Add dynamic veth name

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

pkg/libcontainer/network/veth.go

@@ -1,41 +0,0 @@
-package network
-
-import (
-	"fmt"
-	"github.com/dotcloud/docker/pkg/libcontainer"
-)
-
-// SetupVeth sets up an existing network namespace with the specified
-// network configuration.
-func SetupVeth(config *libcontainer.Network, tempVethName string) error {
-	if err := InterfaceDown(tempVethName); err != nil {
-		return fmt.Errorf("interface down %s %s", tempVethName, err)
-	}
-	if err := ChangeInterfaceName(tempVethName, "eth0"); err != nil {
-		return fmt.Errorf("change %s to eth0 %s", tempVethName, err)
-	}
-	if err := SetInterfaceIp("eth0", config.IP); err != nil {
-		return fmt.Errorf("set eth0 ip %s", err)
-	}
-
-	if err := SetMtu("eth0", config.Mtu); err != nil {
-		return fmt.Errorf("set eth0 mtu to %d %s", config.Mtu, err)
-	}
-	if err := InterfaceUp("eth0"); err != nil {
-		return fmt.Errorf("eth0 up %s", err)
-	}
-
-	if err := SetMtu("lo", config.Mtu); err != nil {
-		return fmt.Errorf("set lo mtu to %d %s", config.Mtu, err)
-	}
-	if err := InterfaceUp("lo"); err != nil {
-		return fmt.Errorf("lo up %s", err)
-	}
-
-	if config.Gateway != "" {
-		if err := SetDefaultGateway(config.Gateway); err != nil {
-			return fmt.Errorf("set gateway to %s %s", config.Gateway, err)
-		}
-	}
-	return nil
-}

pkg/libcontainer/nsinit/exec.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"github.com/dotcloud/docker/pkg/libcontainer"
 	"github.com/dotcloud/docker/pkg/libcontainer/network"
+	"github.com/dotcloud/docker/pkg/libcontainer/utils"
 	"github.com/dotcloud/docker/pkg/system"
 	"github.com/dotcloud/docker/pkg/term"
 	"io"
@@ -105,7 +106,14 @@ func createMasterAndConsole() (*os.File, string, error) {
 }
 
 func createVethPair() (name1 string, name2 string, err error) {
-	name1, name2 = "veth001", "veth002"
+	name1, err = utils.GenerateRandomName("dock", 4)
+	if err != nil {
+		return
+	}
+	name2, err = utils.GenerateRandomName("dock", 4)
+	if err != nil {
+		return
+	}
 	if err = network.CreateVethPair(name1, name2); err != nil {
 		return
 	}

pkg/libcontainer/nsinit/init.go

@@ -52,11 +52,14 @@ func main() {
 		log.Fatal(err)
 	}
 
-	data, err := ioutil.ReadAll(os.Stdin)
-	if err != nil {
-		log.Fatalf("error reading from stdin %s", err)
+	var tempVethName string
+	if container.Network != nil {
+		data, err := ioutil.ReadAll(os.Stdin)
+		if err != nil {
+			log.Fatalf("error reading from stdin %s", err)
+		}
+		tempVethName = string(data)
 	}
-	tempVethName := string(data)
 
 	// close pipes so that we can replace it with the pty
 	os.Stdin.Close()
@@ -73,7 +76,6 @@ func main() {
 	if err := dupSlave(slave); err != nil {
 		log.Fatalf("dup2 slave %s", err)
 	}
-
 	if _, err := system.Setsid(); err != nil {
 		log.Fatalf("setsid %s", err)
 	}
@@ -83,13 +85,11 @@ func main() {
 	if err := system.ParentDeathSignal(); err != nil {
 		log.Fatalf("parent deth signal %s", err)
 	}
-
 	if err := setupNewMountNamespace(rootfs, console, container.ReadonlyFs); err != nil {
 		log.Fatalf("setup mount namespace %s", err)
 	}
-
 	if container.Network != nil {
-		if err := setupNetworking(container, tempVethName); err != nil {
+		if err := setupNetworking(container.Network, tempVethName); err != nil {
 			log.Fatalf("setup networking %s", err)
 		}
 	}
@@ -174,6 +174,32 @@ func setLogFile(container *libcontainer.Container) error {
 	return nil
 }
 
-func setupNetworking(container *libcontainer.Container, tempVethName string) error {
-	return network.SetupVeth(container.Network, tempVethName)
+func setupNetworking(config *libcontainer.Network, tempVethName string) error {
+	if err := network.InterfaceDown(tempVethName); err != nil {
+		return fmt.Errorf("interface down %s %s", tempVethName, err)
+	}
+	if err := network.ChangeInterfaceName(tempVethName, "eth0"); err != nil {
+		return fmt.Errorf("change %s to eth0 %s", tempVethName, err)
+	}
+	if err := network.SetInterfaceIp("eth0", config.IP); err != nil {
+		return fmt.Errorf("set eth0 ip %s", err)
+	}
+	if err := network.SetMtu("eth0", config.Mtu); err != nil {
+		return fmt.Errorf("set eth0 mtu to %d %s", config.Mtu, err)
+	}
+	if err := network.InterfaceUp("eth0"); err != nil {
+		return fmt.Errorf("eth0 up %s", err)
+	}
+	if err := network.SetMtu("lo", config.Mtu); err != nil {
+		return fmt.Errorf("set lo mtu to %d %s", config.Mtu, err)
+	}
+	if err := network.InterfaceUp("lo"); err != nil {
+		return fmt.Errorf("lo up %s", err)
+	}
+	if config.Gateway != "" {
+		if err := network.SetDefaultGateway(config.Gateway); err != nil {
+			return fmt.Errorf("set gateway to %s %s", config.Gateway, err)
+		}
+	}
+	return nil
 }

pkg/libcontainer/utils/utils.go

@@ -4,30 +4,12 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"io"
-	"os"
-	"syscall"
 )
 
-func WaitOnPid(pid int) (exitcode int, err error) {
-	child, err := os.FindProcess(pid)
-	if err != nil {
-		return -1, err
-	}
-	state, err := child.Wait()
-	if err != nil {
-		return -1, err
-	}
-	return getExitCode(state), nil
-}
-
-func getExitCode(state *os.ProcessState) int {
-	return state.Sys().(syscall.WaitStatus).ExitStatus()
-}
-
-func GenerateRandomName(size int) (string, error) {
-	id := make([]byte, size)
+func GenerateRandomName(prefix string, size int) (string, error) {
+	id := make([]byte, 32)
 	if _, err := io.ReadFull(rand.Reader, id); err != nil {
 		return "", err
 	}
-	return hex.EncodeToString(id), nil
+	return prefix + hex.EncodeToString(id)[:size], nil
 }