services-controller: Add LoadBalancer Service support (#53)

* Allow LoadBalancer Service type
* Update docs

README.md

@@ -120,10 +120,10 @@ leverages standard Linux technologies **iptables, ipvs/lvs, ipset, iproute2**
 [Kubernetes network services proxy with IPVS/LVS](https://cloudnativelabs.github.io/post/2017-05-10-kube-network-service-proxy/)
 
 Kube-router uses IPVS/LVS technology built in Linux to provide L4 load
-balancing. Each **ClusterIP** and **NodePort** Kubernetes Service type is
-configured as an IPVS virtual service. Each Service Endpoint is configured as
-real server to the virtual service.  The standard **ipvsadm** tool can be used
-to verify the configuration and monitor the active connections.
+balancing. Each **ClusterIP**, **NodePort**, and **LoadBalancer** Kubernetes
+Service type is configured as an IPVS virtual service. Each Service Endpoint is
+configured as real server to the virtual service.  The standard **ipvsadm** tool
+can be used to verify the configuration and monitor the active connections.
 
 Below is example set of Services on Kubernetes:
 

app/controllers/network_routes_controller.go

@@ -118,7 +118,7 @@ func (nrc *NetworkRoutingController) Run(stopCh <-chan struct{}, wg *sync.WaitGr
 		if nrc.advertiseClusterIp {
 			glog.Infof("Advertising cluster ips")
 			for _, svc := range watchers.ServiceWatcher.List() {
-				if svc.Spec.Type == "ClusterIP" || svc.Spec.Type == "NodePort" {
+				if svc.Spec.Type == "ClusterIP" || svc.Spec.Type == "NodePort" || svc.Spec.Type == "LoadBalancer" {
 
 					// skip headless services
 					if svc.Spec.ClusterIP == "None" || svc.Spec.ClusterIP == "" {

app/controllers/network_services_controller.go

@@ -34,7 +34,7 @@ var (
 )
 
 // Network services controller enables local node as network service proxy through IPVS/LVS.
-// Support only Kuberntes network services of type NodePort, ClusterIP. For each service a
+// Support only Kubernetes network services of type NodePort, ClusterIP, and LoadBalancer. For each service a
 // IPVS service is created and for each service endpoint a server is added to the IPVS service.
 // As services and endpoints are updated, network service controller gets the updates from
 // the kubernetes api server and syncs the ipvs configuration to reflect state of services
@@ -317,7 +317,7 @@ func buildServicesInfo() serviceInfoMap {
 			continue
 		}
 
-		if svc.Spec.Type == "LoadBalancer" || svc.Spec.Type == "ExternalName" {
+		if svc.Spec.Type == "ExternalName" {
 			glog.Infof("Skipping service name:%s namespace:%s due to service Type=%s", svc.Name, svc.Namespace, svc.Spec.Type)
 			continue
 		}

app/options/options.go

@@ -63,5 +63,5 @@ func (s *KubeRouterConfig) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&s.PeerAsn, "peer-asn", s.PeerAsn, "ASN number of the BGP peer to which cluster nodes will advertise cluster ip and node's pod cidr")
 	fs.BoolVar(&s.FullMeshMode, "nodes-full-mesh", s.FullMeshMode, "When enabled each node in the cluster will setup BGP peer with rest of the nodes. True by default")
 	fs.StringVar(&s.HostnameOverride, "hostname-override", s.HostnameOverride, "If non-empty, will use this string as identification instead of the actual hostname.")
-	fs.BoolVar(&s.GlobalHairpinMode, "hairpin-mode", s.GlobalHairpinMode, "Adds iptable rules for every ClusterIP Service Endpoint to support hairpin traffic. False by default")
+	fs.BoolVar(&s.GlobalHairpinMode, "hairpin-mode", s.GlobalHairpinMode, "Adds iptable rules for every Service Endpoint to support hairpin traffic. False by default")
 }