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

# 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:

# ~/.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:

# 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.

# ~/.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