Custom resource management

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].status

Exercise 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}'.

Show example 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}'

Test yourself

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
- The change stays
- The operator crashes
Show answer

The operator pulls it back to the custom resource's value at the next reconciliation — The right way is to change the custom resource's spec.

Wait for the custom resource's ready condition.

kubectl wait --for=condition=____ yedek/magaza-gece -n magaza

Show answer

kubectl wait --for=condition=Ready yedek/magaza-gece -n magaza

Match.

spec

The user's request
status.conditions

Machine-readable state
observedGeneration

Processed version
kubectl wait

Wait for a condition

Next lesson: Example operator

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