How to get the pods from the namespaces with a particular label?

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It is possible to get all the pods on the cluster:

kubectl get pod --all-namespaces -o wide

It is also possible to get all pods on the cluster with a specific label:

kubectl get pod --all-namespaces -o wide --selector some.specific.pod.label

It is even possible to get all pods on the specific node of the cluster:

kubectl get pods --all-namespaces -o wide --field-selector spec.nodeName=<node>

The question is, how to get all pods from the namespaces with a particular label?

e.g. kubectl get pod --namespace-label some.specific.namespace.label -o wide (pseudocode)

kubectl kubernetes-pod kubernetes
1 Answers

One cannot do that operation in one shot, because labels on Namespace objects are not propagated down upon their child objects. Since kubectl is merely doing a GET on /api/v1/whatevers there is no obvious way to make a REST request to two endpoints at once and join them together.

You'll want either a for loop in shell, or to use one of the many API client bindings to create a program that does the Namespace fetch, then a Pod fetch for those matching Namespaces; for example:

for n in $(kubectl get ns --selector some.specific.namespace.label -o name); do
    # it's possible kubectl -n will accept the "namespace/foo" output of -o name
    # or one can even -o go-template='{{ range .items }}{{ .metadata.name }} {{ end }}'
    n=${n##namespace/}
    kubectl -n "$n" get pods -o wide
done
user_2250160
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