01
Read the container’s waiting message
Inspect the affected container’s waiting state and Pod events. Distinguish a configuration error from a process that started and exited. If the container has never run, repeatedly requesting its application logs will not explain the missing configuration.
Our test Pod referenced a Secret key named required, while the Secret contained only available. The waiting reason was CreateContainerConfigError and its message named the missing key. No container ID had been assigned for a running application.
kubectl -n your-namespace describe pod your-pod
kubectl -n your-namespace get pod your-pod -o yaml02
Compare the reference without exposing the secret
Check the Secret name and key from the live Pod specification. Inspect the Secret’s metadata and available key names through a suitable authorized interface. kubectl describe secret normally shows key names and byte counts rather than decoded values.
Do not paste a complete Secret object or environment dump into an issue to investigate a spelling mistake. A key name and the waiting message are usually sufficient for this part of the diagnosis. Read permissions for Secret contents should remain appropriately limited.
kubectl -n your-namespace describe secret app-credentials
# The container reference should name the intended Secret and key:
# secretKeyRef.name: app-credentials
# secretKeyRef.key: token03
Repair the intended contract
If the workload reference is wrong, correct it in the owning controller’s template. If the reference is right but the key was not provisioned, supply that intended key through the organization’s secret management process. Confirm the namespace on both sides.
Our disposable test supplied the missing required key to the same Secret. The kubelet retried, and the Pod became Ready without a manual deletion. This isolated a missing-key prerequisite; it did not require relaxing the reference to optional.
# Container fragment only; provision the real value through your secret workflow.
env:
- name: APP_TOKEN
valueFrom:
secretKeyRef:
name: app-credentials
key: token04
Verify presence without logging the value
Confirm that the waiting error clears and the intended container starts. For a Python diagnostic container with the example APP_TOKEN variable, the check below reports only whether the value is nonempty. Use an application-appropriate equivalent elsewhere.
The lab’s post-repair check returned present and never printed the token. That proves availability to the process, not acceptance by a remote service. Credential validity and application authorization require their own appropriately scoped functional check.
kubectl -n your-namespace exec your-pod -c app -- \
python -c 'import os; assert bool(os.environ.get("APP_TOKEN")); print("present")'05
Remember when the environment was created
This example repaired a prerequisite before the first container start. Updating a Secret-backed environment variable in an already running container is different: the process does not automatically receive the changed value. Plan a suitable rollout when rotating that configuration.
Keep the corrected reference, the cleared waiting message, and a non-sensitive application verification in the change record. If the next failure is an authentication rejection from a dependency, continue there rather than assuming the original configuration error remains.
Know the limits
Tested on Kubernetes v1.32.2 using a disposable Secret with a deliberately missing key. No real credentials were used. The example concerns a required secretKeyRef environment variable; optional references and mounted-volume errors can behave differently.
Sources & further reading
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