'Specifying Which Kubernetes Namespaces to Display Resources from with the CLI Only
Is it possible to display Kubernetes (K8s) resources from multiple specified namespaces with only the CLI (kubectl)?
In other words, given two namespaces in a K8s cluster:
kubectl get namespaces \
--output=go-template \
--template='{{ range .items }}{{ .metadata.name }}{{ "\n" }}{{ end }}'
#=>
. . .
$SOME_NAMESPACE
. . .
$ANOTHER_NAMESPACE
. . .
would it be possible to get resources (such as pods) from only those two namespaces ($SOME_NAMESPACE and $ANOTHER_NAMESPACE) using only kubectl?
Supplying the --all-namespaces flag and filtering using either the --field-selector or --selector flags will not work, because both flags accept only =, == and != operators.
Solution 1:[1]
According to the discussion that has already occurred in this GitHub issue, it does not currently seem possible to specify multiple namespaces: either with just the --namespace flag alone or using a filtering flag such as --selector.
You can, for now, use workarounds such as Bash brace expansion, as suggested here, or feeding the output of the get command with the --all-namespaces flag into awk:
kubectl get pods \
--all-namespaces \
| awk \
-v SOME_NAMESPACE=$SOME_NAMESPACE \
-v ANOTHER_NAMESPACE=$ANOTHER_NAMESPACE \
'$1 == SOME_NAMESPACE || $1 == ANOTHER_NAMESPACE'
Solution 2:[2]
You may use go-template to print the name of the pods belonging to the two namespaces, following is an example of printing pods from the test-1 and test-2 namespace.
kubectl get pod -A -o go-template='{{range .items}}{{if or (eq .metadata.namespace "test-1") (eq .metadata.namespace "test-2") }}{{printf "%s %s\n" .metadata.namespace .metadata.name}}{{end}}{{end}}'
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | Mike |
| Solution 2 | P.... |