refactor remote browser launching

resolve #408

lib/docker/Dockerfile

@@ -1,20 +1,17 @@
-# Examples:
+# To build the image:
 #
-#   docker build -t ghcr.io/go-rod/rod -f lib/docker/Dockerfile .
+#     docker build -t ghcr.io/go-rod/rod -f lib/docker/Dockerfile .
 #
-#   // use mirrors
-#   docker build --build-arg goproxy=https://goproxy.io,direct --build-arg apt_sources=https://mirrors.tuna.tsinghua.edu.cn \
-#     -t ghcr.io/go-rod/rod -f lib/docker/Dockerfile .
 
-# build rod-launcher tool
+# build rod-manager
 FROM golang AS go
 
-ARG goproxy=""
+ARG goproxy="https://goproxy.io,direct"
 
 COPY . /rod
 WORKDIR /rod
 RUN go env -w GO111MODULE=on && go env -w GOPROXY=$goproxy
-RUN go build ./lib/launcher/rod-launcher
+RUN go build ./lib/launcher/rod-manager
 RUN go run ./lib/utils/get-browser
 
 FROM ubuntu:bionic
@@ -49,6 +46,6 @@ RUN sed -i "s|http://archive.ubuntu.com|$apt_sources|g" /etc/apt/sources.list &&
 ENTRYPOINT ["dumb-init", "--"]
 
 COPY --from=go /root/.cache/rod /root/.cache/rod
-COPY --from=go /rod/rod-launcher /usr/bin/
+COPY --from=go /rod/rod-manager /usr/bin/
 
-CMD rod-launcher
+CMD rod-manager

lib/examples/launch-managed/main.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/go-rod/rod"
+	"github.com/go-rod/rod/lib/launcher"
+	"github.com/go-rod/rod/lib/utils"
+)
+
+func main() {
+	// This example is to launch a browser remotely, not connect to a running browser remotely,
+	// to connect to a running browser check the "../connect-browser" example.
+	// Rod provides a docker image for beginers, run the below to start a launcher.Manager:
+	//
+	//     docker run -p 7317:7317 ghcr.io/go-rod/rod
+	//
+	// For more information, check the doc of launcher.Manager
+	l := launcher.MustNewManaged("")
+
+	// You can also set any flag remotely before you launch the remote browser.
+	// Available flags: https://peter.sh/experiments/chromium-command-line-switches
+	l.Set("disable-gpu").Delete("disable-gpu")
+
+	// Launch with headful mode
+	l.Headless(false).XVFB("--server-num=5", "--server-args=-screen 0 1600x900x16")
+
+	browser := rod.New().Client(l.Client()).MustConnect()
+
+	// You may want to start a server to watch the screenshots of the remote browser.
+	launcher.Open(browser.ServeMonitor(""))
+
+	fmt.Println(
+		browser.MustPage("https://example.com/").MustEval("() => document.title"),
+	)
+
+	utils.Pause()
+}

lib/launcher/launcher.go

@@ -21,22 +21,26 @@ const (
 	flagWorkingDir = "rod-working-dir"
 	flagEnv        = "rod-env"
 	flagXVFB       = "rod-xvfb"
+	flagLeakless   = "rod-leakless"
+	flagBin        = "rod-bin"
 )
 
 // Launcher is a helper to launch browser binary smartly
 type Launcher struct {
-	logger    io.Writer
+	Flags map[string][]string `json:"flags"`
+
 	ctx       context.Context
 	ctxCancel func()
-	browser   *Browser
-	bin       string
-	url       string
-	parser    *URLParser
-	Flags     map[string][]string `json:"flags"`
-	pid       int
-	exit      chan struct{}
-	remote    bool // remote mode or not
-	leakless  bool
+
+	logger io.Writer
+
+	browser *Browser
+	parser  *URLParser
+	pid     int
+	exit    chan struct{}
+
+	managed    bool
+	serviceURL string
 }
 
 // New returns the default arguments to start browser.
@@ -50,6 +54,9 @@ func New() *Launcher {
 	}
 
 	defaultFlags := map[string][]string{
+		flagBin:      {defaults.Bin},
+		flagLeakless: nil,
+
 		"user-data-dir": {dir},
 
 		// use random port by default
@@ -109,9 +116,7 @@ func New() *Launcher {
 		Flags:     defaultFlags,
 		exit:      make(chan struct{}),
 		browser:   NewBrowser(),
-		bin:       defaults.Bin,
 		parser:    NewURLParser(),
-		leakless:  true,
 		logger:    ioutil.Discard,
 	}
 }
@@ -129,10 +134,10 @@ func NewUserMode() *Launcher {
 		Flags: map[string][]string{
 			"remote-debugging-port": {"37712"},
 			"no-startup-window":     nil,
+			flagBin:                 {bin},
 		},
 		browser: NewBrowser(),
 		exit:    make(chan struct{}),
-		bin:     bin,
 		parser:  NewURLParser(),
 		logger:  ioutil.Discard,
 	}
@@ -159,6 +164,12 @@ func (l *Launcher) Get(name string) (string, bool) {
 	return "", false
 }
 
+// Has flag or not
+func (l *Launcher) Has(name string) bool {
+	_, has := l.GetFlags(name)
+	return has
+}
+
 // GetFlags from settings
 func (l *Launcher) GetFlags(name string) ([]string, bool) {
 	flag, has := l.Flags[l.normalizeFlag(name)]
@@ -189,8 +200,7 @@ func (l *Launcher) Delete(name string) *Launcher {
 
 // Bin set browser executable file path. If it's empty, launcher will automatically search or download the bin.
 func (l *Launcher) Bin(path string) *Launcher {
-	l.bin = path
-	return l
+	return l.Set(flagBin, path)
 }
 
 // Headless switch. Whether to run browser in headless mode. A mode without visible UI.
@@ -220,8 +230,10 @@ func (l *Launcher) XVFB(args ...string) *Launcher {
 // Leakless switch. If enabled, the browser will be force killed after the Go process exits.
 // The doc of leakless: https://github.com/ysmood/leakless.
 func (l *Launcher) Leakless(enable bool) *Launcher {
-	l.leakless = enable
-	return l
+	if enable {
+		return l.Set(flagLeakless)
+	}
+	return l.Delete(flagLeakless)
 }
 
 // Devtools switch to auto open devtools for each tab
@@ -257,12 +269,8 @@ func (l *Launcher) ProfileDir(dir string) *Launcher {
 }
 
 // RemoteDebuggingPort to launch the browser. Zero for a random port. Zero is the default value.
-// If it's not zero, the launcher will try to connect to it before starting a new browser process.
-// For example, to reuse the same browser process for between 2 runs of a Go program, you can
-// do something like:
-//     launcher.New().RemoteDebuggingPort(9222).MustLaunch()
-//
-// Related doc: https://chromedevtools.github.io/devtools-protocol/
+// If it's not zero and the Launcher.Leakless is disabled, the launcher will try to reconnect to it first,
+// if the reconnection fails it will launch a new browser.
 func (l *Launcher) RemoteDebuggingPort(port int) *Launcher {
 	return l.Set("remote-debugging-port", fmt.Sprintf("%d", port))
 }
@@ -345,7 +353,7 @@ func (l *Launcher) Launch() (string, error) {
 	var ll *leakless.Launcher
 	var cmd *exec.Cmd
 
-	if l.leakless && leakless.Support() {
+	if l.Has(flagLeakless) && leakless.Support() {
 		ll = leakless.New()
 		cmd = ll.Command(bin, l.FormatArgs()...)
 	} else {
@@ -400,11 +408,12 @@ func (l *Launcher) setupCmd(cmd *exec.Cmd) {
 }
 
 func (l *Launcher) getBin() (string, error) {
-	if l.bin == "" {
+	bin, _ := l.Get(flagBin)
+	if bin == "" {
 		l.browser.Context = l.ctx
 		return l.browser.Get()
 	}
-	return l.bin, nil
+	return bin, nil
 }
 
 func (l *Launcher) getURL() (u string, err error) {

lib/launcher/launcher_test.go

@@ -103,13 +103,13 @@ func (t T) Launch() {
 	}
 
 	{
-		_, err := launcher.NewRemote("")
+		_, err := launcher.NewManaged("")
 		t.Err(err)
 
-		_, err = launcher.NewRemote("1://")
+		_, err = launcher.NewManaged("1://")
 		t.Err(err)
 
-		_, err = launcher.NewRemote("ws://not-exists")
+		_, err = launcher.NewManaged("ws://not-exists")
 		t.Err(err)
 	}
 }

lib/launcher/load_test.go

@@ -12,7 +12,7 @@ import (
 	"github.com/ysmood/got"
 )
 
-func BenchmarkRemoteLauncher(b *testing.B) {
+func BenchmarkManager(b *testing.B) {
 	const concurrent = 30 // how many browsers will run at the same time
 	const num = 300       // how many browsers we will launch
 
@@ -47,7 +47,7 @@ func BenchmarkRemoteLauncher(b *testing.B) {
 				}()
 			}()
 
-			l := launcher.MustNewRemote("")
+			l := launcher.MustNewManaged("")
 			client := l.Client()
 			browser := rod.New().Context(ctx).Client(client).MustConnect()
 			page := browser.MustPage()