add CLI options for WebSockets support

src/wormhole_transit_relay/server_tap.py

@@ -26,6 +26,8 @@ class Options(usage.Options):
 
     optParameters = [
         ("port", "p", "tcp:4001:interface=\:\:", "endpoint to listen on"),
+        ("websocket", "w", None, "endpoint to listen for WebSocket connections"),
+        ("websocket-url", "u", None, "WebSocket URL (derived from endpoint if not provided)"),
         ("blur-usage", None, None, "blur timestamps and data sizes in logs"),
         ("log-fd", None, None, "write JSON usage logs to this file descriptor"),
         ("usage-db", None, None, "record usage data (SQLite)"),
@@ -38,8 +40,11 @@ class Options(usage.Options):
 def makeService(config, reactor=reactor):
     increase_rlimits()
     tcp_ep = endpoints.serverFromString(reactor, config["port"]) # to listen
-    # XXX FIXME proper websocket option
-    ws_ep = endpoints.serverFromString(reactor, "tcp:4002") # to listen
+    ws_ep = (
+        endpoints.serverFromString(reactor, config["websocket"])
+        if config["websocket"] is not None
+        else None
+    )
     log_file = (
         os.fdopen(int(config["log-fd"]), "w")
         if config["log-fd"] is not None
@@ -55,13 +60,22 @@ def makeService(config, reactor=reactor):
     tcp_factory = protocol.ServerFactory()
     tcp_factory.protocol = transit_server.TransitConnection
 
-    ws_factory = WebSocketServerFactory("ws://localhost:4002")  # FIXME: url
+    if ws_ep is not None:
+        ws_url = config["websocket-url"]
+        if ws_url is None:
+            # we're using a "private" attribute here but I don't see
+            # any useful alternative unless we also want to parse
+            # Twisted endpoint-strings.
+            ws_url = "ws://localhost:{}/".format(ws_ep._port)
+            print("Using WebSocket URL '{}'".format(ws_url))
+        ws_factory = WebSocketServerFactory(ws_url)
         ws_factory.protocol = transit_server.WebSocketTransitConnection
 
     tcp_factory.transit = transit
     ws_factory.transit = transit
     parent = MultiService()
     StreamServerEndpointService(tcp_ep, tcp_factory).setServiceParent(parent)
+    if ws_ep is not None:
         StreamServerEndpointService(ws_ep, ws_factory).setServiceParent(parent)
     TimerService(5*60.0, transit.update_stats).setServiceParent(parent)
     return parent