nexttraceweb

# NEXTTRACE WEB A lightweight web API server for NextTrace — run visual traceroutes from your browser.

[](https://hub.docker.com/r/tsosc/nexttraceweb) [](LICENSE) [中文](/nexttraceweb/README.zh-CN.html) | **English**

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Overview

NextTrace Web is a spin-off of the NextTrace project. It provides a simple web frontend and API server so you can run traceroutes and visualize results — including hop, IP, ASN, geolocation, domain, packet loss, and latency stats — entirely from your browser.

Reverse proxy note: This project uses WebSocket as its communication protocol. If you configure a reverse proxy, please refer to the Nginx config included in this repository. The provided Docker image already has Nginx reverse proxy built in.

Inspired by PING.PE — thanks for years of keeping that service alive and giving the community such a great reference.

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How To Use

Docker (Recommended)

docker pull tsosc/nexttraceweb
docker run --network host -d --privileged --name ntwa tsosc/nexttraceweb 127.0.0.1:30080
# Visit http://127.0.0.1:30080

Expose the service to the Internet through your own reverse proxy or gateway. This project does not ship an in-app login flow.

Custom Address & Port

Pass an address/port argument to docker run to override the default:

# Bind to localhost only
docker run --network host -d --privileged --name ntwa tsosc/nexttraceweb 127.0.0.1:30080

# Listen on all IPs, port 80
docker run --network host -d --privileged --name ntwa tsosc/nexttraceweb 80

# Listen on IPv6 loopback
docker run --network host -d --privileged --name ntwa tsosc/nexttraceweb [::1]:30080

Runtime Notes

• Health endpoint: GET /healthz
• The container now exits when gunicorn or nginx dies, so supervisors can restart it instead of leaving a half-dead process tree behind.
• nexttrace_error is now a structured payload with code and message, plus retry_after_seconds on rate-limit and capacity rejections.

Security Defaults

• Configure NTWA_SECRET_KEY in production. If omitted, the app generates a temporary random key and logs a warning.
• Recommended: set NTWA_TRUSTED_HOSTS=trace.example.com behind a reverse proxy.
• Set NTWA_SESSION_COOKIE_SECURE=true only when the outer proxy serves HTTPS.
• Abuse controls:
  • NTWA_MIN_START_INTERVAL_SECONDS
  • NTWA_MAX_ACTIVE_TRACES
  • NTWA_TRACE_IDLE_TIMEOUT_SECONDS
  • NTWA_TRACE_MAX_DURATION_SECONDS

External Auth Example

Minimal Nginx example with Basic Auth in front of the container:

server {
    listen 443 ssl http2;
    server_name trace.example.com;

    auth_basic "restricted";
    auth_basic_user_file /etc/nginx/.htpasswd;

    location / {
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_pass http://127.0.0.1:30080;
    }
}

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