@@ -434,17 +434,23 @@ func postImagesPush(srv *Server, version float64, w http.ResponseWriter, r *http

 func postContainersCreate(srv *Server, version float64, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

 	config := &Config{}

+	out := &APIRun{}

+

 	if err := json.NewDecoder(r.Body).Decode(config); err != nil {

 		return err

 	}

+

+	if len(config.Dns) == 0 && len(srv.runtime.Dns) == 0 && utils.CheckLocalDns() {

+		out.Warnings = append(out.Warnings, fmt.Sprintf("WARNING: Docker detected local DNS server on resolv.conf. Using default external servers: %v", defaultDns))

+		config.Dns = defaultDns

+	}

+

 	id, err := srv.ContainerCreate(config)

 	if err != nil {

 		return err

 	}

+	out.ID = id

-	out := &APIRun{

-		ID: id,

-	}

 	if config.Memory > 0 && !srv.runtime.capabilities.MemoryLimit {

 		log.Println("WARNING: Your kernel does not support memory limit capabilities. Limitation discarded.")

 		out.Warnings = append(out.Warnings, "Your kernel does not support memory limit capabilities. Limitation discarded.")

@@ -453,6 +459,7 @@ func postContainersCreate(srv *Server, version float64, w http.ResponseWriter, r

 		log.Println("WARNING: Your kernel does not support swap limit capabilities. Limitation discarded.")

 		out.Warnings = append(out.Warnings, "Your kernel does not support memory swap capabilities. Limitation discarded.")

 	}

+

 	b, err := json.Marshal(out)

 	if err != nil {

 		return err

@@ -2,11 +2,14 @@ package docker

 import (

 	"fmt"

+	"github.com/dotcloud/docker/utils"

 	"os"

 	"path"

 	"time"

 )

+var defaultDns = []string{"8.8.8.8", "8.8.4.4"}

+

 type Builder struct {

 	runtime      *Runtime

 	repositories *TagStore

@@ -66,15 +69,26 @@ func (builder *Builder) Create(config *Config) (*Container, error) {

 		return nil, err

 	}

+	if len(config.Dns) == 0 && len(builder.runtime.Dns) == 0 && utils.CheckLocalDns() {

+		//"WARNING: Docker detected local DNS server on resolv.conf. Using default external servers: %v", defaultDns

+		builder.runtime.Dns = defaultDns

+	}

+

 	// If custom dns exists, then create a resolv.conf for the container

-	if len(config.Dns) > 0 {

+	if len(config.Dns) > 0 || len(builder.runtime.Dns) > 0 {

+		var dns []string

+		if len(config.Dns) > 0 {

+			dns = config.Dns

+		} else {

+			dns = builder.runtime.Dns

+		}

 		container.ResolvConfPath = path.Join(container.root, "resolv.conf")

 		f, err := os.Create(container.ResolvConfPath)

 		if err != nil {

 			return nil, err

 		}

 		defer f.Close()

-		for _, dns := range config.Dns {

+		for _, dns := range dns {

 			if _, err := f.Write([]byte("nameserver " + dns + "\n")); err != nil {

 				return nil, err

 			}

@@ -34,6 +34,7 @@ func main() {

 	pidfile := flag.String("p", "/var/run/docker.pid", "File containing process PID")

 	flHost := flag.String("H", fmt.Sprintf("%s:%d", host, port), "Host:port to bind/connect to")

 	flEnableCors := flag.Bool("api-enable-cors", false, "Enable CORS requests in the remote api.")

+	flDns := flag.String("dns", "", "Set custom dns servers")

 	flag.Parse()

 	if *bridgeName != "" {

 		docker.NetworkBridgeIface = *bridgeName

@@ -66,7 +67,7 @@ func main() {

 			flag.Usage()

 			return

 		}

-		if err := daemon(*pidfile, host, port, *flAutoRestart, *flEnableCors); err != nil {

+		if err := daemon(*pidfile, host, port, *flAutoRestart, *flEnableCors, *flDns); err != nil {

 			log.Fatal(err)

 			os.Exit(-1)

 		}

@@ -105,7 +106,7 @@ func removePidFile(pidfile string) {

 	}

 }

-func daemon(pidfile, addr string, port int, autoRestart, enableCors bool) error {

+func daemon(pidfile, addr string, port int, autoRestart, enableCors bool, flDns string) error {

 	if addr != "127.0.0.1" {

 		log.Println("/!\\ DON'T BIND ON ANOTHER IP ADDRESS THAN 127.0.0.1 IF YOU DON'T KNOW WHAT YOU'RE DOING /!\\")

 	}

@@ -122,8 +123,11 @@ func daemon(pidfile, addr string, port int, autoRestart, enableCors bool) error

 		removePidFile(pidfile)

 		os.Exit(0)

 	}()

-

-	server, err := docker.NewServer(autoRestart, enableCors)

+	var dns []string

+	if flDns != "" {

+		dns = []string{flDns}

+	}

+	server, err := docker.NewServer(autoRestart, enableCors, dns)

 	if err != nil {

 		return err

 	}

@@ -32,6 +32,7 @@ type Runtime struct {

 	autoRestart    bool

 	volumes        *Graph

 	srv            *Server

+	Dns            []string

 }

 var sysInitPath string

@@ -245,11 +246,12 @@ func (runtime *Runtime) UpdateCapabilities(quiet bool) {

 }

 // FIXME: harmonize with NewGraph()

-func NewRuntime(autoRestart bool) (*Runtime, error) {

+func NewRuntime(autoRestart bool, dns []string) (*Runtime, error) {

 	runtime, err := NewRuntimeFromDirectory("/var/lib/docker", autoRestart)

 	if err != nil {

 		return nil, err

 	}

+	runtime.Dns = dns

 	if k, err := utils.GetKernelVersion(); err != nil {

 		log.Printf("WARNING: %s\n", err)

@@ -978,11 +978,11 @@ func (srv *Server) ImageInspect(name string) (*Image, error) {

 	return nil, fmt.Errorf("No such image: %s", name)

 }

-func NewServer(autoRestart, enableCors bool) (*Server, error) {

+func NewServer(autoRestart, enableCors bool, dns ListOpts) (*Server, error) {

 	if runtime.GOARCH != "amd64" {

 		log.Fatalf("The docker runtime currently only supports amd64 (not %s). This will change in the future. Aborting.", runtime.GOARCH)

 	}

-	runtime, err := NewRuntime(autoRestart)

+	runtime, err := NewRuntime(autoRestart, dns)

 	if err != nil {

 		return nil, err

 	}

@@ -70,7 +70,7 @@ type progressReader struct {

 	readProgress int           // How much has been read so far (bytes)

 	lastUpdate   int           // How many bytes read at least update

 	template     string        // Template to print. Default "%v/%v (%v)"

-	sf *StreamFormatter

+	sf           *StreamFormatter

 }

 func (r *progressReader) Read(p []byte) (n int, err error) {

@@ -103,7 +103,7 @@ func (r *progressReader) Close() error {

 	return io.ReadCloser(r.reader).Close()

 }

 func ProgressReader(r io.ReadCloser, size int, output io.Writer, template []byte, sf *StreamFormatter) *progressReader {

-      	tpl := string(template)

+	tpl := string(template)

 	if tpl == "" {

 		tpl = string(sf.FormatProgress("", "%v/%v (%v)"))

 	}

@@ -599,7 +599,7 @@ func (sf *StreamFormatter) FormatStatus(format string, a ...interface{}) []byte

 	sf.used = true

 	str := fmt.Sprintf(format, a...)

 	if sf.json {

-		b, err := json.Marshal(&JSONMessage{Status:str});

+		b, err := json.Marshal(&JSONMessage{Status: str})

 		if err != nil {

 			return sf.FormatError(err)

 		}

@@ -611,7 +611,7 @@ func (sf *StreamFormatter) FormatStatus(format string, a ...interface{}) []byte

 func (sf *StreamFormatter) FormatError(err error) []byte {

 	sf.used = true

 	if sf.json {

-		if b, err := json.Marshal(&JSONMessage{Error:err.Error()}); err == nil {

+		if b, err := json.Marshal(&JSONMessage{Error: err.Error()}); err == nil {

 			return b

 		}

 		return []byte("{\"error\":\"format error\"}")

@@ -622,10 +622,10 @@ func (sf *StreamFormatter) FormatError(err error) []byte {

 func (sf *StreamFormatter) FormatProgress(action, str string) []byte {

 	sf.used = true

 	if sf.json {

-		b, err := json.Marshal(&JSONMessage{Status: action, Progress:str})

+		b, err := json.Marshal(&JSONMessage{Status: action, Progress: str})

 		if err != nil {

-                        return nil

-                }

+			return nil

+		}

 		return b

 	}

 	return []byte(action + " " + str + "\r")

@@ -634,3 +634,20 @@ func (sf *StreamFormatter) FormatProgress(action, str string) []byte {

 func (sf *StreamFormatter) Used() bool {

 	return sf.used

 }

+

+func CheckLocalDns() bool {

+	resolv, err := ioutil.ReadFile("/etc/resolv.conf")

+	if err != nil {

+		Debugf("Error openning resolv.conf: %s", err)

+		return false

+	}

+	for _, ip := range []string{

+		"127.0.0.1",

+		"127.0.1.1",

+	} {

+		if strings.Contains(string(resolv), ip) {

+			return true

+		}

+	}

+	return false

+}