Add nokubeproxy option in START_MODE

Some CNIs such as OVN don't use kubeproxy and provide
there own implementation for network proxy .
This patch allow to disable the kubeproxy start in the
local-up-cluster.sh script.

It is also move the generation of the certificate and
kubeconfig to  start_kubeproxy function so it will be
generated only when it needed.

This is useful for us for developement and CI testing.
Signed-off-by: Moshe Levi <moshele@mellanox.com>

hack/local-up-cluster.sh

@@ -109,7 +109,7 @@ ENABLE_ADMISSION_PLUGINS=${ENABLE_ADMISSION_PLUGINS:-"NamespaceLifecycle,LimitRa
 DISABLE_ADMISSION_PLUGINS=${DISABLE_ADMISSION_PLUGINS:-""}
 ADMISSION_CONTROL_CONFIG_FILE=${ADMISSION_CONTROL_CONFIG_FILE:-""}
 
-# START_MODE can be 'all', 'kubeletonly', or 'nokubelet'
+# START_MODE can be 'all', 'kubeletonly', 'nokubelet', or 'nokubeproxy'
 START_MODE=${START_MODE:-"all"}
 
 # A list of controllers to enable
@@ -457,7 +457,6 @@ function generate_certs {
     kube::util::create_serving_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" "server-ca" kube-apiserver kubernetes.default kubernetes.default.svc "localhost" ${API_HOST_IP} ${API_HOST} ${FIRST_SERVICE_CLUSTER_IP}
 
     # Create client certs signed with client-ca, given id, given CN and a number of groups
-    kube::util::create_client_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" 'client-ca' kube-proxy system:kube-proxy system:nodes
     kube::util::create_client_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" 'client-ca' controller system:kube-controller-manager
     kube::util::create_client_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" 'client-ca' scheduler  system:kube-scheduler
     kube::util::create_client_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" 'client-ca' admin system:admin system:masters
@@ -466,11 +465,17 @@ function generate_certs {
     # Create matching certificates for kube-aggregator
     kube::util::create_serving_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" "server-ca" kube-aggregator api.kube-public.svc "localhost" ${API_HOST_IP}
     kube::util::create_client_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" request-header-ca auth-proxy system:auth-proxy
+
     # TODO remove masters and add rolebinding
     kube::util::create_client_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" 'client-ca' kube-aggregator system:kube-aggregator system:masters
     kube::util::write_client_kubeconfig "${CONTROLPLANE_SUDO}" "${CERT_DIR}" "${ROOT_CA_FILE}" "${API_HOST}" "${API_SECURE_PORT}" kube-aggregator
 }
 
+function generate_kubeproxy_certs {
+    kube::util::create_client_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" 'client-ca' kube-proxy system:kube-proxy system:nodes
+    kube::util::write_client_kubeconfig "${CONTROLPLANE_SUDO}" "${CERT_DIR}" "${ROOT_CA_FILE}" "${API_HOST}" "${API_SECURE_PORT}" kube-proxy
+}
+
 function generate_kubelet_certs {
     kube::util::create_client_certkey "${CONTROLPLANE_SUDO}" "${CERT_DIR}" 'client-ca' kubelet system:node:${HOSTNAME_OVERRIDE} system:nodes
     kube::util::write_client_kubeconfig "${CONTROLPLANE_SUDO}" "${CERT_DIR}" "${ROOT_CA_FILE}" "${API_HOST}" "${API_SECURE_PORT}" kubelet
@@ -595,7 +600,6 @@ EOF
     # Create kubeconfigs for all components, using client certs
     kube::util::write_client_kubeconfig "${CONTROLPLANE_SUDO}" "${CERT_DIR}" "${ROOT_CA_FILE}" "${API_HOST}" "${API_SECURE_PORT}" admin
     ${CONTROLPLANE_SUDO} chown "${USER}" "${CERT_DIR}/client-admin.key" # make readable for kubectl
-    kube::util::write_client_kubeconfig "${CONTROLPLANE_SUDO}" "${CERT_DIR}" "${ROOT_CA_FILE}" "${API_HOST}" "${API_SECURE_PORT}" kube-proxy
     kube::util::write_client_kubeconfig "${CONTROLPLANE_SUDO}" "${CERT_DIR}" "${ROOT_CA_FILE}" "${API_HOST}" "${API_SECURE_PORT}" controller
     kube::util::write_client_kubeconfig "${CONTROLPLANE_SUDO}" "${CERT_DIR}" "${ROOT_CA_FILE}" "${API_HOST}" "${API_SECURE_PORT}" scheduler
 
@@ -813,6 +817,10 @@ EOF
       done
     fi >>/tmp/kube-proxy.yaml
 
+    if [[ "${REUSE_CERTS}" != true ]]; then
+        generate_kubeproxy_certs
+    fi
+
     sudo "${GO_OUT}/hyperkube" proxy \
       --v=${LOG_LEVEL} \
       --config=/tmp/kube-proxy.yaml \
@@ -1014,7 +1022,9 @@ if [[ "${START_MODE}" != "kubeletonly" ]]; then
   if [[ "${EXTERNAL_CLOUD_PROVIDER:-}" == "true" ]]; then
     start_cloud_controller_manager
   fi
+  if [[ "${START_MODE}" != "nokubeproxy" ]]; then
     start_kubeproxy
+  fi
   start_kubescheduler
   start_kubedns
   if [[ "${ENABLE_NODELOCAL_DNS:-}" == "true" ]]; then