[k8s] add script to access router pod

k8s/bird-router.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+# Nico Schottelius, 2023-06-09
+# Enter the ceph toolbox
+
+if [ -z "$@" ];  then
+    set -- -c bird -- birdc
+fi
+set -x
+
+kubectl exec -ti $(kubectl get pods -l app.kubernetes.io/component=bird -o jsonpath='{.items[*].metadata.name}') "$@"