Files
Sovran_SystemsOS/modules/bitcoin/lndconnect.nix
T
Sovran Systems 2ea1427766 fix: restore a Zeus-scannable LND REST connect QR
The LND-only rewrite of lndconnect.nix shipped a wrapper Zeus cannot
use: unknown flags (--cert/--macaroon), a non-existent onion path
(free/lnd.onion), and a REST hidden service that collided with LND's
P2P onion. Restore the nix-bitcoin contract — dedicated lnd-rest
onion on port 8080, --nocert over Tor, admin macaroon in the URI —
and only persist a valid lndconnect:// URI for the Hub QR.
2026-08-17 18:22:36 -05:00

116 lines
3.6 KiB
Nix

{ config, lib, pkgs, ... }:
# LND-only lndconnect wrapper. Restored to the fort-nix/nix-bitcoin contract
# after the LND-only rewrite shipped a Zeus QR that Zeus cannot use:
# - unknown flags (--cert / --macaroon instead of --tlscertpath / --adminmacaroonpath)
# - onion hostname read from /var/lib/tor/onion/free/lnd/hostname (does not exist)
# - REST hidden service named "lnd", colliding with the LND P2P onion
# - TLS cert embedded in the URI (localhost CN + QR too dense to scan)
#
# Zeus needs: lndconnect://<lnd-rest-onion>:8080?macaroon=<admin> (no cert over Tor)
with lib;
let
cfg = config.services.lnd;
operatorName = config.nix-bitcoin.operator.name;
nbLib = config.nix-bitcoin.lib;
runAsUser = config.nix-bitcoin.runAsUserCmd;
mkLndconnect = {
name,
shebang ? "#!${pkgs.stdenv.shell} -e",
port,
authSecretPath,
enableOnion,
onionService ? null,
certPath ? null
}:
# lndconnect requires a --configfile argument, although it's unused
# https://github.com/LN-Zap/lndconnect/issues/25
lib.hiPrio (pkgs.writeScriptBin name ''
${shebang}
url=$(
${getExe pkgs.lndconnect} --url \
${optionalString enableOnion "--host=$(cat ${config.nix-bitcoin.onionAddresses.dataDir}/${onionService})"} \
--port=${toString port} \
${if enableOnion || certPath == null then "--nocert" else "--tlscertpath='${certPath}'"} \
--adminmacaroonpath='${authSecretPath}' \
--configfile=/dev/null "$@"
)
# If --url is in args
if [[ " $* " =~ " --url " ]]; then
echo "$url"
else
# UTF-8 QR is smaller than lndconnect's native output
echo -n "$url" | ${getExe pkgs.qrencode} -t UTF8 -o -
fi
'');
in {
options.services.lnd.lndconnect = {
enable = mkOption {
type = types.bool;
default = false;
description = ''
Add a `lndconnect` binary to the system environment which prints
connection info for lnd clients (Zeus).
See: https://github.com/LN-Zap/lndconnect
Usage:
```bash
# Print QR code
lndconnect
# Print URL
lndconnect --url
```
'';
};
onion = mkOption {
type = types.bool;
default = false;
description = ''
Create an onion service for the lnd REST server,
which is used by lndconnect / Zeus.
'';
};
};
config = mkIf (cfg.enable && cfg.lndconnect.enable) (mkMerge [
{
environment.systemPackages = [(
mkLndconnect {
name = "lndconnect";
# Run as lnd user because the macaroon and cert are not group-readable
shebang = "#!/usr/bin/env -S ${runAsUser} ${cfg.user} ${pkgs.bash}/bin/bash";
enableOnion = cfg.lndconnect.onion;
onionService = "${cfg.user}/lnd-rest";
port = cfg.restPort;
certPath = cfg.certPath;
authSecretPath = "${cfg.networkDir}/admin.macaroon";
}
)];
# LAN / clearnet Zeus needs REST on all interfaces. Tor-only stays on
# the existing restAddress (loopback) and is reached via lnd-rest.
services.lnd.restAddress = mkIf (!cfg.lndconnect.onion) "0.0.0.0";
}
(mkIf cfg.lndconnect.onion {
services.tor = {
enable = true;
# Dedicated name — must not reuse onionServices.lnd (that's P2P :9735).
relay.onionServices.lnd-rest = nbLib.mkOnionService {
target.addr = nbLib.address cfg.restAddress;
target.port = cfg.restPort;
port = cfg.restPort;
};
};
nix-bitcoin.onionAddresses.access = {
${cfg.user} = [ "lnd-rest" ];
${operatorName} = [ "lnd-rest" ];
};
})
]);
}