fix(vrf): create bridge and vxlan only if VNI value is not empty

Fixes #105

Signed-off-by: Boris Glimcher <Boris.Glimcher@emc.com>

pkg/evpn/vrf.go

@@ -81,52 +81,57 @@ func (s *Server) CreateVrf(_ context.Context, in *pb.CreateVrfRequest) (*pb.Vrf,
 	// TODO: Add low-prio default route. Otherwise a miss leads to lookup in the next higher table
 	// Example: ip route add throw default table <routing-table-number> proto evpn-gw-br metric 9999
 
-	// Example: ip link add br100 type bridge
-	bridgeName := fmt.Sprintf("br%d", in.Vrf.Spec.Vni)
-	bridge := &netlink.Bridge{LinkAttrs: netlink.LinkAttrs{Name: bridgeName}}
-	if err := netlink.LinkAdd(bridge); err != nil {
-		fmt.Printf("Failed to create Bridge link: %v", err)
-		return nil, err
-	}
-	// Example: ip link set br100 master blue addrgenmode none
-	if err := netlink.LinkSetMaster(bridge, vrf); err != nil {
-		fmt.Printf("Failed to add Bridge to VRF: %v", err)
-		return nil, err
-	}
-	// Example: ip link set br100 addr aa:bb:cc:00:00:02
+	// generate random mac, since it is not part of user facing API
 	mac, err := generateRandMAC()
 	if err != nil {
 		fmt.Printf("Failed to generate random MAC: %v", err)
 		return nil, err
 	}
-	if err := netlink.LinkSetHardwareAddr(bridge, mac); err != nil {
-		fmt.Printf("Failed to set MAC on Bridge link: %v", err)
-		return nil, err
-	}
-	// Example: ip link set br100 up
-	if err := netlink.LinkSetUp(bridge); err != nil {
-		fmt.Printf("Failed to up Bridge link: %v", err)
-		return nil, err
-	}
-	// Example: ip link add vni100 type vxlan local 10.0.0.4 dstport 4789 id 100 nolearning
-	vxlanName := fmt.Sprintf("vni%d", in.Vrf.Spec.Vni)
-	myip := make(net.IP, 4)
-	binary.BigEndian.PutUint32(myip, in.Vrf.Spec.VtepIpPrefix.Addr.GetV4Addr())
-	// TODO: take Port from proto instead of hard-coded
-	vxlan := &netlink.Vxlan{LinkAttrs: netlink.LinkAttrs{Name: vxlanName}, VxlanId: int(in.Vrf.Spec.Vni), Port: 4789, Learning: false, SrcAddr: myip}
-	if err := netlink.LinkAdd(vxlan); err != nil {
-		fmt.Printf("Failed to create Vxlan link: %v", err)
-		return nil, err
-	}
-	// Example: ip link set vni100 master br100 addrgenmode none
-	if err := netlink.LinkSetMaster(vxlan, bridge); err != nil {
-		fmt.Printf("Failed to add Vxlan to bridge: %v", err)
-		return nil, err
-	}
-	// Example: ip link set vni100 up
-	if err := netlink.LinkSetUp(vxlan); err != nil {
-		fmt.Printf("Failed to up Vxlan link: %v", err)
-		return nil, err
+
+	// create bridge and vxlan only if VNI value is not empty
+	if in.Vrf.Spec.Vni > 0 {
+		// Example: ip link add br100 type bridge
+		bridgeName := fmt.Sprintf("br%d", in.Vrf.Spec.Vni)
+		bridge := &netlink.Bridge{LinkAttrs: netlink.LinkAttrs{Name: bridgeName}}
+		if err := netlink.LinkAdd(bridge); err != nil {
+			fmt.Printf("Failed to create Bridge link: %v", err)
+			return nil, err
+		}
+		// Example: ip link set br100 master blue addrgenmode none
+		if err := netlink.LinkSetMaster(bridge, vrf); err != nil {
+			fmt.Printf("Failed to add Bridge to VRF: %v", err)
+			return nil, err
+		}
+		// Example: ip link set br100 addr aa:bb:cc:00:00:02
+		if err := netlink.LinkSetHardwareAddr(bridge, mac); err != nil {
+			fmt.Printf("Failed to set MAC on Bridge link: %v", err)
+			return nil, err
+		}
+		// Example: ip link set br100 up
+		if err := netlink.LinkSetUp(bridge); err != nil {
+			fmt.Printf("Failed to up Bridge link: %v", err)
+			return nil, err
+		}
+		// Example: ip link add vni100 type vxlan local 10.0.0.4 dstport 4789 id 100 nolearning
+		vxlanName := fmt.Sprintf("vni%d", in.Vrf.Spec.Vni)
+		myip := make(net.IP, 4)
+		binary.BigEndian.PutUint32(myip, in.Vrf.Spec.VtepIpPrefix.Addr.GetV4Addr())
+		// TODO: take Port from proto instead of hard-coded
+		vxlan := &netlink.Vxlan{LinkAttrs: netlink.LinkAttrs{Name: vxlanName}, VxlanId: int(in.Vrf.Spec.Vni), Port: 4789, Learning: false, SrcAddr: myip}
+		if err := netlink.LinkAdd(vxlan); err != nil {
+			fmt.Printf("Failed to create Vxlan link: %v", err)
+			return nil, err
+		}
+		// Example: ip link set vni100 master br100 addrgenmode none
+		if err := netlink.LinkSetMaster(vxlan, bridge); err != nil {
+			fmt.Printf("Failed to add Vxlan to bridge: %v", err)
+			return nil, err
+		}
+		// Example: ip link set vni100 up
+		if err := netlink.LinkSetUp(vxlan); err != nil {
+			fmt.Printf("Failed to up Vxlan link: %v", err)
+			return nil, err
+		}
 	}
 	response := proto.Clone(in.Vrf).(*pb.Vrf)
 	response.Status = &pb.VrfStatus{LocalAs: 4, RoutingTable: tableID, Rmac: mac}