add option for max connection

.gotty

@@ -54,6 +54,9 @@
 //       To enable reconnection, set `true` to `enable_reconnect`
 // reconnect_time = false
 
+// [int] Maximum connection to gotty, 0(default) means no limit.
+// max_connection = 0
+
 // [bool] Accept only one client and exit gotty once the client exits
 // once = false
 

app/app.go

@@ -28,6 +28,10 @@ import (
 	"github.com/yudai/umutex"
 )
 
+var (
+	connection int = 0
+)
+
 type InitMessage struct {
 	Arguments string `json:"Arguments,omitempty"`
 	AuthToken string `json:"AuthToken,omitempty"`
@@ -62,6 +66,7 @@ type Options struct {
 	TitleFormat         string                 `hcl:"title_format"`
 	EnableReconnect     bool                   `hcl:"enable_reconnect"`
 	ReconnectTime       int                    `hcl:"reconnect_time"`
+	MaxConnection       int                    `hcl:"max_connection"`
 	Once                bool                   `hcl:"once"`
 	PermitArguments     bool                   `hcl:"permit_arguments"`
 	CloseSignal         int                    `hcl:"close_signal"`
@@ -88,6 +93,7 @@ var DefaultOptions = Options{
 	TitleFormat:         "GoTTY - {{ .Command }} ({{ .Hostname }})",
 	EnableReconnect:     false,
 	ReconnectTime:       10,
+	MaxConnection:       0,
 	Once:                false,
 	CloseSignal:         1, // syscall.SIGHUP
 	Preferences:         HtermPrefernces{},
@@ -274,6 +280,12 @@ func (app *App) makeServer(addr string, handler *http.Handler) (*http.Server, er
 }
 
 func (app *App) handleWS(w http.ResponseWriter, r *http.Request) {
+	if app.options.MaxConnection != 0 {
+		if connection >= app.options.MaxConnection {
+			log.Printf("reached max connection: %d", app.options.MaxConnection)
+			return
+		}
+	}
 	log.Printf("New client connected: %s", r.RemoteAddr)
 
 	if r.Method != "GET" {
@@ -344,6 +356,9 @@ func (app *App) handleWS(w http.ResponseWriter, r *http.Request) {
 	}
 	log.Printf("Command is running for client %s with PID %d (args=%q)", r.RemoteAddr, cmd.Process.Pid, strings.Join(argv, " "))
 
+	connection++
+	log.Printf("Connection: %d/%d\n", connection, app.options.MaxConnection)
+
 	context := &clientContext{
 		app:        app,
 		request:    r,

app/client_context.go

@@ -79,7 +79,9 @@ func (context *clientContext) goHandleClient() {
 
 		context.command.Wait()
 		context.connection.Close()
+		connection--
 		log.Printf("Connection closed: %s", context.request.RemoteAddr)
+		log.Printf("Connection: %d/%d\n", connection, context.app.options.MaxConnection)
 	}()
 }
 

main.go

@@ -33,6 +33,7 @@ func main() {
 		flag{"title-format", "", "Title format of browser window"},
 		flag{"reconnect", "", "Enable reconnection"},
 		flag{"reconnect-time", "", "Time to reconnect"},
+		flag{"max-connection", "", "Maximum connection to gotty, 0(default) means no limit"},
 		flag{"once", "", "Accept only one client and exit on disconnection"},
 		flag{"permit-arguments", "", "Permit clients to send command line arguments in URL (e.g. http://example.com:8080/?arg=AAA&arg=BBB)"},
 		flag{"close-signal", "", "Signal sent to the command process when gotty close it (default: SIGHUP)"},