fix(daemon): prepend host /etc/hosts instead of bind mounting

daemon/container.go

@@ -879,9 +879,17 @@ func (container *Container) initializeNetworking() error {
 			container.Config.Hostname = parts[0]
 			container.Config.Domainname = parts[1]
 		}
-		container.HostsPath = "/etc/hosts"
 
-		return container.buildHostnameFile()
+		content, err := ioutil.ReadFile("/etc/hosts")
+		if os.IsNotExist(err) {
+			return container.buildHostnameAndHostsFiles("")
+		}
+		if err != nil {
+			return err
+		}
+
+		container.HostsPath = container.getRootResourcePath("hosts")
+		return ioutil.WriteFile(container.HostsPath, content, 0644)
 	} else if container.hostConfig.NetworkMode.IsContainer() {
 		// we need to get the hosts files from the container to join
 		nc, err := container.getNetworkedContainer()

daemon/volumes.go

@@ -40,8 +40,11 @@ func setupMountsForContainer(container *Container) error {
 		{container.ResolvConfPath, "/etc/resolv.conf", false, true},
 	}
 
-	if container.HostnamePath != "" && container.HostsPath != "" {
+	if container.HostnamePath != "" {
 		mounts = append(mounts, execdriver.Mount{container.HostnamePath, "/etc/hostname", false, true})
+	}
+
+	if container.HostsPath != "" {
 		mounts = append(mounts, execdriver.Mount{container.HostsPath, "/etc/hosts", false, true})
 	}
 

integration-cli/docker_cli_links_test.go

@@ -3,10 +3,46 @@ package main
 import (
 	"fmt"
 	"github.com/dotcloud/docker/pkg/iptables"
+	"io/ioutil"
+	"os"
 	"os/exec"
+	"strings"
 	"testing"
 )
 
+func TestEtcHostsRegularFile(t *testing.T) {
+	runCmd := exec.Command(dockerBinary, "run", "--net=host", "busybox", "ls", "-la", "/etc/hosts")
+	out, _, _, err := runCommandWithStdoutStderr(runCmd)
+	errorOut(err, t, out)
+
+	if !strings.HasPrefix(out, "-") {
+		t.Errorf("/etc/hosts should be a regular file")
+	}
+
+	deleteAllContainers()
+
+	logDone("link - /etc/hosts is a regular file")
+}
+
+func TestEtcHostsContentMatch(t *testing.T) {
+	runCmd := exec.Command(dockerBinary, "run", "--net=host", "busybox", "cat", "/etc/hosts")
+	out, _, _, err := runCommandWithStdoutStderr(runCmd)
+	errorOut(err, t, out)
+
+	hosts, err := ioutil.ReadFile("/etc/hosts")
+	if os.IsNotExist(err) {
+		t.Skip("/etc/hosts does not exist, skip this test")
+	}
+
+	if out != string(hosts) {
+		t.Errorf("container")
+	}
+
+	deleteAllContainers()
+
+	logDone("link - /etc/hosts matches hosts copy")
+}
+
 func TestPingUnlinkedContainers(t *testing.T) {
 	runCmd := exec.Command(dockerBinary, "run", "--rm", "busybox", "sh", "-c", "ping -c 1 alias1 -W 1 && ping -c 1 alias2 -W 1")
 	exitCode, err := runCommand(runCmd)

integration-cli/docker_cli_run_test.go

@@ -438,7 +438,7 @@ func TestCreateVolume(t *testing.T) {
 
 	deleteAllContainers()
 
-	logDone("run - create docker mangaed volume")
+	logDone("run - create docker managed volume")
 }
 
 // Test that creating a volume with a symlink in its path works correctly. Test for #5152.