Troubleshooting

Debugging a Kubernetes Application

1. Check Pod Logs:

   • Use kubectl logs <pod-name> to view the logs of a specific pod.

   • Example:

     kubectl logs my-app-pod

2. Describe the Pod:

   • Use kubectl describe pod <pod-name> to get detailed information about the pod.

   • Example:

     kubectl describe pod my-app-pod

3. Check Pod Events:

   • Events can provide insights into issues like scheduling problems or container crashes.

   • Example:

     kubectl get events --sort-by='.metadata.creationTimestamp'

4. Exec into the Pod:

   • Use kubectl exec -it <pod-name> -- /bin/sh to get a shell inside the pod for further investigation.

   • Example:

     kubectl exec -it my-app-pod -- /bin/sh

Debugging a GitLab CI Script

1. Validate .gitlab-ci.yml:

   • Use the CI Lint tool in GitLab to validate your .gitlab-ci.yml file.

   • Example:

     # In GitLab UI, go to CI/CD > Pipelines > CI Lint

2. Check Pipeline Logs:

   • Review the logs of each job in the pipeline to identify errors.

   • Example:

     # In GitLab UI, go to CI/CD > Pipelines > Jobs > [Job Name]

3. Use Debug Tracing:

   • Enable debug tracing by setting the CI_DEBUG_TRACE variable to true.

   • Example:

     variables:
       CI_DEBUG_TRACE: "true"

4. Run Jobs Locally:

• Use the GitLab Runner to run jobs locally for debugging.

• Example:

  gitlab-runner exec docker <job-name>

Debugging an ArgoCD Application

To debug an ArgoCD application using the UI, follow these steps:

1. Select the Application:

   • Once logged in, you will see a list of applications. Click on the application you want to debug.

2. Check Application Status:

   • The application details page will show the current status of the application, including whether it is Synced or OutOfSync, and any health status like Healthy or Degraded.

3. Sync the Application:

   • If the application is out of sync, you can manually sync it by clicking the Sync button. This will synchronize the application's state with the desired state defined in the Git repository.
   Tip

   Sometimes, giving the Application an Hard Refresh might be useful. The button can be found by clicking the little arrow pointing downwards next to the Refresh button.

4. View Application Logs:

   • To view logs, navigate to the Pods section under the Resources tab. Click on the specific pod you are interested in, and then click on the Logs tab to see the logs for that pod.

5. Check Events and Conditions:

   • Under the Events tab, you can see events related to the application. This can help identify issues such as failed deployments or resource constraints.

6. Check Events and Conditions in the cluster:

   • Use kubectl get events and kubectl describe <resource> to check for events and conditions affecting the application.

   • Example:

     kubectl get events
     kubectl describe application my-app-deployment