Switch between Kubernetes namespaces

kns

kns() {
	local CTX=$(kubectl config current-context)
	local NAMESPACE=${1}
	if [[ -z $NAMESPACE ]]; then
		local OPTIONS=$(kubectl get namespaces -o jsonpath='{range .items[*].metadata.name}{@}{"\n"}{end}')
		OPTIONS+=' EXIT'

		local NS=$(kubectl config view -o jsonpath="{.contexts[?(@.name=='$CTX')].context.namespace}")
		if [[ -z $NS ]]; then
			NS="default"
		fi

		echo "Current ctx/ns: $CTX/$NS"
		echo "Switch to which namespace? (or EXIT)"

		select opt in $OPTIONS; do
			if [ "$opt" = "EXIT" ]; then
				echo "Staying in the current namespace"
			else
				kubectl config set-context "$CTX" --namespace "$opt"
			fi
			break
		done
	else
		kubectl config set-context "$CTX" --namespace "$NAMESPACE"
	fi
	NS=$(kubectl config view -o jsonpath="{.contexts[?(@.name=='$CTX')].context.namespace}")
	if [[ -z $NS ]]; then
		NS="default"
	fi
	echo "Current ctx/ns: $CTX/$NS"
}