Fix Kubernetes Pending Pods: Troubleshooting Guide

In Kubernetes, when a Pod is in a Pending state, it is typically due to various reasons such as insufficient resources, network configuration issues, scheduling problems, etc. To troubleshoot a Pod in Pending state, you can follow the steps below:

1. Check the status and events of a Pod: Use the command “kubectl get pod -o wide” to view the status and events of the Pod, which can provide more detailed information about the Pod being in a Pending state.
2. Check resource constraints: Verify if the resource requests and limits of the Pod match the resource quota in the cluster by using the “kubectl describe pod” command to view the detailed information of the Pod and ensure that the resource requests and limits are properly configured.
3. Check node resources: Verify if the resources on the nodes in the cluster are sufficient to support the resource requests of the Pod. You can use the command “kubectl describe node” to view the resource usage on the nodes.
4. Check network configuration: Ensure that the network configuration is correct if the Pod needs to access external networks or other services, such as network policies, network plugins, etc.
5. Check the scheduling issue: if a Pod is not scheduled to a node, it may be due to insufficient node resources or scheduling policies. You can use the “kubectl get events” command to view the event records in the cluster and find events related to Pod scheduling.
6. Check service status: Verify if the service assigned to the Pod is running properly. If the service is not available, it may cause the Pod to be unable to start.

By following the above steps methodically, it is possible to identify the specific reason why a Pod is in a Pending state and take appropriate measures to resolve the issue.