Label selector tester

Check which pods a selector matches, and why the others do not. Accepts kubectl --show-labels output.

Runs locally. Nothing you paste leaves this tab.

Selector

Objects and their labels

Selector syntax

app=web or app==web: label equals the value.
tier!=db: label is not db, or the label is missing.
env in (prod,staging) and env notin (dev): set-based. notin also matches objects without the label.
release / !release: the label exists / does not exist.

All requirements must match (logical AND). There is no OR: use in (a,b) for one key. Service spec.selector only supports equality, while Deployments, PDBs and NetworkPolicies accept matchExpressions.

kubectl get pods -l 'app=api,env in (prod,staging),!canary' --show-labels