k9s

# K9s K9s is a terminal UI (TUI) for Kubernetes. It is faster than clicking in a web dashboard and morediscoverable than raw `kubectl`. ## When to Use - **Terminal-Based Kubernetes Cluster Management**: Fast, interactive curses UI for navigating pods, services, and deployments. - **Real-Time Log Streaming & Resource Monitoring**: Tailing multi-pod logs, sorting by CPU/memory, and port forwarding. - **Custom K9s Plugins & Aliases**: Extending the CLI with custom shell commands (e.g. running stern, cert-manager status). - **Read-Only Inspection & Troubleshooting**: Safely debugging production clusters with read-only modes. ## Quick Start ```bash # Launch k9s with active kubeconfig k9s # Navigation shortcuts in k9s: # :pods - View all pods across namespaces # :deploy - View deployments # :svc - View services # /<term> - Filter items in active view # l - Stream logs for selected pod # s - Open shell (exec) inside selected container ``` ## Core Concepts ### Custom Plugins Configuration (plugins.yaml) Adding custom keyboard commands for rapid debugging: ```yaml # ~/.config/k9s/plugins.yaml plugin: # Press 'Shift-D' on a deployment to view detailed rollout history rollout-history: shortCut: Shift-D confirm: false description: "Rollout History" scopes: - deployments command: kubectl background: false args: - rollout - history - deployment/$NAME - -n - $NAMESPACE # Press 'Shift-F' on a pod to launch interactive debug container debug-pod: shortCut: Shift-F confirm: true description: "Debug Pod" scopes: - pods command: kubectl background: false args: - debug - -it - $NAME - --image=nicolaka/netshoot - -n - $NAMESPACE ``` ### Essential Navigation & Keyboard Shortcuts Accelerating cluster management: - `:pod`: Jump to Pod view across namespaces. - `:svc`, `:deploy`, `:ing`: Jump to Services, Deployments, and Ingresses. - `/`: Search and filter resources by name or status. - `l`: Tail logs for selected pod or container. - `s`: Open an interactive shell (`sh` / `bash`) inside the selected container. - `Shift-F`: Port-forward local port to selected pod service port. - `y`: View full YAML manifest of selected resource. ### Launching K9s with Custom Options Starting K9s in secure modes: ```bash # Launch in read-only mode to prevent accidental pod deletion in production k9s --readonly --namespace production # Specify custom context and refresh rate k9s --context prod-eks-cluster --refresh 2 ``` ## Common Patterns ### Custom K9s Shortcuts and Plugins **Problem**: Frequently running custom kubectl commands across different namespaces. **Solution**: Define custom plugins in `~/.config/k9s/plugin.yaml`. ```yaml # ~/.config/k9s/plugin.yaml plugin: raw-logs: shortCut: Shift-L description: "Tail logs without truncation" scopes: - pods command: kubectl background: false args: - logs - -f - $NAME - -n - $NAMESPACE - --context - $CONTEXT ``` ## Best Practices **Do**: - Use `k9s --readonly` when connecting to production environments to prevent accidental deletions. - Configure custom plugins in `~/.config/k9s/plugins.yaml` for repetitive `kubectl` commands. - Use the port-forward shortcut (`Shift-F`) instead of typing long `kubectl port-forward` commands. - Filter views using `<all>` namespaces or specific namespaces to reduce API server query loads. **Don't**: - Leave dozens of active port forwards open; manage and terminate them in the `:portforwards` view. - Run K9s against large enterprise clusters without setting appropriate `--refresh` intervals. - Delete persistent volume claims (PVCs) through K9s without verifying backups. ## Troubleshooting | Error | Cause | Solution | | :--------------------------------------- | :----------------------------------------------------------------- | :---------------------------------------------------------------------------------------------- | | `Boom!! K9s cannot connect to cluster` | Active kubeconfig context invalid or cluster endpoint unreachable. | Verify connection: `kubectl cluster-info` and switch context with `kubectl config use-context`. | | `Pod logs failing to stream in k9s` | Pod container crashed or user lacks RBAC `pods/log` permission. | Check container status and verify cluster role permissions. | | `Terminal display corrupted / artifacts` | Incompatible terminal terminfo or small terminal window. | Run `export TERM=xterm-256color` and maximize terminal window. | ## References - [K9s Documentation](https://k9scli.io/)