Custom resource management
- Docker & Kubernetes course
- Expert
- Lesson 16/47
- 4 min
Learn how an Operator manages custom resources.
Managing custom resources
An operator turns the custom resource the user writes into child objects and reports the result in status. The user only interacts with the custom resource; they shouldn't touch the child objects by hand, because the operator reverts them in the next reconciliation:
$ kubectl get yedek magaza-gece -n magaza -o yaml | tail -8
status:
conditions:
- type: Ready
status: "True"
reason: CronJobOlusturuldu
observedGeneration: 3
sonYedek: "2026-11-03T03:00:12Z"Conditions
The conditions list in the status gives the state in a machine-readable form. kubectl wait can wait on these conditions; that way CI pipelines wait for the custom resource to be ready:
kubectl wait --for=condition=Ready yedek/magaza-gece -n magaza --timeout=120s
yedek.ornek.com/magaza-gece condition met
kubectl get yd -A -o custom-columns=AD:.metadata.name,HAZIR:.status.conditions[0].statusPractice Update the custom resource and wait
Write three commands: apply the patch {"spec":{"saklamaGun":30}} to the magaza-gece Yedek in magaza with --type=merge; wait for the Ready condition with a 120-second timeout; print the Yedek's observedGeneration with jsonpath='{.status.observedGeneration}'.
Starter code
# buraya yazSample solution
kubectl patch yedek magaza-gece -n magaza --type=merge -p '{"spec":{"saklamaGun":30}}'
kubectl wait --for=condition=Ready yedek/magaza-gece -n magaza --timeout=120s
kubectl get yedek magaza-gece -n magaza -o jsonpath='{.status.observedGeneration}'Expected output
yedek.ornek.com/magaza-gece patched yedek.ornek.com/magaza-gece condition met 4
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What happens if you change the schedule of the CronJob the operator created by hand?
- The custom resource is updated
- The operator pulls it back to the custom resource's value at the next reconciliation Correct answer
- The change stays
- The operator crashes
Explanation: The right way is to change the custom resource's spec.
2 Wait for the custom resource's ready condition.
kubectl wait --for=condition=____ yedek/magaza-gece -n magazakubectl wait --for=condition=Ready yedek/magaza-gece -n magazaExplanation: Ready is a common condition type.
3 Match.
| Term | Meaning |
|---|---|
spec |
The user's request |
status.conditions |
Machine-readable state |
observedGeneration |
Processed version |
kubectl wait |
Wait for a condition |