

hosts {
    [1] [2] [3]
    fallthrough
}

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

A10.0.0.2

Bexample.com

C30

Dexample.net

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping domain and IP positions

Using wrong TTL value

Using wrong domain name

The hosts plugin maps example.com to 10.0.0.2 with a TTL of 30 seconds.