Pods Restarting After ConfigMap or Secret Change in Kubernetes

Why this matters

ConfigMap or Secret changes are a common source of drift between expectations and reality. If pods restart after a config change, you can end up with partial rollouts, inconsistent behavior, or downtime if the new config is invalid.

Symptoms

• Shortly after applying a ConfigMap or Secret change, pods for a workload start restarting.
• kubectl get pods shows increasing restart counts for the same pods.
• Logs show new errors about missing keys, invalid values, or auth failures.
• Users report errors immediately after a configuration deployment.

Common root causes

• ConfigMap keys renamed or removed but the application still expects them.
• Secrets rotated but pods are still using old value assumptions.
• Config syntax errors (YAML/JSON) that the application fails to parse on startup.
• Mismatch between mounted path and what the application expects.
• Sidecars referencing the same config but not updated properly.

How KubeGraf helps

• Incident timeline shows exactly when ConfigMaps/Secrets changed relative to pod restarts.
• Pod details view surfaces restart counts, reasons, and timestamps.
• Easy navigation from a pod to its referenced ConfigMaps and Secrets.
• Helps you visualize which workloads share a given ConfigMap/Secret.

Step-by-step using KubeGraf UI

1. Confirm restarts and time window

• In a terminal, run kubectl get pods -n <namespace> and note which pods have rising restart counts.
• Open KubeGraf, select cluster and namespace.
• In the Pods view, sort by restart count or filter to pods with > 0 restarts.

2. Check recent Events and restart reasons

• For a restarting pod, open Events and Status.
• Note the Last State and any probe failures or container exit reasons.

3. Correlate with ConfigMap/Secret changes

• Open the Incident Timeline for the workload or namespace.
• Look for entries such as ConfigMap <name> updated or Secret <name> updated.
• Compare the time these changes were applied with the first observed restarts.

4. Inspect current config content

• From the pod details, follow links to referenced ConfigMaps/Secrets.
• Verify keys expected by the application are present and correctly named.
• Check for obvious typos, missing values, or wrong formats.
• Confirm mounted paths (if using volume mounts) match the app's configuration.

5. Decide rollback vs fix

• If the new config is clearly wrong and breaking prod, roll back to the last known-good version via your config repo / GitOps.
• Watch pods in KubeGraf to confirm restarts stop.
• If you can fix forward quickly, correct the ConfigMap/Secret and apply via CI/GitOps, then watch restart counts again.

6. Verify behavior after change

• Confirm pods stop restarting and remain in Running.
• Validate key paths in the application that depend on the changed config.
• Check downstream dependencies (DB, queues) for normal behavior.

What to check next

• Do other workloads reference the same ConfigMap/Secret and show similar restarts?
• Did the change also modify probes, ports, or URLs indirectly?
• Are you rotating Secrets in a way that's compatible with all workloads using them?

Common mistakes

• Editing ConfigMaps/Secrets directly in the cluster and forgetting to update Git (drift).
• Assuming an application reloads config dynamically when it actually requires a restart.
• Changing config format without updating validation in the application.
• Overlooking sidecars or jobs that also depend on the same Secret.

Related issues

• CrashLoopBackOff Kubernetes debugging
• Deployment rollout stuck / ProgressDeadlineExceeded
• "It was working yesterday" incidents

Expected outcome

After following this playbook you should:

• Clearly attribute pod restarts to a specific ConfigMap or Secret change.
• Either roll back to a known-good config or apply a corrected version.
• See pods stabilize, restart counts stop increasing, and behavior match expectations.

[ TODO: screenshot showing KubeGraf Incident Timeline with a ConfigMap change followed by pod restarts. ]