Check kubernetes api server from inside a pod

health.sh

#!/usr/bin/env bash

/usr/bin/curl -sf -H "Authorization: Bearer $(</var/run/secrets/kubernetes.io/serviceaccount/token)" \
              --cacert "/var/run/secrets/kubernetes.io/serviceaccount/ca.crt" \
              "https://${KUBERNETES_PORT_443_TCP_ADDR}/version"
# OR

/usr/bin/nc -w3 -z ${KUBERNETES_SERVICE_HOST} ${KUBERNETES_SERVICE_PORT}