Add the advertise-service-cluster-ip-range parameter to summarize the announcement function of the service network segment, reduce the routing entries of the connected network devices, and support a larger BGP network.

docs/user-guide.md

@@ -40,6 +40,7 @@ Usage of kube-router:
       --advertise-external-ip                         Add External IP of service to the RIB so that it gets advertised to the BGP peers.
       --advertise-loadbalancer-ip                     Add LoadbBalancer IP of service status as set by the LB provider to the RIB so that it gets advertised to the BGP peers.
       --advertise-pod-cidr                            Add Node's POD cidr to the RIB so that it gets advertised to the BGP peers. (default true)
+      --advertise-service-cluster-ip-range string     Add Cluster IP range of the service to the rib so that it advertises the IP range to BGP peers. (make sure that the "advertise-cluster-ip=true" flag is also set.)
       --bgp-graceful-restart                          Enables the BGP Graceful Restart capability so that routes are preserved on unexpected restarts
       --bgp-graceful-restart-deferral-time duration   BGP Graceful restart deferral time according to RFC4724 4.1, maximum 18h. (default 6m0s)
       --bgp-port uint16                               The port open for incoming BGP connections and to use for connecting with other BGP peers. (default 179)
@@ -151,6 +152,8 @@ It does this by:
 To set the default for all services use the `--advertise-cluster-ip`,
 `--advertise-external-ip` and `--advertise-loadbalancer-ip` flags.
 
+If you want to advertise the Cluster IP range of the service to BGP peers to reduce the number of routes on the network devices, you can try to set the flags of `advertise-cluster-ip=true` and `advertise-service-cluster-ip-range=ip_range_cidr` at the same time. When this flags is set, Kube-router will add the service cluster IP range set by this parameter to the RIB, and send the routing advertisement of the service cluster IP range to the BGP peer. The purpose of this parameter is to reduce the number of service route entries sent by the Kube-router to the uplink network device. See <a href="large-networks03.md">large-networks03 documentation</a> for details.
+
 To selectively enable or disable this feature per-service use the
 `kube-router.io/service.advertise.clusterip`, `kube-router.io/service.advertise.externalip`
 and `kube-router.io/service.advertise.loadbalancerip` annotations.

pkg/controllers/routing/bgp_policies.go

@@ -45,9 +45,17 @@ func (nrc *NetworkRoutingController) AddPolicies() error {
 	// creates prefix set to represent all the advertisable IP associated with the services
 	advIPPrefixList := make([]config.Prefix, 0)
 	advIps, _, _ := nrc.getAllVIPs()
-	for _, ip := range advIps {
-		advIPPrefixList = append(advIPPrefixList, config.Prefix{IpPrefix: ip + "/32"})
+
+	//If the value of advertise-service-cluster-ip-range parameter is not empty, then the value of advertise-service-cluster-ip-range parameter is put into RIB, otherwise it will be done according to the original rules.
+	if len(nrc.advertiseServiceClusterIpRange) != 0 {
+		advIPPrefixList = append(advIPPrefixList, config.Prefix{IpPrefix: nrc.advertiseServiceClusterIpRange})
+	} else {
+		for _, ip := range advIps {
+			//housj add
+			advIPPrefixList = append(advIPPrefixList, config.Prefix{IpPrefix: ip + "/32"})
+		}
 	}
+
 	clusterIPPrefixSet, err := table.NewPrefixSet(config.PrefixSet{
 		PrefixSetName: "clusteripprefixset",
 		PrefixList:    advIPPrefixList,

pkg/controllers/routing/ecmp_vip.go

@@ -23,22 +23,34 @@ func (nrc *NetworkRoutingController) bgpAdvertiseVIP(vip string) error {
 		bgp.NewPathAttributeNextHop(nrc.nodeIP.String()),
 	}
 
-	glog.V(2).Infof("Advertising route: '%s/%s via %s' to peers", vip, strconv.Itoa(32), nrc.nodeIP.String())
-
-	_, err := nrc.bgpServer.AddPath("", []*table.Path{table.NewPath(nil, bgp.NewIPAddrPrefix(uint8(32),
-		vip), false, attrs, time.Now(), false)})
+	//If the value of advertise-service-cluster-ip-range parameter is not empty, then the value of advertise-service-cluster-ip-range parameter is put into RIB, otherwise it will be done according to the original rules.
+	var svcSubnet = vip
+	var svcCidrLen = 32
+	if len(nrc.advertiseServiceClusterIpRange) != 0 {
+		svcCidrStr := strings.Split(nrc.advertiseServiceClusterIpRange, "/")
+		svcSubnet = svcCidrStr[0]
+		svcCidrLen, _ = strconv.Atoi(svcCidrStr[1])
+	}
+	glog.V(2).Infof("Advertising route: '%s/%s via %s' to peers", svcSubnet, strconv.Itoa(svcCidrLen), nrc.nodeIP.String())
+	_, err := nrc.bgpServer.AddPath("", []*table.Path{table.NewPath(nil, bgp.NewIPAddrPrefix(uint8(svcCidrLen),
+		svcSubnet), false, attrs, time.Now(), false)})
 
 	return err
 }
 
 // bgpWithdrawVIP  unadvertises the service vip
 func (nrc *NetworkRoutingController) bgpWithdrawVIP(vip string) error {
-	glog.V(2).Infof("Withdrawing route: '%s/%s via %s' to peers", vip, strconv.Itoa(32), nrc.nodeIP.String())
-
-	pathList := []*table.Path{table.NewPath(nil, bgp.NewIPAddrPrefix(uint8(32),
-		vip), true, nil, time.Now(), false)}
 
-	err := nrc.bgpServer.DeletePath([]byte(nil), 0, "", pathList)
+	//If the value of the advertise-service-cluster-ip-range parameter is not empty, no operation will be performed, otherwise the original rules will be followed.
+	var err error
+	if len(nrc.advertiseServiceClusterIpRange) == 0 {
+		glog.V(2).Infof("Withdrawing route: '%s/%s via %s' to peers", vip, strconv.Itoa(32), nrc.nodeIP.String())
+		pathList := []*table.Path{table.NewPath(nil, bgp.NewIPAddrPrefix(uint8(32),
+			vip), true, nil, time.Now(), false)}
+		err = nrc.bgpServer.DeletePath([]byte(nil), 0, "", pathList)
+	} else {
+		err = nil
+	}
 
 	return err
 }

pkg/controllers/routing/network_routes_controller.go

@@ -78,6 +78,7 @@ type NetworkRoutingController struct {
 	enablePodEgress                bool
 	hostnameOverride               string
 	advertiseClusterIP             bool
+	advertiseServiceClusterIpRange string
 	advertiseExternalIP            bool
 	advertiseLoadBalancerIP        bool
 	advertisePodCidr               bool
@@ -885,6 +886,7 @@ func NewNetworkRoutingController(clientset kubernetes.Interface,
 	nrc.bgpServerStarted = false
 	nrc.disableSrcDstCheck = kubeRouterConfig.DisableSrcDstCheck
 	nrc.initSrcDstCheckDone = false
+	nrc.advertiseServiceClusterIpRange = kubeRouterConfig.AdvertiseServiceClusterIpRange
 
 	nrc.hostnameOverride = kubeRouterConfig.HostnameOverride
 	node, err := utils.GetNodeObject(clientset, nrc.hostnameOverride)

pkg/options/options.go

@@ -13,6 +13,7 @@ const DEFAULT_BGP_PORT = 179
 
 type KubeRouterConfig struct {
 	AdvertiseClusterIp             bool
+	AdvertiseServiceClusterIpRange string
 	AdvertiseExternalIp            bool
 	AdvertiseNodePodCidr           bool
 	AdvertiseLoadBalancerIp        bool
@@ -118,6 +119,8 @@ func (s *KubeRouterConfig) AddFlags(fs *pflag.FlagSet) {
 		"The delay between route updates and advertisements (e.g. '5s', '1m', '2h22m'). Must be greater than 0.")
 	fs.BoolVar(&s.AdvertiseClusterIp, "advertise-cluster-ip", false,
 		"Add Cluster IP of the service to the RIB so that it gets advertises to the BGP peers.")
+	fs.StringVar(&s.AdvertiseServiceClusterIpRange, "advertise-service-cluster-ip-range", s.AdvertiseServiceClusterIpRange,
+		"Add Cluster IP range of the service to the rib so that it advertises the IP range to BGP peers. (make sure that the \"advertise-cluster-ip=true\" flag is also set.)")
 	fs.BoolVar(&s.AdvertiseExternalIp, "advertise-external-ip", false,
 		"Add External IP of service to the RIB so that it gets advertised to the BGP peers.")
 	fs.BoolVar(&s.AdvertiseLoadBalancerIp, "advertise-loadbalancer-ip", false,