• Gnar
  • Features
  • Installation
  • Quick Start
  • Configuration
    • Command line flags
      • Server
      • Client
    • Configuration Files
      • Client Configuration (client_config.toml)
      • Server Configuration (server_config.toml)
    • Positional Arguments
      • Server
      • Client
  • Advanced Usage
    • Subdomain Proxy
    • Deploying on fly.io
  • Environment Variables
    • Server
    • Client
  • Trubleshooting
  • Contributing
  • Credits
  • License

Gnar

A Versatile Proxy Tool with Auto-HTTPS Subdomain Support.

Gnar is a powerful and flexible proxy tool, similar to frp, with built-in support for Auto-HTTPS subdomain proxying. It's designed to be simple yet feature-rich, making it an ideal solution for developers who need a reliable and secure proxy setup.

Features

• Simple implementation with minimal third-party dependencies
• Client graceful shutdown.
• Support for TCP/UDP traffic forwarding
• Subdomain proxy using Caddy server
• Configurable via command-line flags or a configuration file
• Multi-client forwarding support
• Token-based authentication for enhanced security
• Server-side admin panel for easy management
• Integration of yamux for multiplexing connections
• Deployable on fly.io

Installation

git clone https://github.com/abcdlsj/gnar
make

Quick Start

1. Start the server: with positional argument:

   gnar server 8910

   with flag:

   gnar server -p 8910

   Or using a configuration file:

   gnar server -c server_config.toml

2. Start the client: with positional argument:

   gnar client localhost:8910 3000:9001

   with flag:

   gnar client -s localhost:8910 -p 3000:9001

   Or using a configuration file:

   gnar client -c client_config.toml

3. Start a sample service:

   python3 -m http.server 3000

4. Access your service at localhost:9001

Configuration

Gnar supports both command-line flags and configuration files. Here's a sample client configuration:

Command line flags

Server

Run gnar server with optional port argument

Usage:
  gnar server [port] [flags]

Flags:
  -a, --admin-port int          admin server port
  -s, --caddy-srv-name string   caddy server name (default "srv0")
  -c, --config string           config file
  -D, --domain string           domain name
  -d, --domain-tunnel           enable domain tunnel
  -h, --help                    help for server
  -m, --multiplex               multiplex client/server control connection
  -p, --port int                server port (default 8910)
  -t, --token string            token

Client

Run gnar client with optional server address and port mapping

Usage:
  gnar client [server-addr] [local-port:remote-port] [flags]

Flags:
  -c, --config string        config file
  -h, --help                 help for client
  -m, --multiplex            multiplex client/server control connection
  -n, --proxy-name string    proxy name
  -y, --proxy-type string    proxy transport protocol type (default "tcp")
  -s, --server-addr string   server addr (default "localhost:8910")
      --speed-limit string   speed limit
  -d, --subdomain string     subdomain
  -t, --token string         token

Configuration Files

Client Configuration (client_config.toml)

server-addr = "localhost:8910"
token = "abcdlsj" # optional
multiplex = true # optional, if true will use yamux to multiplex the connection

[[proxys]]
proxy-name = "python_http_file_service" # optional
subdomain = "python3-http" # optional, if not set, will generate a random subdomain prefix
local-port = 3000
remote-port = 9001
speed-limit = "100kb" # optional, if not set, will not limit speed
proxy-type = "tcp"

[[proxys]]
local-port = 3001
remote-port = 9002
proxy-type = "tcp"

Server Configuration (server_config.toml)

port = 8910
admin-port = 8911
domain-tunnel = false
domain = "example.com"
# token = "abcdlsj" # optional
multiplex = false

Server admin panel:

Positional Arguments

Server

The server command accepts an optional port number as a positional argument:

gnar server [port]

If not provided, the default port (8910) or the port specified in the configuration file will be used.

Client

The client command accepts two optional positional arguments:

gnar client [server-addr] [local-port:remote-port]

1. server-addr: The address of the gnar server (e.g., "localhost:8910")
2. local-port:remote-port: The local and remote port mapping (e.g., "3000:9001")

If these arguments are not provided, the values from the configuration file or default values will be used.

Advanced Usage

Subdomain Proxy

Warning

This need you have the base knowledge of caddy and caddy plugin.

1. Set up your domain's DNS records:

   A *.example.com <your server ip>
   A example.com <your server ip>
   

2. Start the Caddy server(or if you have running caddy, you can skip this step):

   caddy run --config <gnar path>/configs/caddy.json

3. Run the Gnar server with domain tunnel enabled:

   gnar server 8910 -D example.com -d

   can use -s to set caddy server name(default should be srv0).

   gnar will use this name to create add new route.

   if you use Caddyfile to config caddy, you can use sudo caddy adapt --config /etc/caddy/Caddyfile to generate caddy.json.

4. Start the client with a custom subdomain:

   gnar client localhost:8910 3000:9001 -d myapp

Deploying on fly.io

Gnar can be easily deployed on https://fly.io.

Warning

I haven't tested it for a long time, it may need to be updated.

You can edit entrypoint.sh to start your own server you need to special set forward port.

Example:

# See https://fly.io/docs/reference/configuration/ for information about how to use this file.
app = "xxxx"
primary_region = "hkg"

[build]

# Control
[[services]]
  internal_port = 8910
  protocol = "tcp"

  [[services.ports]]
    port = 8910
  
# Admin
[[services]]
  internal_port = 8911
  protocol = "tcp"

  [[services.ports]]
    handlers = ["http"]
    port = 80

  [[services.ports]]
    handlers = ["tls", "http"]
    port = 443

# Forward TCP
[[services]]
  internal_port = 9000
  protocol = "tcp"

  [[services.ports]]
    handlers = ["tls", "http"]
    port = 9000

Run with fly launch.

After deployment, you can view xxxx.fly.dev:9000 and then view your own internal server.

Environment Variables

Gnar uses Viper to manage configuration, which allows for setting options via environment variables. The following environment variables are supported:

Server

• GNAR_PORT: Server port
• GNAR_ADMIN_PORT: Admin server port
• GNAR_DOMAIN_TUNNEL: Enable domain tunnel (true/false)
• GNAR_DOMAIN: Domain name
• GNAR_TOKEN: Authentication token
• GNAR_MULTIPLEX: Enable connection multiplexing (true/false)

Client

• GNAR_TOKEN: Authentication token
• GNAR_MULTIPLEX: Enable connection multiplexing (true/false)

Environment variables take precedence over configuration files and command-line flags. To use an environment variable, prefix the uppercase option name with GNAR_. For example, to set the server port:

export GNAR_PORT=8080
gnar server

This will start the server on port 8080, regardless of the default value or any value specified in a configuration file.

Trubleshooting

1. subdomain proxy not work

make sure you have set the dns record to your server ip. if you use cloudflare, need to set dns_key in caddy.json.

Contributing

We welcome contributions to Gnar! Please read our Contributing Guidelines for more information on how to get started.

Credits

Thanks to JetBrains for providing free licenses to support this project.

License

Gnar is released under the MIT License.