Master Advanced kubectl Tricks for Faster Kubernetes Debugging

1 Print the current API version

# kubectl primarily interacts with the ApiServer; the following command prints detailed API information, useful for debugging custom APIs.
$ kubectl get ns -v=9

2 Filter pods by status and delete them

This snippet shows how to locate pods in a specific phase (e.g., Pending) across all namespaces, generate delete commands with jq, and execute them via xargs. Variants can target other phases such as Failed or specific deployments.

$ kubectl get pods --all-namespaces --field-selector status.phase=Pending -o json \
  | jq '.items[] | "kubectl delete pods \(.metadata.name) -n \(.metadata.namespace)"' \
  | xargs -n 1 bash -c

# Example for running pods
$ kubectl get pods --all-namespaces --field-selector status.phase=Running -o json \
  | jq '.items[] | "kubectl get pods \(.metadata.name) -o wide -n \(.metadata.namespace)"'

3 List all pods running on a specific node

Using a field selector you can directly query pods scheduled on a given node.

$ kubectl get pods --all-namespaces -o wide --field-selector spec.nodeName=pve-node1

4 Count pod distribution across nodes

An awk pipeline extracts the node name column and aggregates occurrences, providing a quick view of how many pods run on each machine.

$ kubectl -n default get pods -o wide -l app="nginx" \
  | awk '{print $7}' \
  | awk '{ count[$0]++ }
    END {
      printf("%-35s: %s
","Node","Count");
      for (n in count) printf("%-35s: %d
", n, count[n]);
    }'

# Sample output
Node                               : Count
pve-node1                          : 1
pve-node2                          : 1

5 Using kubectl proxy

The proxy creates a local HTTP proxy to the Kubernetes API server, allowing direct API calls without additional authentication. After starting the proxy, you can issue curl requests against localhost:8080 and increase verbosity for debugging.

# Start the proxy on port 8080
$ KUBECONFIG=~/.kube/config-symv3 kubectl proxy -p 8080

# Verify the API server is reachable
$ curl -k -v -X GET -H "Accept: application/json,*/*" \
    -H "User-Agent: kubectl/v1.21.3 (linux/amd64) kubernetes/ca643a4" \
    'http://localhost:8080/api?timeout=32s'

The default proxy blocks certain APIs (e.g., /api/.../pods/.../exec ) and only allows local host access. You can relax these restrictions with options such as: <code># Allow any host --accept-hosts='^localhost$,^127\.0\.0\.1$,^\[::1\]$' # Remove path restrictions to enable exec/attach --reject-paths='' $ kubectl proxy -p 8080 --keepalive 3600s --reject-paths='' -v=9 </code>

Even if the proxy seems unnecessary for simple tasks, it becomes valuable when you need to inspect raw API requests, for example while debugging the Kubernetes Dashboard.

6 Summary

kubectl is a versatile CLI tool; the commands above illustrate several advanced usages that can simplify debugging and routine operations without diving into the client‑API library.