thanks in advance for any help or advice!
I am building a chess application, the frontend is in Reactjs and backend is a server written in Golang using Gorilla mux library. The backend is a chess engine for the human user to play against. The react frontend creates a WebSocket connection with the server in the top-level constructor.
The app works well for a single connection. However, upon opening a second browser tab, the first browser tab's Websocket connection is lost.
The server reports the error,
read error: websocket: close 1001 (going away)
and then,
read error: read tcp 127.0.0.1:8081-\u003e127.0.0.1:64146: use of closed network connection
I've looked at the Gorrilla/mux documentation for websockets and am reading/writing all from the same function in order to avoid concurrent reads or writes on the same connection.
React frontend constructor is here:
class Game extends React.Component {
constructor(props) {
super(props);
this.state = {
history: [{
position: this.props.chess.fen(),
move: "",
}],
ply: 0,
selectedSq: null,
engineName: "",
engineAuthor: "",
uciOK: false,
isReady: false,
engineThinking: false,
playersTurn: true,
playerColor: WHITE,
};
this.ws = websocketConnect("ws://localhost:8081/uci");
this.ws.onmessage = (event) => {
const msg = event.data
this.processEngineMessage(msg)
}
}
It is referencing websocket.js which is here:
export function websocketConnect(url) {
const ws = new WebSocket(url);
ws.addEventListener('open', (event) => {
ws.send('uci');
});
return ws;
}
Goland Websocket package is here
package websocket
import (
"net/http"
"github.com/namsral/flag"
log "github.com/sirupsen/logrus"
"github.com/gorilla/websocket"
)
type WebsocketServer struct {
upgrader websocket.Upgrader
addr *string
conn *websocket.Conn
}
func NewWebsocketServer() *WebsocketServer {
w := new(WebsocketServer)
w.addr = flag.String("addr", "localhost:8081", "http service address")
flag.Parse()
w.upgrader = websocket.Upgrader{} // use default options
http.HandleFunc("/uci", w.uciHandler)
return w
}
func (w *WebsocketServer) uciHandler(rw http.ResponseWriter, r *http.Request) {
var err error
log.Error("upgrading to websocket connection")
w.upgrader.CheckOrigin = func(r *http.Request) bool { return true }
w.conn, err = w.upgrader.Upgrade(rw, r, nil)
if err != nil {
log.Print("upgrade:", err)
return
}
go w.UCI(rw, r)
}
func (w *WebsocketServer) Start() {
log.Info("starting websocket server")
http.ListenAndServe(*w.addr, nil)
}
func (w *WebsocketServer) CloseConnection() {
w.conn.Close()
}
func (w *WebsocketServer) StartReader(channel chan string) {
for {
_, message, err := w.conn.ReadMessage()
if err != nil {
log.Println("read error:", err)
break
}
log.Printf("recv: %s", message)
channel <- string(message)
}
}
func (w *WebsocketServer) Write(msg string) {
err := w.conn.WriteMessage(websocket.TextMessage, []byte(msg))
if err != nil {
log.Println("write:", err)
}
}
Full code here: server: https://github.com/tonyOreglia/glee frontend: https://github.com/tonyOreglia/chess-board-react
I am hoping to be able to support multiple concurrent users using the website. It is currently hosted on DigitalOcean.
