agent/proxy: make the logs test a bit more robust by waiting for file

agent/proxy/manager_test.go

@@ -203,7 +203,8 @@ func TestManagerRun_daemonLogs(t *testing.T) {
 	m.LogDir = filepath.Join(td, "logs")
 
 	// Create the service and calculate the log paths
-	id := testStateProxy(t, state, "web", helperProcess("output"))
+	path := filepath.Join(td, "notify")
+	id := testStateProxy(t, state, "web", helperProcess("output", path))
 	stdoutPath := logPath(m.LogDir, id, "stdout")
 	stderrPath := logPath(m.LogDir, id, "stderr")
 
@@ -212,13 +213,9 @@ func TestManagerRun_daemonLogs(t *testing.T) {
 
 	// We should see the path appear shortly
 	retry.Run(t, func(r *retry.R) {
-		if _, err := os.Stat(stdoutPath); err != nil {
+		if _, err := os.Stat(path); err != nil {
 			r.Fatalf("error waiting for stdout path: %s", err)
 		}
-
-		if _, err := os.Stat(stderrPath); err != nil {
-			r.Fatalf("error waiting for stderr path: %s", err)
-		}
 	})
 
 	expectedOut := "hello stdout\n"

agent/proxy/proxy_test.go

@@ -141,6 +141,18 @@ func TestHelperProcess(t *testing.T) {
 	case "output":
 		fmt.Fprintf(os.Stdout, "hello stdout\n")
 		fmt.Fprintf(os.Stderr, "hello stderr\n")
+
+		// Sync to be sure it is written out of buffers
+		os.Stdout.Sync()
+		os.Stderr.Sync()
+
+		// Output a file to signal we've written to stdout/err
+		path := args[0]
+		if err := ioutil.WriteFile(path, []byte("hello"), 0644); err != nil {
+			fmt.Fprintf(os.Stderr, "Error: %s\n", err)
+			os.Exit(1)
+		}
+
 		<-make(chan struct{})
 
 	default: