Add ipvs module loading logic to gce scripts

cluster/gce/gci/configure-helper.sh

@@ -1199,7 +1199,15 @@ function prepare-kube-proxy-manifest-variables {
     params+=" --feature-gates=${FEATURE_GATES}"
   fi
   if [[ "${KUBE_PROXY_MODE:-}" == "ipvs" ]];then
-    params+=" --proxy-mode=ipvs --feature-gates=SupportIPVSProxyMode=true"
+    sudo modprobe -a ip_vs ip_vs_rr ip_vs_wrr ip_vs_sh nf_conntrack_ipv4
+    if [[ $? -eq 0 ]];
+    then
+      params+=" --proxy-mode=ipvs"
+    else
+      # If IPVS modules are not present, make sure the node does not come up as
+      # healthy.
+      exit 1
+    fi
   fi
   params+=" --iptables-sync-period=1m --iptables-min-sync-period=10s --ipvs-sync-period=1m --ipvs-min-sync-period=10s"
   if [[ -n "${KUBEPROXY_TEST_ARGS:-}" ]]; then
@@ -2586,4 +2594,4 @@ if [[ "$#" -eq 1 && "${1}" == "--source-only" ]]; then
    :
 else
    main "${@}"
-fi
+fi