closes getlantern/lantern#2288 Added headless mode for lantern

run.bash

@@ -2,5 +2,5 @@
 
 source setenv.bash
 pushd src/github.com/getlantern/flashlight
-go build && ./flashlight
+go build && ./flashlight "$@"
 popd

src/github.com/getlantern/flashlight/README.md

@@ -36,18 +36,20 @@ Usage of flashlight:
   -configdir="": directory in which to store configuration, including flashlight.yaml (defaults to current directory)
   -country="xx": 2 digit country code under which to report stats. Defaults to xx.
   -cpuprofile="": write cpu profile to given file
+  -headless=false: if true, lantern will run with no ui
   -help=false: Get usage help
+  -httptest.serve="": if non-empty, httptest.NewServer serves on this address and blocks
   -instanceid="": instanceId under which to report stats to statshub. If not specified, no stats are reported.
   -memprofile="": write heap profile to given file
   -parentpid=0: the parent process's PID, used on Windows for killing flashlight when the parent disappears
   -portmap=0: try to map this port on the firewall to the port on which flashlight is listening, using UPnP or NAT-PMP. If mapping this port fails, flashlight will exit with status code 50
+  -registerat="": base URL for peer DNS registry at which to register (e.g. https://peerscanner.getiantem.org)
   -role="": either 'client' or 'server' (required)
   -server="": FQDN of flashlight server when running in server mode (required)
-  -statsaddr="": host:port at which to make detailed stats available using server-sent events (optional)
   -statshub="pure-journey-3547.herokuapp.com": address of statshub server
-  -statsperiod=0: time in seconds to wait between reporting stats. If not specified, stats are not reported. If specified, statshub, instanceid and statsaddr must also be specified.
-  -waddelladdr="": if specified, connect to this waddell server and process NAT traversal requests inbound from waddell
-  -waddellcert="": if specified, use this cert (PEM-encoded) to authenticate connections to waddell.  Otherwise, a default certificate is used.
+  -statsperiod=0: time in seconds to wait between reporting stats. If not specified, stats are not reported. If specified, statshub, instanceid and statshubAddr must also be specified.
+  -uiaddr="": if specified, indicates host:port the UI HTTP server should be started on
+  -unencrypted=false: set to true to run server in unencrypted mode (no TLS)
 ```
 
 Example Client:

src/github.com/getlantern/flashlight/flashlight.go

@@ -35,9 +35,12 @@ var (
 	// Command-line Flags
 	help      = flag.Bool("help", false, "Get usage help")
 	parentPID = flag.Int("parentpid", 0, "the parent process's PID, used on Windows for killing flashlight when the parent disappears")
+	headless  = flag.Bool("headless", false, "if true, lantern will run with no ui")
 
 	configUpdates = make(chan *config.Config)
 	exitCh        = make(chan error, 1)
+
+	showui = true
 )
 
 func init() {
@@ -52,7 +55,15 @@ func init() {
 }
 
 func main() {
-	systray.Run(_main)
+	flag.Parse()
+	showui = !*headless
+
+	if showui {
+		systray.Run(_main)
+	} else {
+		log.Debug("Running headless")
+		_main()
+	}
 }
 
 func _main() {
@@ -76,13 +87,14 @@ func doMain() error {
 	defer systray.Quit()
 
 	i18nInit()
-	err = configureSystemTray()
-	if err != nil {
-		return err
+	if showui {
+		err = configureSystemTray()
+		if err != nil {
+			return err
+		}
 	}
 	displayVersion()
 
-	flag.Parse()
 	configUpdates = make(chan *config.Config)
 	cfg, err := config.Init()
 	if err != nil {
@@ -154,7 +166,9 @@ func runClientProxy(cfg *config.Config) {
 			exit(fmt.Errorf("Unable to start UI: %v", err))
 			return
 		}
-		ui.Show()
+		if showui {
+			ui.Show()
+		}
 	}
 
 	logging.Configure(cfg, version, buildDate)