fix: Retry RTC connection attempts multiple times

Author: kylecarbs

wsnet/listen.go

@@ -18,7 +18,7 @@ import (
 	"cdr.dev/coder-cli/coder-sdk"
 )
 
-var keepAliveInterval = 5 * time.Second
+var connectionRetryInterval = time.Second
 
 // Listen connects to the broker proxies connections to the local net.
 // Close will end all RTC connections.
@@ -41,8 +41,19 @@ func Listen(ctx context.Context, broker string) (io.Closer, error) {
 				// If we hit an EOF, then the connection to the broker
 				// was interrupted. We'll take a short break then dial
 				// again.
-				time.Sleep(time.Second)
-				ch, err = l.dial(ctx)
+				ticker := time.NewTicker(connectionRetryInterval)
+				for {
+					select {
+					case <-ticker.C:
+						ch, err = l.dial(ctx)
+					case <-ctx.Done():
+						err = ctx.Err()
+					}
+					if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+						break
+					}
+				}
+				ticker.Stop()
 			}
 			if err != nil {
 				l.acceptError = err
@@ -79,7 +90,6 @@ func (l *listener) dial(ctx context.Context) (<-chan error, error) {
 	l.ws = conn
 	nconn := websocket.NetConn(ctx, conn, websocket.MessageBinary)
 	config := yamux.DefaultConfig()
-	config.KeepAliveInterval = keepAliveInterval
 	config.LogOutput = io.Discard
 	session, err := yamux.Server(nconn, config)
 	if err != nil {

wsnet/listen_test.go

@@ -13,22 +13,22 @@ import (
 
 func TestListen(t *testing.T) {
 	t.Run("Reconnect", func(t *testing.T) {
-		keepAliveInterval = 50 * time.Millisecond
+		connectionRetryInterval = 10 * time.Millisecond
 
 		var (
-			connCh = make(chan interface{})
+			connCh = make(chan *websocket.Conn)
 			mux    = http.NewServeMux()
 			srv    = http.Server{
 				Handler: mux,
 			}
 		)
 		mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-			_, err := websocket.Accept(w, r, nil)
+			ws, err := websocket.Accept(w, r, nil)
 			if err != nil {
 				t.Error(err)
 				return
 			}
-			connCh <- struct{}{}
+			connCh <- ws
 		})
 
 		listener, err := net.Listen("tcp4", "127.0.0.1:0")
@@ -47,8 +47,15 @@ func TestListen(t *testing.T) {
 			t.Error(err)
 			return
 		}
-		<-connCh
+		conn := <-connCh
 		_ = listener.Close()
+		// We need to close the connection too... closing a TCP
+		// listener does not close active local connections.
+		_ = conn.Close(websocket.StatusGoingAway, "")
+
+		// At least a few retry attempts should be had...
+		time.Sleep(connectionRetryInterval * 5)
+
 		listener, err = net.Listen("tcp4", addr.String())
 		if err != nil {
 			t.Error(err)