k9s: Terminal UI and Read-Only Mode

k9s is an interactive terminal UI for Kubernetes; --readonly disables all mutating actions, which is the only sane way to run it near CI.

k9s shines for humans debugging a cluster. It is not a scripting tool: it needs a TTY and is interactive, so in CI contexts it is used read-only by an operator, not by the pipeline itself.

What it does

k9s renders cluster resources in a live, navigable TUI: switch resources with :pods, drill into logs, exec into containers, and watch events. --readonly removes destructive key actions (delete, edit, scale) so a session cannot mutate the cluster.

Common usage

Terminal

k9s --readonly                 # safe view-only session
k9s -n payments                # start scoped to a namespace
k9s --context staging          # pick a context
k9s --command pods             # open directly on the pods view

Options

Flag	What it does
--readonly	Disable all mutating actions
-n, --namespace	Start scoped to a namespace
--context	Use a specific kubeconfig context
--command	Open directly on a given view
--headless	Hide the header for more rows

In CI

k9s is interactive and needs a TTY, so it does not belong inside an automated pipeline step. Treat it as a read-only operator tool: when a CI run fails, an engineer opens k9s --readonly against the same cluster to investigate, while the pipeline relies on stern and kubectl for non-interactive output. You can also enforce read-only via the config so no session can mutate.

Common errors in CI

Launching k9s without a TTY (e.g. in a non-interactive runner step) fails with open /dev/tty: no such device or address or a blank hang; do not run it unattended. Boom!! No connectivity means the kubeconfig context is unreachable or its token expired. Unable to locate K8s cluster configuration means KUBECONFIG is unset.