Allow specifying cluster signing ca/key

hack/local-up-cluster.sh

@@ -213,6 +213,8 @@ ENABLE_CONTROLLER_ATTACH_DETACH=${ENABLE_CONTROLLER_ATTACH_DETACH:-"true"} # cur
 CERT_DIR=${CERT_DIR:-"/var/run/kubernetes"}
 ROOT_CA_FILE=${CERT_DIR}/server-ca.crt
 ROOT_CA_KEY=${CERT_DIR}/server-ca.key
+CLUSTER_SIGNING_CERT_FILE=${CLUSTER_SIGNING_CERT_FILE:-"${ROOT_CA_FILE}"}
+CLUSTER_SIGNING_KEY_FILE=${CLUSTER_SIGNING_KEY_FILE:-"${ROOT_CA_KEY}"}
 
 # name of the cgroup driver, i.e. cgroupfs or systemd
 if [[ ${CONTAINER_RUNTIME} == "docker" ]]; then
@@ -545,8 +547,8 @@ function start_controller_manager {
       --v=${LOG_LEVEL} \
       --service-account-private-key-file="${SERVICE_ACCOUNT_KEY}" \
       --root-ca-file="${ROOT_CA_FILE}" \
-      --cluster-signing-cert-file="${ROOT_CA_FILE}" \
-      --cluster-signing-key-file="${ROOT_CA_KEY}" \
+      --cluster-signing-cert-file="${CLUSTER_SIGNING_CERT_FILE}" \
+      --cluster-signing-key-file="${CLUSTER_SIGNING_KEY_FILE}" \
       --enable-hostpath-provisioner="${ENABLE_HOSTPATH_PROVISIONER}" \
       ${node_cidr_args} \
       --pvclaimbinder-sync-period="${CLAIM_BINDER_SYNC_PERIOD}" \