Error #21 - NamespaceTerminating

IN TODAY'S EDIT

USE CASE

Namespace Terminating error : Troubleshoot and Fix

The NamespaceTerminating error in Kubernetes occurs when a namespace is stuck in the Terminating state and is not getting deleted properly. This usually happens when Kubernetes resources within the namespace are preventing it from being fully removed.

🚨 Causes of NamespaceTerminating Error:

1. Finalizers Blocking Deletion

   • Some resources in the namespace have finalizers, which are meant to run cleanup operations before deletion. If the finalizer process fails or hangs, the namespace remains in the Terminating state.

2. Stuck API Resources

   • Certain API objects (like CRDs, PVs, or Webhooks) might be stuck in a pending or terminating state, preventing the namespace from getting deleted.

3. Persistent Volumes Not Releasing

   • If PersistentVolumes (PVs) associated with the namespace are not properly unmounted or released, the namespace deletion gets delayed.

4. Network or API Server Issues

   • If there is a problem with the Kubernetes API server, it might not process the namespace deletion request properly.

5. Controller or Operator Malfunction

   • A custom controller or operator might be holding resources within the namespace, preventing termination.

🔍 Troubleshooting Steps:

1️⃣ Check the Namespace Status

kubectl get namespace <namespace-name> -o json | jq '.status'

Look for the "status":"Terminating" field.

2️⃣ Identify Finalizers Blocking Deletion

kubectl get namespace <namespace-name> -o jsonpath='{.spec.finalizers}'

If there are finalizers, they need to be removed manually.

3️⃣ Manually Remove Finalizers

Run the following command to edit the namespace and remove the finalizers:

kubectl edit namespace <namespace-name>

• Find the finalizers section and delete all entries.

• Save and exit the editor.

Alternatively, use this command to remove finalizers forcefully:

4️⃣ Check for Stuck Resources

List all resources in the namespace:

kubectl api-resources --verbs=list --namespaced -o name | xargs -n 1 kubectl get --show-kind --ignore-not-found -n <namespace-name>

If any resources are stuck, delete them manually:

5️⃣ Verify CustomResourceDefinitions (CRDs)

Check if CRDs are preventing deletion:

kubectl get crds | grep <namespace-name>

If needed, delete CRDs manually:

kubectl delete crd <crd-name>

6️⃣ Check for Webhook Issues

List all webhooks and check if they refer to the namespace:

kubectl get mutatingwebhookconfigurations,validatingwebhookconfigurations -o yaml

If necessary, remove webhook configurations.

🛡️ Preventive Measures:

✅ Use Finalizers Properly

• Only use finalizers when absolutely necessary. Ensure they clean up resources correctly before allowing namespace deletion.

✅ Automate Cleanup Processes

• Implement automated scripts to remove stuck resources before deleting namespaces.

✅ Monitor Persistent Volumes

• Ensure PVs are properly unmounted before deleting associated namespaces.

✅ Ensure Webhooks and CRDs Are Well-Managed

• Regularly audit webhook configurations and CRDs to avoid namespace deletion issues.

✅ Improve API Server Availability

• Ensure the API server is healthy to process deletion requests efficiently.