Remove daemon.VXSubnets duplicate code

Refactor daemon.V4Subnets and daemon.V6Subnets to limit duplication

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

daemon/cluster/cluster.go

@@ -89,8 +89,7 @@ var errSwarmCertificatesExpired = errors.New("Swarm certificates have expired. T
 // NetworkSubnetsProvider exposes functions for retrieving the subnets
 // of networks managed by Docker, so they can be filtered.
 type NetworkSubnetsProvider interface {
-	V4Subnets() []net.IPNet
-	V6Subnets() []net.IPNet
+	Subnets() ([]net.IPNet, []net.IPNet)
 }
 
 // Config provides values for Cluster.

daemon/cluster/listen_addr.go

@@ -162,8 +162,7 @@ func (c *Cluster) resolveSystemAddrViaSubnetCheck() (net.IP, error) {
 	var systemInterface string
 
 	// List Docker-managed subnets
-	v4Subnets := c.config.NetworkSubnetsProvider.V4Subnets()
-	v6Subnets := c.config.NetworkSubnetsProvider.V6Subnets()
+	v4Subnets, v6Subnets := c.config.NetworkSubnetsProvider.Subnets()
 
 ifaceLoop:
 	for _, intf := range interfaces {

daemon/daemon.go

@@ -878,40 +878,28 @@ func (daemon *Daemon) Unmount(container *container.Container) error {
 	return nil
 }
 
-// V4Subnets returns the IPv4 subnets of networks that are managed by Docker.
-func (daemon *Daemon) V4Subnets() []net.IPNet {
-	var subnets []net.IPNet
+// Subnets return the IPv4 and IPv6 subnets of networks that are manager by Docker.
+func (daemon *Daemon) Subnets() ([]net.IPNet, []net.IPNet) {
+	var v4Subnets []net.IPNet
+	var v6Subnets []net.IPNet
 
 	managedNetworks := daemon.netController.Networks()
 
 	for _, managedNetwork := range managedNetworks {
-		v4Infos, _ := managedNetwork.Info().IpamInfo()
-		for _, v4Info := range v4Infos {
-			if v4Info.IPAMData.Pool != nil {
-				subnets = append(subnets, *v4Info.IPAMData.Pool)
+		v4infos, v6infos := managedNetwork.Info().IpamInfo()
+		for _, info := range v4infos {
+			if info.IPAMData.Pool != nil {
+				v4Subnets = append(v4Subnets, *info.IPAMData.Pool)
 			}
 		}
-	}
-
-	return subnets
-}
-
-// V6Subnets returns the IPv6 subnets of networks that are managed by Docker.
-func (daemon *Daemon) V6Subnets() []net.IPNet {
-	var subnets []net.IPNet
-
-	managedNetworks := daemon.netController.Networks()
-
-	for _, managedNetwork := range managedNetworks {
-		_, v6Infos := managedNetwork.Info().IpamInfo()
-		for _, v6Info := range v6Infos {
-			if v6Info.IPAMData.Pool != nil {
-				subnets = append(subnets, *v6Info.IPAMData.Pool)
+		for _, info := range v6infos {
+			if info.IPAMData.Pool != nil {
+				v6Subnets = append(v6Subnets, *info.IPAMData.Pool)
 			}
 		}
 	}
 
-	return subnets
+	return v4Subnets, v6Subnets
 }
 
 // GraphDriverName returns the name of the graph driver used by the layer.Store