Added support for network specific enable ipv6 label

Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>

libnetwork/drivers/bridge/bridge.go

@@ -162,8 +162,8 @@ func (d *driver) Config(option map[string]interface{}) error {
 		return ErrConfigExists
 	}
 
-	genericData := option[netlabel.GenericData]
-	if genericData != nil {
+	genericData, ok := option[netlabel.GenericData]
+	if ok && genericData != nil {
 		switch opt := genericData.(type) {
 		case options.Generic:
 			opaqueConfig, err := options.GenerateFromModel(opt, &Configuration{})
@@ -178,6 +178,8 @@ func (d *driver) Config(option map[string]interface{}) error {
 		}
 
 		d.config = config
+	} else {
+		config = &Configuration{}
 	}
 
 	if config.EnableIPForwarding {
@@ -198,8 +200,8 @@ func (d *driver) getNetwork(id types.UUID) (*bridgeNetwork, error) {
 func parseNetworkOptions(option options.Generic) (*NetworkConfiguration, error) {
 	var config *NetworkConfiguration
 
-	genericData := option[netlabel.GenericData]
-	if genericData != nil {
+	genericData, ok := option[netlabel.GenericData]
+	if ok && genericData != nil {
 		switch opt := genericData.(type) {
 		case options.Generic:
 			opaqueConfig, err := options.GenerateFromModel(opt, &NetworkConfiguration{})
@@ -220,6 +222,10 @@ func parseNetworkOptions(option options.Generic) (*NetworkConfiguration, error)
 		config = &NetworkConfiguration{}
 	}
 
+	if _, ok := option[netlabel.EnableIPv6]; ok {
+		config.EnableIPv6 = option[netlabel.EnableIPv6].(bool)
+	}
+
 	return config, nil
 }
 

libnetwork/endpoint.go

@@ -409,7 +409,7 @@ func (ep *endpoint) setupDNS() error {
 	}
 
 	// replace any localhost/127.* but always discard IPv6 entries for now.
-	resolvConf, _ = resolvconf.FilterResolvDns(resolvConf, false)
+	resolvConf, _ = resolvconf.FilterResolvDns(resolvConf, ep.network.enableIPv6)
 	return ioutil.WriteFile(ep.container.config.resolvConfPath, resolvConf, 0644)
 }
 

libnetwork/libnetwork_test.go

@@ -1,6 +1,8 @@
 package libnetwork_test
 
 import (
+	"bytes"
+	"io/ioutil"
 	"net"
 	"os"
 	"testing"
@@ -30,16 +32,13 @@ func createTestNetwork(networkType, networkName string, option options.Generic,
 	genericOption := make(map[string]interface{})
 	genericOption[netlabel.GenericData] = option
 
-	genericNetOption := make(map[string]interface{})
-	genericNetOption[netlabel.GenericData] = netOption
-
 	err := controller.ConfigureNetworkDriver(networkType, genericOption)
 	if err != nil {
 		return nil, err
 	}
 
 	network, err := controller.NewNetwork(networkType, networkName,
-		libnetwork.NetworkOptionGeneric(genericNetOption))
+		libnetwork.NetworkOptionGeneric(netOption))
 	if err != nil {
 		return nil, err
 	}
@@ -775,3 +774,106 @@ func TestEndpointUpdateParent(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestEnableIPv6(t *testing.T) {
+	defer netutils.SetupTestNetNS(t)()
+
+	tmpResolvConf := []byte("search pommesfrites.fr\nnameserver 12.34.56.78\nnameserver 2001:4860:4860::8888")
+	//take a copy of resolv.conf for restoring after test completes
+	resolvConfSystem, err := ioutil.ReadFile("/etc/resolv.conf")
+	if err != nil {
+		t.Fatal(err)
+	}
+	//cleanup
+	defer func() {
+		if err := ioutil.WriteFile("/etc/resolv.conf", resolvConfSystem, 0644); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	netOption := options.Generic{
+		netlabel.EnableIPv6: true,
+	}
+
+	n, err := createTestNetwork("bridge", "testnetwork", options.Generic{}, netOption)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ep1, err := n.CreateEndpoint("ep1", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err := ioutil.WriteFile("/etc/resolv.conf", tmpResolvConf, 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	resolvConfPath := "/tmp/libnetwork_test/resolv.conf"
+
+	_, err = ep1.Join(containerID,
+		libnetwork.JoinOptionResolvConfPath(resolvConfPath))
+
+	content, err := ioutil.ReadFile(resolvConfPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Equal(content, tmpResolvConf) {
+		t.Fatalf("Expected %s, Got %s", string(tmpResolvConf), string(content))
+	}
+
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestNoEnableIPv6(t *testing.T) {
+	defer netutils.SetupTestNetNS(t)()
+
+	tmpResolvConf := []byte("search pommesfrites.fr\nnameserver 12.34.56.78\nnameserver 2001:4860:4860::8888")
+	expectedResolvConf := []byte("search pommesfrites.fr\nnameserver 12.34.56.78\n")
+	//take a copy of resolv.conf for restoring after test completes
+	resolvConfSystem, err := ioutil.ReadFile("/etc/resolv.conf")
+	if err != nil {
+		t.Fatal(err)
+	}
+	//cleanup
+	defer func() {
+		if err := ioutil.WriteFile("/etc/resolv.conf", resolvConfSystem, 0644); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	n, err := createTestNetwork("bridge", "testnetwork", options.Generic{}, options.Generic{})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ep1, err := n.CreateEndpoint("ep1", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err := ioutil.WriteFile("/etc/resolv.conf", tmpResolvConf, 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	resolvConfPath := "/tmp/libnetwork_test/resolv.conf"
+
+	_, err = ep1.Join(containerID,
+		libnetwork.JoinOptionResolvConfPath(resolvConfPath))
+
+	content, err := ioutil.ReadFile(resolvConfPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Equal(content, expectedResolvConf) {
+		t.Fatalf("Expected %s, Got %s", string(expectedResolvConf), string(content))
+	}
+
+	if err != nil {
+		t.Fatal(err)
+	}
+}

libnetwork/network.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/docker/docker/pkg/stringid"
 	"github.com/docker/libnetwork/driverapi"
+	"github.com/docker/libnetwork/pkg/netlabel"
 	"github.com/docker/libnetwork/pkg/options"
 	"github.com/docker/libnetwork/types"
 )
@@ -52,6 +53,7 @@ type network struct {
 	networkType string
 	id          types.UUID
 	driver      driverapi.Driver
+	enableIPv6  bool
 	endpoints   endpointTable
 	generic     options.Generic
 	sync.Mutex
@@ -83,6 +85,9 @@ type NetworkOption func(n *network)
 func NetworkOptionGeneric(generic map[string]interface{}) NetworkOption {
 	return func(n *network) {
 		n.generic = generic
+		if _, ok := generic[netlabel.EnableIPv6]; ok {
+			n.enableIPv6 = generic[netlabel.EnableIPv6].(bool)
+		}
 	}
 }