Unlock Hidden kubectl Tricks: Boost Your Kubernetes Workflow

kubectl is the official command‑line tool for Kubernetes, enabling convenient interaction with a cluster. The following tips assume readers already have basic Kubernetes experience.

1. Print the current API calls

# kubectl primarily talks to the API server; this command helps debug API interactions.
$ kubectl get ns -v=9

2. Filter pods by status and delete them

Use jq together with kubectl to generate delete commands for pods in a specific phase (e.g., Pending) across all namespaces.

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)"'

# Delete Completed pods in a single namespace
kubectl -n default get pods | grep Completed | awk '{print $1}' | xargs kubectl -n default delete pods

3. List all pods on a specific node

kubectl supports label and field selectors; the following command shows pods scheduled on pve-node1:

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

4. Count pod distribution across nodes

Combine awk with kubectl to tally how many pods of a given app run on each node.

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

# Sample output
Word                               : Count
NODE                               : 1
pve-node1                          : 1
pve-node2                          : 1

5. Using kubectl proxy

The proxy acts as a lightweight API server gateway, allowing direct API calls without authentication. Starting a proxy on port 8080 lets you inspect traffic with high verbosity.

# Start proxy
KUBECONFIG=~/.kube/config-symv3 kubectl proxy -p 8080
kubectl get ns
NAME    STATUS   AGE
default Active   127d

# Proxy options (default restricts exec/attach)
--accept-hosts='^localhost$,^127\.0\.0\.1$,^\[::1\]$'
--reject-paths='^/api/.*/pods/.*/exec,^/api/.*/pods/.*/attach'
# To allow exec, clear reject‑paths
kubectl proxy -p 8080 --keepalive 3600s --reject-paths='' -v=9

While some may think kubectl proxy is unnecessary, it becomes valuable when debugging components like the Kubernetes dashboard, as it logs full request details.

Summary

kubectl is a powerful CLI; the commands above illustrate a few advanced uses. You don’t need to memorize them all, but knowing they exist can save time when tackling ad‑hoc tasks without diving into the client API.