Merge pull request #316 from cpuguy83/race_on_output_start_error

Fix for race from error on process start

libcontainer/integration/execin_test.go

@@ -133,16 +133,23 @@ func TestExecInError(t *testing.T) {
 	}()
 	ok(t, err)
 
-	unexistent := &libcontainer.Process{
-		Args: []string{"unexistent"},
-		Env:  standardEnvironment,
-	}
-	err = container.Start(unexistent)
-	if err == nil {
-		t.Fatal("Should be an error")
-	}
-	if !strings.Contains(err.Error(), "executable file not found") {
-		t.Fatalf("Should be error about not found executable, got %s", err)
+	for i := 0; i < 42; i++ {
+		var out bytes.Buffer
+		unexistent := &libcontainer.Process{
+			Args:   []string{"unexistent"},
+			Env:    standardEnvironment,
+			Stdout: &out,
+		}
+		err = container.Start(unexistent)
+		if err == nil {
+			t.Fatal("Should be an error")
+		}
+		if !strings.Contains(err.Error(), "executable file not found") {
+			t.Fatalf("Should be error about not found executable, got %s", err)
+		}
+		if !bytes.Contains(out.Bytes(), []byte("executable file not found")) {
+			t.Fatalf("executable file not found error not delivered to stdio:\n%s", out.String())
+		}
 	}
 }
 

libcontainer/process_linux.go

@@ -84,6 +84,7 @@ func (p *setnsProcess) start() (err error) {
 		return newSystemError(err)
 	}
 	if ierr != nil {
+		p.wait()
 		return newSystemError(ierr)
 	}