Merge pull request #351 from mrjana/docker1.7.0_integ

Honor driver side resolv.conf file

drivers/host/host.go

@@ -40,7 +40,11 @@ func (d *driver) EndpointOperInfo(nid, eid types.UUID) (map[string]interface{},
 
 // Join method is invoked when a Sandbox is attached to an endpoint.
 func (d *driver) Join(nid, eid types.UUID, sboxKey string, jinfo driverapi.JoinInfo, options map[string]interface{}) error {
-	return (jinfo.SetHostsPath("/etc/hosts"))
+	if err := jinfo.SetHostsPath("/etc/hosts"); err != nil {
+		return err
+	}
+
+	return jinfo.SetResolvConfPath("/etc/resolv.conf")
 }
 
 // Leave method is invoked when a Sandbox detaches from an endpoint.

endpoint.go

@@ -2,6 +2,7 @@ package libnetwork
 
 import (
 	"bytes"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
@@ -567,9 +568,19 @@ func (ep *endpoint) updateDNS(resolvConf []byte) error {
 	return os.Rename(tmpResolvFile.Name(), container.config.resolvConfPath)
 }
 
+func copyFile(src, dst string) error {
+	sBytes, err := ioutil.ReadFile(src)
+	if err != nil {
+		return err
+	}
+
+	return ioutil.WriteFile(dst, sBytes, 0644)
+}
+
 func (ep *endpoint) setupDNS() error {
 	ep.Lock()
 	container := ep.container
+	joinInfo := ep.joinInfo
 	ep.Unlock()
 
 	if container == nil {
@@ -586,6 +597,14 @@ func (ep *endpoint) setupDNS() error {
 		return err
 	}
 
+	if joinInfo.resolvConfPath != "" {
+		if err := copyFile(joinInfo.resolvConfPath, container.config.resolvConfPath); err != nil {
+			return fmt.Errorf("could not copy source resolv.conf file %s to %s: %v", joinInfo.resolvConfPath, container.config.resolvConfPath, err)
+		}
+
+		return nil
+	}
+
 	resolvConf, err := resolvconf.Get()
 	if err != nil {
 		return err

libnetwork_test.go

@@ -1119,6 +1119,74 @@ func TestEnableIPv6(t *testing.T) {
 	}
 }
 
+func TestResolvConfHost(t *testing.T) {
+	if !netutils.IsRunningInContainer() {
+		defer netutils.SetupTestNetNS(t)()
+	}
+
+	tmpResolvConf := []byte("search localhost.net\nnameserver 127.0.0.1\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)
+		}
+	}()
+
+	n, err := createTestNetwork("host", "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"
+	defer os.Remove(resolvConfPath)
+
+	_, err = ep1.Join(containerID,
+		libnetwork.JoinOptionResolvConfPath(resolvConfPath))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		err = ep1.Leave(containerID)
+		if err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	finfo, err := os.Stat(resolvConfPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fmode := (os.FileMode)(0644)
+	if finfo.Mode() != fmode {
+		t.Fatalf("Expected file mode %s, got %s", fmode.String(), finfo.Mode().String())
+	}
+
+	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))
+	}
+}
+
 func TestResolvConf(t *testing.T) {
 	if !netutils.IsRunningInContainer() {
 		defer netutils.SetupTestNetNS(t)()