@@ -223,6 +223,21 @@ func prettyPrintInfo(dockerCli *command.DockerCli, info types.Info) error {

 		for _, attribute := range info.Labels {

 			fmt.Fprintf(dockerCli.Out(), " %s\n", attribute)

 		}

+		// TODO: Engine labels with duplicate keys has been deprecated in 1.13 and will be error out

+		// after 3 release cycles (1.16). For now, a WARNING will be generated. The following will

+		// be removed eventually.

+		labelMap := map[string]string{}

+		for _, label := range info.Labels {

+			stringSlice := strings.SplitN(label, "=", 2)

+			if len(stringSlice) > 1 {

+				// If there is a conflict we will throw out an warning

+				if v, ok := labelMap[stringSlice[0]]; ok && v != stringSlice[1] {

+					fmt.Fprintln(dockerCli.Err(), "WARNING: labels with duplicate keys and conflicting values have been deprecated")

+					break

+				}

+				labelMap[stringSlice[0]] = stringSlice[1]

+			}

+		}

 	}

 	ioutils.FprintfIfTrue(dockerCli.Out(), "Experimental: %v\n", info.ExperimentalBuild)

@@ -396,6 +396,23 @@ func loadDaemonCliConfig(opts daemonOptions) (*daemon.Config, error) {

 		return nil, err

 	}

+	// Labels of the docker engine used to allow multiple values associated with the same key.

+	// This is deprecated in 1.13, and, be removed after 3 release cycles.

+	// The following will check the conflict of labels, and report a warning for deprecation.

+	//

+	// TODO: After 3 release cycles (1.16) an error will be returned, and labels will be

+	// sanitized to consolidate duplicate key-value pairs (config.Labels = newLabels):

+	//

+	// newLabels, err := daemon.GetConflictFreeLabels(config.Labels)

+	// if err != nil {

+	//	return nil, err

+	// }

+	// config.Labels = newLabels

+	//

+	if _, err := daemon.GetConflictFreeLabels(config.Labels); err != nil {

+		logrus.Warnf("Engine labels with duplicate keys and conflicting values have been deprecated: %s", err)

+	}

+

 	// Regardless of whether the user sets it to true or false, if they

 	// specify TLSVerify at all then we need to turn on TLS

 	if config.IsValueSet(cliflags.FlagTLSVerify) {

@@ -220,6 +220,30 @@ func parseClusterAdvertiseSettings(clusterStore, clusterAdvertise string) (strin

 	return advertise, nil

 }

+// GetConflictFreeLabels validate Labels for conflict

+// In swarm the duplicates for labels are removed

+// so we only take same values here, no conflict values

+// If the key-value is the same we will only take the last label

+func GetConflictFreeLabels(labels []string) ([]string, error) {

+	labelMap := map[string]string{}

+	for _, label := range labels {

+		stringSlice := strings.SplitN(label, "=", 2)

+		if len(stringSlice) > 1 {

+			// If there is a conflict we will return an error

+			if v, ok := labelMap[stringSlice[0]]; ok && v != stringSlice[1] {

+				return nil, fmt.Errorf("conflict labels for %s=%s and %s=%s", stringSlice[0], stringSlice[1], stringSlice[0], v)

+			}

+			labelMap[stringSlice[0]] = stringSlice[1]

+		}

+	}

+

+	newLabels := []string{}

+	for k, v := range labelMap {

+		newLabels = append(newLabels, fmt.Sprintf("%s=%s", k, v))

+	}

+	return newLabels, nil

+}

+

 // ReloadConfiguration reads the configuration in the host and reloads the daemon and server.

 func ReloadConfiguration(configFile string, flags *pflag.FlagSet, reload func(*Config)) error {

 	logrus.Infof("Got signal to reload configuration, reloading from: %s", configFile)

@@ -232,6 +256,23 @@ func ReloadConfiguration(configFile string, flags *pflag.FlagSet, reload func(*C

 		return fmt.Errorf("file configuration validation failed (%v)", err)

 	}

+	// Labels of the docker engine used to allow multiple values associated with the same key.

+	// This is deprecated in 1.13, and, be removed after 3 release cycles.

+	// The following will check the conflict of labels, and report a warning for deprecation.

+	//

+	// TODO: After 3 release cycles (1.16) an error will be returned, and labels will be

+	// sanitized to consolidate duplicate key-value pairs (config.Labels = newLabels):

+	//

+	// newLabels, err := GetConflictFreeLabels(newConfig.Labels)

+	// if err != nil {

+	//      return err

+	// }

+	// newConfig.Labels = newLabels

+	//

+	if _, err := GetConflictFreeLabels(newConfig.Labels); err != nil {

+		logrus.Warnf("Engine labels with duplicate keys and conflicting values have been deprecated: %s", err)

+	}

+

 	reload(newConfig)

 	return nil

 }

@@ -26,6 +26,14 @@ see [Feature Deprecation Policy](index.md#feature-deprecation-policy).

 The daemon is moved to a separate binary (`dockerd`), and should be used instead.

+### Duplicate keys with conflicting values in engine labels

+**Deprecated In Release: [v1.13](https://github.com/docker/docker/releases/)**

+

+**Target For Removal In Release: v1.16**

+

+Duplicate keys with conflicting values have been deprecated. A warning is displayed

+in the output, and an error will be returned in the future.

+

 ### Three argument form in `docker import`

 **Deprecated In Release: [v0.6.7](https://github.com/docker/docker/releases/tag/v0.6.7)**

@@ -219,3 +219,15 @@ func (s *DockerDaemonSuite) TestRegistryMirrors(c *check.C) {

 	c.Assert(out, checker.Contains, fmt.Sprintf(" %s", registryMirror1))

 	c.Assert(out, checker.Contains, fmt.Sprintf(" %s", registryMirror2))

 }

+

+// Test case for #24392

+func (s *DockerDaemonSuite) TestInfoLabels(c *check.C) {

+	testRequires(c, SameHostDaemon, DaemonIsLinux)

+

+	err := s.d.Start("--label", `test.empty=`, "--label", `test.empty=`, "--label", `test.label="1"`, "--label", `test.label="2"`)

+	c.Assert(err, checker.IsNil)

+

+	out, err := s.d.Cmd("info")

+	c.Assert(err, checker.IsNil)

+	c.Assert(out, checker.Contains, "WARNING: labels with duplicate keys and conflicting values have been deprecated")

+}