Running a socket port, but cannot connect it by webcat.

[liaodalin19903]

I am running a service with moleculer-io:

const ApiGateway = require("moleculer-web");
const SocketIOService = require("moleculer-io");


const { ServiceBroker } = require("moleculer");
const broker = new ServiceBroker();

broker.createService({
  name: 'gateway',
  mixins: [ApiGateway, SocketIOService], //Should after moleculer-web
  settings: {
    port: 3020
  },
  events: {
    // handle connections of clients
    "socket.connected" (ctx) {
      console.log(`Socket ${ctx.socket.id} connected to ${ctx.nodeID}.` );
      ctx.emit("hello", "Connected successfully!");
    },

    "socket.disconnected" (ctx) {
      console.log(`Socket ${ctx.socket.id} disconnected from ${ctx.nodeID}`)
    },
    // handle incoming message from the connected client
    "socket.message" (ctx, data) {
      console.log(`Socket ${ctx.socket.id} sent message: ${data}`);
      // broadcast the message to all connected clients
      ctx.broadcast("message", data);
    },

  },
})

broker.start() 

and I check the port is open:

% nmap 127.0.0.1 -p 3020 
Starting Nmap 7.93 ( https://nmap.org ) at 2023-03-22 17:58 CST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00046s latency).

PORT     STATE SERVICE
3020/tcp open  cifs

but however I connect it by webcat get error:

% websocat -vvv ws://127.0.0.1:3020
[INFO  websocat::lints] Auto-inserting the line mode
[DEBUG websocat] Done third phase of interpreting options.
[DEBUG websocat] Done fourth phase of interpreting options.
[DEBUG websocat] Preparation done. Now actually starting.
[DEBUG websocat::sessionserve] Serving Line2Message(ThreadedStdio) to Message2Line(WsClient("ws://127.0.0.1:3020/")) with Options { websocket_text_mode: true, websocket_protocol: None, websocket_reply_protocol: None, udp_oneshot_mode: false, udp_broadcast: false, udp_multicast_loop: false, udp_ttl: None, udp_join_multicast_addr: [], udp_join_multicast_iface_v4: [], udp_join_multicast_iface_v6: [], udp_reuseaddr: false, unidirectional: false, unidirectional_reverse: false, max_messages: None, max_messages_rev: None, exit_on_eof: false, oneshot: false, unlink_unix_socket: false, unix_socket_accept_from_fd: false, exec_args: [], ws_c_uri: "ws://0.0.0.0/", linemode_strip_newlines: false, linemode_strict: false, origin: None, custom_headers: [], custom_reply_headers: [], websocket_version: None, websocket_dont_close: false, websocket_ignore_zeromsg: false, one_message: false, no_auto_linemode: false, buffer_size: 65536, broadcast_queue_len: 16, read_debt_handling: Warn, linemode_zero_terminated: false, restrict_uri: None, serve_static_files: [], exec_set_env: false, no_exit_on_zeromsg: false, reuser_send_zero_msg_on_disconnect: false, process_zero_sighup: false, process_exit_sighup: false, socks_destination: None, auto_socks5: None, socks5_bind_script: None, tls_domain: None, tls_insecure: false, headers_to_env: [], max_parallel_conns: None, ws_ping_interval: None, ws_ping_timeout: None, request_uri: None, request_method: None, request_headers: [], autoreconnect_delay_millis: 20, ws_text_prefix: None, ws_binary_prefix: None, ws_binary_base64: false, ws_text_base64: false, close_status_code: None, close_reason: None, asyncstdio: false, foreachmsg_wait_reads: false, announce_listens: false, timestamp_monotonic: false, print_ping_rtts: false, byte_to_exit_on: 28, max_ws_message_length: 209715200, max_ws_frame_length: 104857600, preamble: [], preamble_reverse: [], compress_deflate: false, compress_zlib: false, compress_gzip: false, uncompress_deflate: false, uncompress_zlib: false, uncompress_gzip: false }
[INFO  websocat::stdio_threaded_peer] get_stdio_peer (threaded)
[DEBUG websocat::sessionserve] Underlying connection established
[INFO  websocat::ws_client_peer] get_ws_client_peer
websocat: WebSocketError: WebSocket protocol error
websocat: error running

please tell me where is the issue.

[icebob]

moleculer.io is a Socket.IO mixin, not native websocket. You can test it with socketio-cli tool: