server: 408 error after about a minute of working

I am hosting the local tunnel server in an AWS ec2 instance, after setting up everything when, I try to connect from the client, the tunnel works for about a minute then shows HTTP ERROR 408.

site.conf from nginx/conf.d:

proxy_http_version 1.1;


server {
    listen 0.0.0.0:80;

    location / {
        proxy_pass http://127.0.0.1:3000/;

        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $http_host;
        proxy_set_header X-Forwarded-Proto http;
        proxy_set_header X-NginX-Proxy true;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;

        proxy_redirect off;
    }
}

nginx.conf:

user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  off;

    sendfile        on;
    #tcp_nopush     on;


    gzip  on;
    gzip_min_length  1000;

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites/*;
}

why does it work just for about a minute. I tried it from both CLI and API.

About this issue

Original URL
State: open
Created 10 months ago
Comments: 27

Most upvoted comments

After non stop debugging and testing the whole day and night, I (hopefully) found a solution. At least it works locally and has nothing todo with localhost / 127.0.0.1

This simple line in server/TunnelAgent.js makes the magic happen:

     // new socket connection from client for tunneling requests to client
     _onConnection(socket) {
         // no more socket connections allowed
         if (this.connectedSockets >= this.maxTcpSockets) {
             this.debug('no more sockets allowed');
             socket.destroy();
             return false;
         }

+        socket.on("data", () => { /* silence is golden */ });

         socket.once('close', (hadError) => {
             this.debug('closed socket (error: %s)', hadError);
             this.connectedSockets -= 1;

It ensures for some reason (didn’t look deeper into it for now) that the connection is getting reestablished after getting dropped. Without this line an important other event (don’t know which one for now) is not getting fired which results in broken sockets (9+1 as defined by default).

Will try to implement these changes on my live server as soon as I got some sleep and hopefully it works there too.

Example: Without this "fix": CleanShot 2023-09-22 at 04 29 11

With this "fix": CleanShot 2023-09-22 at 04 35 52

Tested on my VPS with success 🎉 Works with all versions of Node (16,18,20)

creazy231 on Sep 22, 2023

@tiagopazhs quick update after debugging the hell out of locatunnel and your repository of localTunnel-OpenSource:

I debugged the problem down to the net.connect since I figured out, that the local connection just drops with http error 408. The local connection which maps the local application to the client service.

As I thought, the reason is this: https://github.com/nodejs/node/issues/43776

I used your localTunnel-OpenSource to debug since socket.io and express just gives me more details when running it with DEBUG=*.

Now I’ll try to implement the changes I’ve made into localtunnel… let’s see

creazy231 on Sep 21, 2023

Exactly, 18 | 18/20 | 18 | 127.0.0.1/locahost is what we wanna get up and running. In fact - every time a user uses Node v18 or higher, localtunnel stops working after about 1 minute. I guess the socket connection just drops or something.

I already tried to update all dependencies to its latest version - with the same result - getting HTTP ERROR 408 after some time and dropping connection when max socket connection is reached.

Also thought about using socket.io for connection but it’s not that easy to make it work. Reason therefore is, that this repository uses socket.io (https://github.com/BenMcH/node-grok) and it simply works! But without a subdomain like localtunnel 😦

Will try to replace koa with express like you mentioned, maybe this gives me some other responses or ideas.

Were you able to reproduce the error I mentioned with the 408 http error?

creazy231 on Sep 21, 2023