m17web-proxy

M17 web proxy that connects to M17 reflectors and streams audio/data to WebSocket clients.

Reflector discovery uses the ham-dht distributed hash table network via OpenDHT as the primary method. When a reflector is not found on the DHT, the proxy falls back to the RefCheck.Radio M17 host file for address resolution.

Configuration

Environment variables:

Variable	Description	Default
M17WEB_PROXY_CALLSIGN	Callsign of the proxy	SWLXXXXX
M17WEB_PROXY_LISTENER	Address:Port to listen on	0.0.0.0:3000
M17WEB_PROXY_SUBSCRIPTION	Format is Designator_Modules,Designator_Modules, ...	M17-XOR_ABC
M17WEB_PROXY_DHT_BOOTSTRAP	Bootstrap node for the ham-dht network	xrf757.openquad.net
M17WEB_PROXY_DHT_PORT	Port for the ham-dht bootstrap node	17171
M17WEB_PROXY_HOSTFILE_URL	URL for the M17 reflector host file (fallback)	https://hostfiles.refcheck.radio/M17Hosts.json
RUST_LOG	Log level (e.g. info, debug, warn)	(unset — defaults to error)

Docker

docker build -t m17web-proxy .

docker run -dp 3000:3000 --name m17web-proxy \
  -e M17WEB_PROXY_SUBSCRIPTION=M17-XOR_ABC,M17-DEV_DEF \
  m17web-proxy

Build

Tested on Ubuntu 24.04

Install dependencies:

sudo apt update && sudo apt install -y \
  curl build-essential pkg-config libssl-dev \
  cmake ninja-build \
  libgnutls28-dev libmsgpack-dev libargon2-dev \
  libasio-dev libfmt-dev nettle-dev \
  libclang-dev clang

curl https://sh.rustup.rs -sSf | bash -s -- -y
PATH="$HOME/.cargo/bin:${PATH}"

Clone and build:

git clone https://github.com/OE3ANC/m17web-proxy
cd m17web-proxy
cargo build --release
./target/release/m17web-proxy

How it works

At startup, the proxy:

1. Initializes an OpenDHT node and bootstraps into the ham-dht network
2. Fetches the M17 host file from RefCheck.Radio as a fallback data source (in parallel with DHT bootstrap)
3. For each subscribed reflector (e.g., M17-XOR):
   • First tries to resolve the address via DHT lookup
   • If DHT lookup fails, falls back to the host file data
   • Logs a warning when DHT fails and fallback is used
4. Connects to each reflector module via UDP
5. Streams received M17 voice/data frames to connected WebSocket clients

The ham-dht network is a decentralized system where M17 reflectors publish their configuration directly. The host file from RefCheck.Radio serves as a fallback for reflectors that are not registered on the DHT or when the DHT bootstrap is not working.