Open Web UI in Browser Automatically

deps.bzl

@@ -3636,3 +3636,9 @@ def prysm_deps():
         sum = "h1:W0LEBv82YCGEtcmPA3uNZBI33/qF//HAAs3MawDjRa0=",
         version = "v0.0.0-20160331181800-b5bfa59ec0ad",
     )
+    go_repository(
+        name = "com_github_google_shlex",
+        importpath = "github.com/google/shlex",
+        sum = "h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=",
+        version = "v0.0.0-20191202100458-e7afc7fbc510",
+    )

go.mod

@@ -34,6 +34,7 @@ require (
 	github.com/golang/protobuf v1.4.2
 	github.com/golang/snappy v0.0.2-0.20200707131729-196ae77b8a26
 	github.com/google/gofuzz v1.1.1-0.20200604201612-c04b05f3adfa
+	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
 	github.com/google/uuid v1.1.1
 	github.com/gorilla/websocket v1.4.2
 	github.com/graph-gophers/graphql-go v0.0.0-20200309224638-dae41bde9ef9 // indirect

go.sum

@@ -345,6 +345,8 @@ github.com/google/pprof v0.0.0-20181206194817-3ea8567a2e57/go.mod h1:zfwlbNMJ+OI
 github.com/google/pprof v0.0.0-20190515194954-54271f7e092f/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
 github.com/google/pprof v0.0.0-20191218002539-d4f498aebedc/go.mod h1:ZgVRPoUq/hfqzAqh7sHMqb3I9Rq5C59dIz2SbBwJ4eM=
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
+github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
 github.com/google/uuid v1.0.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

shared/browser/BUILD.bazel

@@ -0,0 +1,16 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_test")
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["browser.go"],
+    importpath = "github.com/prysmaticlabs/prysm/shared/browser",
+    visibility = ["//visibility:public"],
+    deps = ["@com_github_google_shlex//:go_default_library"],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["browser_test.go"],
+    embed = [":go_default_library"],
+)

shared/browser/browser.go

@@ -0,0 +1,57 @@
+/**
+Package from the official Github CLI https://github.com/cli/cli/blob/f30bc5bc64f9c3a839e39713adab48790264119c/pkg/browser/browser.go
+All rights reserved to the package authors, respectively. MIT License. See https://github.com/cli/cli/blob/trunk/LICENSE
+*/
+package browser
+
+import (
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"github.com/google/shlex"
+)
+
+// Command produces an exec.Cmd respecting runtime.GOOS and $BROWSER environment variable
+func Command(url string) (*exec.Cmd, error) {
+	launcher := os.Getenv("BROWSER")
+	if launcher != "" {
+		return FromLauncher(launcher, url)
+	}
+	return ForOS(runtime.GOOS, url), nil
+}
+
+// ForOS produces an exec.Cmd to open the web browser for different OS
+func ForOS(goos, url string) *exec.Cmd {
+	exe := "open"
+	var args []string
+	switch goos {
+	case "darwin":
+		args = append(args, url)
+	case "windows":
+		exe = "cmd"
+		r := strings.NewReplacer("&", "^&")
+		args = append(args, "/c", "start", r.Replace(url))
+	default:
+		exe = "xdg-open"
+		args = append(args, url)
+	}
+
+	cmd := exec.Command(exe, args...)
+	cmd.Stderr = os.Stderr
+	return cmd
+}
+
+// FromLauncher parses the launcher string based on shell splitting rules
+func FromLauncher(launcher, url string) (*exec.Cmd, error) {
+	args, err := shlex.Split(launcher)
+	if err != nil {
+		return nil, err
+	}
+
+	args = append(args, url)
+	cmd := exec.Command(args[0], args[1:]...)
+	cmd.Stderr = os.Stderr
+	return cmd, nil
+}

shared/browser/browser_test.go

@@ -0,0 +1,54 @@
+/**
+Package from the official Github CLI https://github.com/cli/cli/blob/f30bc5bc64f9c3a839e39713adab48790264119c/pkg/browser/browser.go
+All rights reserved to the package authors, respectively. MIT License. See https://github.com/cli/cli/blob/trunk/LICENSE
+*/
+package browser
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestForOS(t *testing.T) {
+	type args struct {
+		goos string
+		url  string
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			name: "macOS",
+			args: args{
+				goos: "darwin",
+				url:  "https://example.com/path?a=1&b=2",
+			},
+			want: []string{"open", "https://example.com/path?a=1&b=2"},
+		},
+		{
+			name: "Linux",
+			args: args{
+				goos: "linux",
+				url:  "https://example.com/path?a=1&b=2",
+			},
+			want: []string{"xdg-open", "https://example.com/path?a=1&b=2"},
+		},
+		{
+			name: "Windows",
+			args: args{
+				goos: "windows",
+				url:  "https://example.com/path?a=1&b=2&c=3",
+			},
+			want: []string{"cmd", "/c", "start", "https://example.com/path?a=1^&b=2^&c=3"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if cmd := ForOS(tt.args.goos, tt.args.url); !reflect.DeepEqual(cmd.Args, tt.want) {
+				t.Errorf("ForOS() = %v, want %v", cmd.Args, tt.want)
+			}
+		})
+	}
+}

validator/web/BUILD.bazel

@@ -15,6 +15,7 @@ go_library(
     visibility = ["//validator:__subpackages__"],
     deps = [
         "//shared:go_default_library",
+        "//shared/browser:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
 )

validator/web/handler.go

@@ -5,8 +5,6 @@ import (
 	"net/http"
 	"net/url"
 	"path"
-
-	log "github.com/sirupsen/logrus"
 )
 
 const prefix = "external/prysm_web_ui"

validator/web/server.go

@@ -6,10 +6,14 @@ import (
 	"time"
 
 	"github.com/prysmaticlabs/prysm/shared"
-	log "github.com/sirupsen/logrus"
+	"github.com/prysmaticlabs/prysm/shared/browser"
+	"github.com/sirupsen/logrus"
 )
 
-var _ = shared.Service(&Server{})
+var (
+	_   = shared.Service(&Server{})
+	log = logrus.WithField("prefix", "prysm-web")
+)
 
 // Server for the Prysm Web UI.
 type Server struct {
@@ -37,6 +41,16 @@ func (s *Server) Start() {
 			log.WithError(err).Error("Failed to start validator web server")
 		}
 	}()
+	time.Sleep(time.Second * 1)
+	cmd, err := browser.Command("http://" + s.http.Addr)
+	if err != nil {
+		log.WithError(err).Errorf("Could not open Prysm web UI in browser")
+		return
+	}
+	if err := cmd.Run(); err != nil {
+		log.WithError(err).Errorf("Could not open Prysm web UI in browser")
+		return
+	}
 }
 
 // Stop the web server gracefully with 1s timeout.