Use mime types to parse Content-Type

api.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"io/ioutil"
 	"log"
+	"mime"
 	"net"
 	"net/http"
 	"os"
@@ -81,6 +82,14 @@ func getBoolParam(value string) (bool, error) {
 	return ret, nil
 }
 
+func matchesContentType(contentType, expectedType string) bool {
+	mimetype, _, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		utils.Debugf("Error parsing media type: %s error: %s", contentType, err.Error())
+	}
+	return err == nil && mimetype == expectedType
+}
+
 func postAuth(srv *Server, version float64, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
 	authConfig := &auth.AuthConfig{}
 	err := json.NewDecoder(r.Body).Decode(authConfig)
@@ -594,7 +603,7 @@ func postContainersStart(srv *Server, version float64, w http.ResponseWriter, r
 
 	// allow a nil body for backwards compatibility
 	if r.Body != nil {
-		if r.Header.Get("Content-Type") == "application/json" {
+		if matchesContentType(r.Header.Get("Content-Type"), "application/json") {
 			if err := json.NewDecoder(r.Body).Decode(hostConfig); err != nil {
 				return err
 			}

api_test.go

@@ -1142,6 +1142,20 @@ func TestDeleteImages(t *testing.T) {
 		} */
 }
 
+func TestJsonContentType(t *testing.T) {
+	if !matchesContentType("application/json", "application/json") {
+		t.Fail()
+	}
+
+	if !matchesContentType("application/json; charset=utf-8", "application/json") {
+		t.Fail()
+	}
+
+	if matchesContentType("dockerapplication/json", "application/json") {
+		t.Fail()
+	}
+}
+
 // Mocked types for tests
 type NopConn struct {
 	io.ReadCloser

commands.go

@@ -1567,7 +1567,7 @@ func (cli *DockerCli) stream(method, path string, in io.Reader, out io.Writer) e
 		return fmt.Errorf("Error: %s", body)
 	}
 
-	if resp.Header.Get("Content-Type") == "application/json" {
+	if matchesContentType(resp.Header.Get("Content-Type"), "application/json") {
 		return utils.DisplayJSONMessagesStream(resp.Body, out)
 	} else {
 		if _, err := io.Copy(out, resp.Body); err != nil {