tun

Introduction

This is a simple and efficient reverse proxy toolkit that expose servers behind a NAT to the internet, such as accessing local web server via the internet.

Usage

Developers can import tun packages to develop their own programs, import github.com/4396/tun/server development server program, import github.com/4396/tun/client development client program.

The server program need to implement authentication and load function, prototype as follows.

// AuthFunc using id and token to authorize a proxy.
type AuthFunc func(id, token string) error

// LoadFunc using loader to load a proxy with id.
type LoadFunc func(loader Loader, id string) error

At the same time the project also provides a default implementation, located in the github.com/4396/tun/cmd, support tcp and http two types of proxy.

~ go get github.com/4396/tun/cmd/tuns
~ go get github.com/4396/tun/cmd/tunc

For example, expose the local godoc service to internet.

1. Start godoc:

   godoc -http=:9090

2. Start tuns:

   ./tuns -c tuns.ini

    # tuns.ini
    [tuns]
    addr = ServerIP:7000 # or :7000
    http = ServerIP:7070 # or :7070
   
    [godoc]
    type = http
    token = hello
    domain = godoc.mydomain.com

3. Start tunc:

   ./tunc -c tunc.ini

    # tunc.ini
    [tunc]
    server = ServerIP:7000
   
    [godoc]
    addr = 127.0.0.1:9090 # or :9090
    token = hello

   Or do not use a configuration file:

   ./tunc -server=ServerIP:7000 -id=godoc -token=hello -addr=:9090

4. Resolve A record of godoc.mydomain.com to ServerIP.

   If there are many proxies, you can resolve wildcard domain name.

5. Use nginx, not necessary.

    server {
        listen       80;
        server_name  godoc.mydomain.com;
   
        # wildcard domain name
        # server_name  ~.mydomain.com;
   
        location / {
            proxy_pass http://localhost:7070;
            proxy_set_header Host $host;
        }
    }

Reference

• ngrok - https://github.com/inconshreveable/ngrok
• frp - https://github.com/fatedier/frp