Container don't inherit from image labels

Labels are metadata that apply to a particular resource: image,
container, maybe volumes and networks in the future. We shouldn't have
containers inherit from its image labels: they are not the same obejcts,
and labels cannot be interpreted in the way.

It remains possible to apply metadata to an image using the LABEL
Dockerfile instruction, to query them using `docker inspect <img>`, or
to filter images on them using `docker images --filter <key>=<value>`.

Fixes #13770.

Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>

integration-cli/docker_cli_create_test.go

@@ -269,7 +269,7 @@ func (s *DockerSuite) TestCreateLabelFromImage(c *check.C) {
 	}
 
 	name := "test_create_labels_from_image"
-	expected := map[string]string{"k2": "x", "k3": "v3", "k1": "v1"}
+	expected := map[string]string{"k2": "x", "k3": "v3"}
 	if out, _, err := runCommandWithOutput(exec.Command(dockerBinary, "create", "--name", name, "-l", "k2=x", "--label", "k3=v3", imageName)); err != nil {
 		c.Fatal(out, err)
 	}

runconfig/merge.go

@@ -41,16 +41,6 @@ func Merge(userConf, imageConf *Config) error {
 		}
 	}
 
-	if userConf.Labels == nil {
-		userConf.Labels = map[string]string{}
-	}
-	if imageConf.Labels != nil {
-		for l := range userConf.Labels {
-			imageConf.Labels[l] = userConf.Labels[l]
-		}
-		userConf.Labels = imageConf.Labels
-	}
-
 	if userConf.Entrypoint.Len() == 0 {
 		if userConf.Cmd.Len() == 0 {
 			userConf.Cmd = imageConf.Cmd