libnetwork/netavark: allow same bridge name with different vlan

libnetwork/cni/config.go

@@ -86,7 +86,7 @@ func (n *cniNetwork) networkCreate(newNetwork *types.Network, defaultNet bool) (
 	switch newNetwork.Driver {
 	case types.BridgeNetworkDriver:
 		internalutil.MapDockerBridgeDriverOptions(newNetwork)
-		err = internalutil.CreateBridge(n, newNetwork, usedNetworks, n.defaultsubnetPools)
+		err = internalutil.CreateBridge(n, newNetwork, usedNetworks, n.defaultsubnetPools, true)
 		if err != nil {
 			return nil, err
 		}

libnetwork/internal/util/bridge.go

@@ -10,11 +10,13 @@ import (
 	"github.com/containers/common/pkg/config"
 )
 
-func CreateBridge(n NetUtil, network *types.Network, usedNetworks []*net.IPNet, subnetPools []config.SubnetPool) error {
+func CreateBridge(n NetUtil, network *types.Network, usedNetworks []*net.IPNet, subnetPools []config.SubnetPool, checkBridgeConflict bool) error {
 	if network.NetworkInterface != "" {
-		bridges := GetBridgeInterfaceNames(n)
-		if slices.Contains(bridges, network.NetworkInterface) {
-			return fmt.Errorf("bridge name %s already in use", network.NetworkInterface)
+		if checkBridgeConflict {
+			bridges := GetBridgeInterfaceNames(n)
+			if slices.Contains(bridges, network.NetworkInterface) {
+				return fmt.Errorf("bridge name %s already in use", network.NetworkInterface)
+			}
 		}
 		if !types.NameRegex.MatchString(network.NetworkInterface) {
 			return fmt.Errorf("bridge name %s invalid: %w", network.NetworkInterface, types.RegexError)

libnetwork/netavark/config.go

@@ -169,11 +169,9 @@ func (n *netavarkNetwork) networkCreate(newNetwork *types.Network, defaultNet bo
 	switch newNetwork.Driver {
 	case types.BridgeNetworkDriver:
 		internalutil.MapDockerBridgeDriverOptions(newNetwork)
-		err = internalutil.CreateBridge(n, newNetwork, usedNetworks, n.defaultsubnetPools)
-		if err != nil {
-			return nil, err
-		}
-		// validate the given options, we do not need them but just check to make sure they are valid
+
+		var vlan int
+		// validate the given options,
 		for key, value := range newNetwork.Options {
 			switch key {
 			case types.MTUOption:
@@ -183,7 +181,7 @@ func (n *netavarkNetwork) networkCreate(newNetwork *types.Network, defaultNet bo
 				}
 
 			case types.VLANOption:
-				_, err = internalutil.ParseVlan(value)
+				vlan, err = internalutil.ParseVlan(value)
 				if err != nil {
 					return nil, err
 				}
@@ -218,6 +216,17 @@ func (n *netavarkNetwork) networkCreate(newNetwork *types.Network, defaultNet bo
 				return nil, fmt.Errorf("unsupported bridge network option %s", key)
 			}
 		}
+
+		// If there is no vlan there should be no other config with the same bridge.
+		// However with vlan we want to allow that so that you can have different
+		// configs on the same bridge but different vlans
+		// https://github.com/containers/common/issues/2095
+		checkBridgeConflict := vlan == 0
+		err = internalutil.CreateBridge(n, newNetwork, usedNetworks, n.defaultsubnetPools, checkBridgeConflict)
+		if err != nil {
+			return nil, err
+		}
+
 	case types.MacVLANNetworkDriver, types.IPVLANNetworkDriver:
 		err = createIpvlanOrMacvlan(newNetwork)
 		if err != nil {

libnetwork/netavark/config_test.go

@@ -913,6 +913,27 @@ var _ = Describe("Config", func() {
 			Expect(err.Error()).To(ContainSubstring(`vlan ID -1 must be between 0 and 4094`))
 		})
 
+		It("create two networks with vlan option and same bridge", func() {
+			networkOpts := types.Network{
+				NetworkInterface: "br0",
+				Options: map[string]string{
+					types.VLANOption: "5",
+				},
+			}
+			network1, err := libpodNet.NetworkCreate(networkOpts, nil)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(network1.Driver).To(Equal("bridge"))
+			Expect(network1.Options).To(HaveKeyWithValue("vlan", "5"))
+
+			// set a new vlan
+			networkOpts.Options[types.VLANOption] = "99"
+
+			network2, err := libpodNet.NetworkCreate(networkOpts, nil)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(network2.Driver).To(Equal("bridge"))
+			Expect(network2.Options).To(HaveKeyWithValue("vlan", "99"))
+		})
+
 		It("create network with vrf option", func() {
 			network := types.Network{
 				Options: map[string]string{