new file mode 100644

@@ -0,0 +1,42 @@

+package network

+

+import (

+	"fmt"

+	"os"

+	"syscall"

+

+	"github.com/dotcloud/docker/pkg/libcontainer"

+	"github.com/dotcloud/docker/pkg/system"

+)

+

+//  crosbymichael: could make a network strategy that instead of returning veth pair names it returns a pid to an existing network namespace

+type NetNS struct {

+}

+

+func (v *NetNS) Create(n *libcontainer.Network, nspid int, context libcontainer.Context) error {

+	nsname, exists := n.Context["nsname"]

+

+	if !exists {

+		return fmt.Errorf("nspath does not exist in network context")

+	}

+

+	context["nspath"] = fmt.Sprintf("/var/run/netns/%s", nsname)

+	return nil

+}

+

+func (v *NetNS) Initialize(config *libcontainer.Network, context libcontainer.Context) error {

+	nspath, exists := context["nspath"]

+	if !exists {

+		return fmt.Errorf("nspath does not exist in network context")

+	}

+

+	f, err := os.OpenFile(nspath, os.O_RDONLY, 0)

+	if err != nil {

+		return fmt.Errorf("failed get network namespace fd: %v", err)

+	}

+

+	if err := system.Setns(f.Fd(), syscall.CLONE_NEWNET); err != nil {

+		return fmt.Errorf("failed to setns current network namespace: %v", err)

+	}

+	return nil

+}

@@ -2,6 +2,7 @@ package network

 import (

 	"errors"

+

 	"github.com/dotcloud/docker/pkg/libcontainer"

 )

@@ -12,6 +13,7 @@ var (

 var strategies = map[string]NetworkStrategy{

 	"veth":     &Veth{},

 	"loopback": &Loopback{},

+	"netns":    &NetNS{},

 }

 // NetworkStrategy represents a specific network configuration for