List all empty namespaces

k-list-empty-ns.sh

#!/bin/bash

# grep -E pattern to ignore certain resources 
IGNORE="^resourcequota/gke-resource-quotas|^secret/default-toke|^serviceaccount/default"

# Get a list of all "listable" namespaced ressources
resources=$(kubectl api-resources --verbs=list --namespaced=true -o name | paste -sd, -)

namespaces=$(kubectl get namespaces -o jsonpath='{.items[*].metadata.name}')
for ns in $namespaces; do
    ns_resouces=$(kubectl get ${resources} --ignore-not-found --namespace ${ns} -o name | grep -vE "${IGNORE}")
    if [ -z "$ns_resouces" ]; then
        echo $ns
    fi
done