Do you can concurently launch several chrome instances each with own user-data-dir

[MikhailKlemin]

What I want is to have several instances running each with it's own datadir:
Say create concurrently several of this with different profiles?

I guess I cannot? Because new instance will mess up with already launched?

func create(profile string) *rod.Browser {
	l := launcher.NewUserMode().UserDataDir(profile).
		Headless(false).
		Set("blink-settings", "imagesEnabled=false").
		Devtools(false)

	url := l.MustLaunch()
	//l.Cleanup()

	browser := rod.New().
		ControlURL(url).
		Trace(false).
		SlowMotion(1 * time.Second).
		MustConnect()

	return browser

}

[ysmood]

Yes, you can. Check the unit test of Rod itself, it will run each test concurrently with multiple browsers.

rod/setup_test.go

Line 60 in 0998fcc

parallel := got.Parallel()

[MikhailKlemin]

If I just use standard launcher (I mean without NewUserMode -- it's all works fine):

// this will work fine:
func create(profile string) *rod.Browser {
	//l := launcher.NewUserMode().UserDataDir(profile).
	path, _ := launcher.LookPath()
	l := launcher.New().Bin(path).
		Headless(false).
		Set("blink-settings", "imagesEnabled=false").
		Devtools(false)

	url := l.MustLaunch()
	browser := rod.New().
		ControlURL(url).
		Trace(false).
		SlowMotion(1 * time.Second).
		MustConnect()

	return browser
}

But code bellow with parallel produces unpredictable (at my glance) behavior:

func create(profile string) *rod.Browser {
	l := launcher.NewUserMode().UserDataDir(profile).
		Headless(false).
		Set("blink-settings", "imagesEnabled=false").
		Devtools(false)

	url := l.MustLaunch()

	browser := rod.New().
		ControlURL(url).
		Trace(false).
		SlowMotion(1 * time.Second).
		MustConnect()

	return browser

}

func main() {
	sem := make(chan bool, 5)
	for i := 0; i < 5; i++ {
		sem <- true
		go func(i int) {
			defer func() { <-sem }()
			b := create(fmt.Sprintf("/tmp/%d", i))
			_, err := b.Page(proto.TargetCreateTarget{})
			if err != nil {
				log.Fatal(err)
			}
			time.Sleep(5 * time.Second)
			fmt.Printf("Closing browser # %d\n", i)
			err = b.Close()
			if err != nil {
				log.Fatal(err)
			}

		}(i)
	}

	for i := 0; i < cap(sem); i++ {
		sem <- true
	}

}

Some of issues might be caused, by pop window Chrome launches asking to make it Default Browser.

[ysmood]

Yes, using user-mode is crazy, I will never do that, chromium is not designed to do that, unexpected behavior is not surprising for me.

[MikhailKlemin]

Maybe I do not understand something obvious, I only need to have several instances running in parallel with separate UserDataDirs.

[ysmood]

Why not use launcher.New()?

[MikhailKlemin]

I want to check same website in parallel with different sets of data stored in cookies, web storage and other persistent options if they are exists.
I thought that getting each chrome instance with it's own profile would solve that.

[ysmood]

func create(profile string) *rod.Browser {
	u := launcher.New().UserDataDir(profile).
		Set("blink-settings", "imagesEnabled=false").
		MustLaunch()

	return rod.New().ControlURL(u).MustConnect()
}

func main() {
	wg := sync.WaitGroup{}
	for range "....." {
		wg.Add(1)
		go func() {
			defer wg.Done()

			p := filepath.Join(os.TempDir(), utils.RandString(8))

			b := create(p)
			b.MustPage()
			fmt.Println("Browser started:", p)
			time.Sleep(5 * time.Second)
			b.MustClose()
			fmt.Println("Browser stopped:", p)
		}()
	}
	wg.Wait()
}

[MikhailKlemin]

This works fine, thanks a lot!
I have tried almost the same but was getting panic error panic: [launcher] Failed to get the debug url: Opening in existing browser session. and then I started looking I guess into wrong direction!