Test DNS resolution from inside the cluster

Kubernetes Administration Essentials · 4:56

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Lyrics

[Verse 1]
When your pods can't find each other in the night
And services seem hidden from their sight
There's a way to check if DNS is working right
From inside your cluster, bring the truth to light

Run a test pod with busybox in hand
One-three-six version, stable and so grand
Interactive terminal, then remove on command
DNS resolution, help us understand

[Chorus]
kubectl run dns-test, busybox one-three-six
Interactive, remove it, temporary fix
nslookup service-name, see if it resolves
Inside the cluster, mystery it solves

Test your DNS, test your DNS
From within the cluster, no need to guess
Test your DNS, test your DNS
Resolution working, cleaning up the mess

[Verse 2]
Sometimes short names fail but don't despair
Fully qualified domains show what's really there
Service dot namespace dot svc dot cluster dot local care
Complete the puzzle, DNS everywhere

Busybox container, lightweight and clean
Interactive flag lets you see the screen
Remove when finished, keeping cluster lean
Restart policy never, ephemeral machine

[Chorus]
kubectl run dns-test, busybox one-three-six
Interactive, remove it, temporary fix
nslookup service-name, see if it resolves
Inside the cluster, mystery it solves

Test your DNS, test your DNS
From within the cluster, no need to guess
Test your DNS, test your DNS
Resolution working, cleaning up the mess

[Bridge]
When debugging network issues late at night
This little test pod makes everything bright
From inside looking out, the perspective's right
DNS resolution brought into the light

[Chorus]
kubectl run dns-test, busybox one-three-six
Interactive, remove it, temporary fix
nslookup service-name, see if it resolves
Inside the cluster, mystery it solves

Test your DNS, test your DNS
From within the cluster, no need to guess
Test your DNS, test your DNS
Resolution working, cleaning up the mess

[Outro]
Now you know the secret, debugging made clear
Test from within when services disappear
DNS resolution, keep your cluster near
Busybox nslookup, the answer's here

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