Added "--router-id=" parameter. (#563)

For ipv6 it is not possible to use the ip address as router-id
and this parameter is required.

docs/user-guide.md

@@ -61,6 +61,7 @@ Usage of kube-router:
       --peer-router-multihop-ttl uint8   Enable eBGP multihop supports -- sets multihop-ttl. (Relevant only if ttl >= 2)
       --peer-router-passwords strings    Password for authenticating against the BGP peer defined with "--peer-router-ips".
       --peer-router-ports uints          The remote port of the external BGP to which all nodes will peer. If not set, default BGP port (179) will be used. (default [])
+      --router-id string                 BGP router-id. Must be specified in a ipv6 only cluster.
       --routes-sync-period duration      The delay between route updates and advertisements (e.g. '5s', '1m', '2h22m'). Must be greater than 0. (default 5m0s)
       --run-firewall                     Enables Network Policy -- sets up iptables to provide ingress firewall for pods. (default true)
       --run-router                       Enables Pod Networking -- Advertises and learns the routes to Pods via iBGP. (default true)

pkg/controllers/routing/network_routes_controller.go

@@ -60,6 +60,7 @@ type NetworkRoutingController struct {
 	nodeName                string
 	nodeSubnet              net.IPNet
 	nodeInterface           string
+	routerId                string
 	isIpv6                  bool
 	activeNodes             map[string]bool
 	mu                      sync.Mutex
@@ -676,7 +677,7 @@ func (nrc *NetworkRoutingController) startBgpServer() error {
 	global := &config.Global{
 		Config: config.GlobalConfig{
 			As:               nodeAsnNumber,
-			RouterId:         nrc.nodeIP.String(),
+			RouterId:         nrc.routerId,
 			LocalAddressList: localAddressList,
 			Port:             int32(nrc.bgpPort),
 		},
@@ -819,6 +820,15 @@ func NewNetworkRoutingController(clientset kubernetes.Interface,
 	nrc.nodeIP = nodeIP
 	nrc.isIpv6 = nodeIP.To4() == nil
 
+	if kubeRouterConfig.RouterId != "" {
+		nrc.routerId = kubeRouterConfig.RouterId
+	} else {
+		if nrc.isIpv6 {
+			return nil, errors.New("Router-id must be specified in ipv6 operation")
+		}
+		nrc.routerId = nrc.nodeIP.String()
+	}
+
 	// lets start with assumption we hace necessary IAM creds to access EC2 api
 	nrc.ec2IamAuthorized = true
 

pkg/options/options.go

@@ -47,6 +47,7 @@ type KubeRouterConfig struct {
 	PeerPasswords           []string
 	PeerPorts               []uint
 	PeerRouters             []net.IP
+	RouterId                string
 	RoutesSyncPeriod        time.Duration
 	RunFirewall             bool
 	RunRouter               bool
@@ -121,6 +122,7 @@ func (s *KubeRouterConfig) AddFlags(fs *pflag.FlagSet) {
 		"Enables the BGP Graceful Restart capability so that routes are preserved on unexpected restarts")
 	fs.Uint16Var(&s.BGPPort, "bgp-port", DEFAULT_BGP_PORT,
 		"The port open for incoming BGP connections and to use for connecting with other BGP peers.")
+	fs.StringVar(&s.RouterId, "router-id", "", "BGP router-id. Must be specified in a ipv6 only cluster.")
 	fs.BoolVar(&s.EnableCNI, "enable-cni", true,
 		"Enable CNI plugin. Disable if you want to use kube-router features alongside another CNI plugin.")
 	fs.BoolVar(&s.EnableiBGP, "enable-ibgp", true,