Use --overlay-type={subnet,full} instead of --full-overlay={true,false}

docs/user-guide.md

@@ -52,7 +52,6 @@ Usage of kube-router:
       --enable-overlay                   When enable-overlay is set to true, IP-in-IP tunneling is used for pod-to-pod networking across nodes in different subnets. When set to false no tunneling is used and routing infrastructure is expected to route traffic for pod-to-pod networking across nodes in different subnets (default true)
       --enable-pod-egress                SNAT traffic from Pods to destinations outside the cluster. (default true)
       --enable-pprof                     Enables pprof for debugging performance and memory leak issues.
-      --full-overlay                     When full-overlay is set to true, it changes "--enable-overlay=true" default behavior so that IP-in-IP tunneling is used for pod-to-pod networking across nodes regardless of the subnet the nodes are in. When set to false, the default, default "--enable-overlay=true" behavior is used
       --hairpin-mode                     Add iptables rules for every Service Endpoint to support hairpin traffic.
       --health-port uint16               Health check port, 0 = Disabled (default 20244)
   -h, --help                             Print usage information.
@@ -66,6 +65,7 @@ Usage of kube-router:
       --metrics-port uint16              Prometheus metrics port, (Default 0, Disabled)
       --nodeport-bindon-all-ip           For service of NodePort type create IPVS service that listens on all IP's of the node.
       --nodes-full-mesh                  Each node in the cluster will setup BGP peering with rest of the nodes. (default true)
+      --overlay-type string              Possible values: subnet,full - When set to "subnet", the default, default "--enable-overlay=true" behavior is used. When set to "full", it changes "--enable-overlay=true" default behavior so that IP-in-IP tunneling is used for pod-to-pod networking across nodes regardless of the subnet the nodes are in. (default "subnet")
       --override-nexthop                 Override the next-hop in bgp routes sent to peers with the local ip.
       --peer-router-asns uints           ASN numbers of the BGP peer to which cluster nodes will advertise cluster ip and node's pod cidr. (default [])
       --peer-router-ips ipSlice          The ip address of the external router to which all nodes will peer and advertise the cluster ip and pod cidr's. (default [])

pkg/controllers/routing/network_routes_controller.go

@@ -91,7 +91,7 @@ type NetworkRoutingController struct {
 	bgpGracefulRestart      bool
 	ipSetHandler            *utils.IPSet
 	enableOverlays          bool
-	fullOverlay             bool
+	overlayType             string
 	peerMultihopTTL         uint8
 	MetricsEnabled          bool
 	bgpServerStarted        bool
@@ -414,8 +414,8 @@ func (nrc *NetworkRoutingController) injectRoute(path *table.Path) error {
 	tunnelName := generateTunnelName(nexthop.String())
 	sameSubnet := nrc.nodeSubnet.Contains(nexthop)
 
-	// cleanup route and tunnel if overlay is disabled or node is in same subnet and full overlay is disabled
-	if !nrc.enableOverlays || (sameSubnet && !nrc.fullOverlay) {
+	// cleanup route and tunnel if overlay is disabled or node is in same subnet and overlay-type is set to 'subnet'
+	if !nrc.enableOverlays || (sameSubnet && nrc.overlayType == "subnet") {
 		glog.Infof("Cleaning up old routes if there are any")
 		routes, err := netlink.RouteListFiltered(nl.FAMILY_ALL, &netlink.Route{
 			Dst: dst, Protocol: 0x11,
@@ -438,9 +438,9 @@ func (nrc *NetworkRoutingController) injectRoute(path *table.Path) error {
 		}
 	}
 
-	// create IPIP tunnels only when node is not in same subnet or full overlay is true
+	// create IPIP tunnels only when node is not in same subnet or overlay-type is set to 'full'
 	// prevent creation when --override-nexthop=true as well
-	if (!sameSubnet || nrc.fullOverlay) && !nrc.overrideNextHop {
+	if (!sameSubnet || nrc.overlayType == "full") && !nrc.overrideNextHop {
 		// create ip-in-ip tunnel and inject route as overlay is enabled
 		var link netlink.Link
 		var err error
@@ -930,7 +930,7 @@ func NewNetworkRoutingController(clientset kubernetes.Interface,
 	nrc.advertiseLoadBalancerIP = kubeRouterConfig.AdvertiseLoadBalancerIp
 	nrc.advertisePodCidr = kubeRouterConfig.AdvertiseNodePodCidr
 	nrc.enableOverlays = kubeRouterConfig.EnableOverlay
-	nrc.fullOverlay = kubeRouterConfig.FullOverlay
+	nrc.overlayType = kubeRouterConfig.OverlayType
 
 	nrc.bgpPort = kubeRouterConfig.BGPPort
 

pkg/options/options.go

@@ -29,7 +29,7 @@ type KubeRouterConfig struct {
 	EnablePodEgress         bool
 	EnablePprof             bool
 	FullMeshMode            bool
-	FullOverlay             bool
+	OverlayType             string
 	GlobalHairpinMode       bool
 	HealthPort              uint16
 	HelpRequested           bool
@@ -66,6 +66,7 @@ func NewKubeRouterConfig() *KubeRouterConfig {
 		IPTablesSyncPeriod: 5 * time.Minute,
 		RoutesSyncPeriod:   5 * time.Minute,
 		EnableOverlay:      true,
+		OverlayType:        "subnet",
 	}
 }
 
@@ -138,9 +139,10 @@ func (s *KubeRouterConfig) AddFlags(fs *pflag.FlagSet) {
 	fs.BoolVar(&s.EnableOverlay, "enable-overlay", true,
 		"When enable-overlay is set to true, IP-in-IP tunneling is used for pod-to-pod networking across nodes in different subnets. "+
 			"When set to false no tunneling is used and routing infrastructure is expected to route traffic for pod-to-pod networking across nodes in different subnets")
-	fs.BoolVar(&s.FullOverlay, "full-overlay", false,
-		"When full-overlay is set to true, it changes \"--enable-overlay=true\" default behavior so that IP-in-IP tunneling is used for pod-to-pod networking across nodes regardless of the subnet the nodes are in. "+
-			"When set to false, the default, default \"--enable-overlay=true\" behavior is used")
+	fs.StringVar(&s.OverlayType, "overlay-type", s.OverlayType,
+		"Possible values: subnet,full - "+
+			"When set to \"subnet\", the default, default \"--enable-overlay=true\" behavior is used. "+
+			"When set to \"full\", it changes \"--enable-overlay=true\" default behavior so that IP-in-IP tunneling is used for pod-to-pod networking across nodes regardless of the subnet the nodes are in.")
 	fs.StringSliceVar(&s.PeerPasswords, "peer-router-passwords", s.PeerPasswords,
 		"Password for authenticating against the BGP peer defined with \"--peer-router-ips\".")
 	fs.BoolVar(&s.EnablePprof, "enable-pprof", false,