Change content-type for json stream to application/x-json-stream.

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Upstream-commit: 10ab2089ce189d5bea3f7aaac3b5081471309478
Component: engine

components/engine/api/server/server.go

@@ -102,6 +102,10 @@ func writeJSON(w http.ResponseWriter, code int, v engine.Env) error {
 
 func streamJSON(job *engine.Job, w http.ResponseWriter, flush bool) {
 	w.Header().Set("Content-Type", "application/json")
+	if job.GetenvBool("lineDelim") {
+		w.Header().Set("Content-Type", "application/x-json-stream")
+	}
+
 	if flush {
 		job.Stdout.Add(utils.NewWriteFlusher(w))
 	} else {
@@ -976,6 +980,7 @@ func postBuild(eng *engine.Engine, version version.Version, w http.ResponseWrite
 	job.Setenv("q", r.FormValue("q"))
 	job.Setenv("nocache", r.FormValue("nocache"))
 	job.Setenv("forcerm", r.FormValue("forcerm"))
+	job.SetenvBool("lineDelim", version.GreaterThanOrEqualTo("1.15"))
 	job.SetenvJson("authConfig", authConfig)
 	job.SetenvJson("configFile", configFile)
 

components/engine/api/server/server_unit_test.go

@@ -275,7 +275,7 @@ func TestGetEvents(t *testing.T) {
 	if !called {
 		t.Fatal("handler was not called")
 	}
-	assertContentType(r, "application/json", t)
+	assertContentType(r, "application/x-json-stream", t)
 	var stdout_json struct {
 		Since int
 		Until int