{ config, lib, pkgs, ... }: with lib; let options.services.lnd = { enable = mkEnableOption "Lightning Network daemon, a Lightning Network implementation in Go"; address = mkOption { type = types.str; default = "localhost"; description = "Address to listen for peer connections"; }; port = mkOption { type = types.port; default = 9735; description = "Port to listen for peer connections"; }; rpcAddress = mkOption { type = types.str; default = "localhost"; description = "Address to listen for RPC connections."; }; rpcPort = mkOption { type = types.port; default = 10009; description = "Port to listen for gRPC connections."; }; restAddress = mkOption { type = types.str; default = "localhost"; description = "Address to listen for REST connections."; }; restPort = mkOption { type = types.port; default = 8080; description = "Port to listen for REST connections."; }; dataDir = mkOption { type = types.path; default = "/var/lib/lnd"; description = "The data directory for LND."; }; networkDir = mkOption { readOnly = true; default = "${cfg.dataDir}/chain/bitcoin/${bitcoind.network}"; description = "The network data directory."; }; tor-socks = mkOption { type = types.nullOr types.str; default = if cfg.tor.proxy then config.nix-bitcoin.torClientAddressWithPort else null; description = "Socks proxy for connecting to Tor nodes"; }; macaroons = mkOption { default = {}; type = with types; attrsOf (submodule { options = { user = mkOption { type = types.str; description = "User who owns the macaroon."; }; permissions = mkOption { type = types.str; example = '' {"entity":"info","action":"read"},{"entity":"onchain","action":"read"} ''; description = "List of granted macaroon permissions."; }; }; }); description = '' Extra macaroon definitions. ''; }; certificate = { extraIPs = mkOption { type = with types; listOf str; default = []; example = [ "60.100.0.1" ]; description = '' Extra `subjectAltName` IPs added to the certificate. This works the same as lnd option `tlsextraip`. ''; }; extraDomains = mkOption { type = with types; listOf str; default = []; example = [ "example.com" ]; description = '' Extra `subjectAltName` domain names added to the certificate. This works the same as lnd option `tlsextradomain`. ''; }; }; extraConfig = mkOption { type = types.lines; default = ""; example = '' autopilot.active=1 ''; description = '' Extra lines appended to `lnd.conf`. See here for all available options: https://github.com/lightningnetwork/lnd/blob/master/sample-lnd.conf ''; }; package = mkOption { type = types.package; default = config.nix-bitcoin.pkgs.lnd; defaultText = "config.nix-bitcoin.pkgs.lnd"; description = "The package providing lnd binaries."; }; cli = mkOption { default = pkgs.writeScriptBin "lncli" # Switch user because lnd makes datadir contents readable by user only '' ${runAsUser} ${cfg.user} ${cfg.package}/bin/lncli \ --rpcserver ${cfg.rpcAddress}:${toString cfg.rpcPort} \ --tlscertpath '${cfg.certPath}' \ --macaroonpath '${networkDir}/admin.macaroon' "$@" ''; defaultText = "(See source)"; description = "Binary to connect with the lnd instance."; }; getPublicAddressCmd = mkOption { type = types.str; default = ""; description = '' Bash expression which outputs the public service address to announce to peers. If left empty, no address is announced. ''; }; user = mkOption { type = types.str; default = "lnd"; description = "The user as which to run LND."; }; group = mkOption { type = types.str; default = cfg.user; description = "The group as which to run LND."; }; certPath = mkOption { readOnly = true; default = "${secretsDir}/lnd-cert"; description = "LND TLS certificate path."; }; tor = nbLib.tor; }; cfg = config.services.lnd; nbLib = config.nix-bitcoin.lib; secretsDir = config.nix-bitcoin.secretsDir; runAsUser = config.nix-bitcoin.runAsUserCmd; lndinit = "${config.nix-bitcoin.pkgs.lndinit}/bin/lndinit"; bitcoind = config.services.bitcoind; bitcoindRpcAddress = nbLib.address bitcoind.rpc.address; networkDir = cfg.networkDir; configFile = pkgs.writeText "lnd.conf" '' datadir=${cfg.dataDir} logdir=${cfg.dataDir}/logs tlscertpath=${cfg.certPath} tlskeypath=${secretsDir}/lnd-key listen=${toString cfg.address}:${toString cfg.port} rpclisten=${cfg.rpcAddress}:${toString cfg.rpcPort} restlisten=${cfg.restAddress}:${toString cfg.restPort} bitcoin.${bitcoind.network}=1 bitcoin.active=1 bitcoin.node=bitcoind ${optionalString (cfg.tor.proxy) "tor.active=true"} ${optionalString (cfg.tor-socks != null) "tor.socks=${cfg.tor-socks}"} bitcoind.rpchost=${bitcoindRpcAddress}:${toString bitcoind.rpc.port} bitcoind.rpcuser=${bitcoind.rpc.users.${rpcUser}.name} bitcoind.zmqpubrawblock=${bitcoind.zmqpubrawblock} bitcoind.zmqpubrawtx=${bitcoind.zmqpubrawtx} wallet-unlock-password-file=${secretsDir}/lnd-wallet-password ${cfg.extraConfig} ''; isPruned = bitcoind.prune > 0; # When bitcoind pruning is enabled, lnd requires non-public RPC commands `getpeerinfo`, `getnodeaddresses` # to fetch missing blocks from peers (implemented in btcsuite/btcwallet/chain/pruned_block_dispatcher.go) rpcUser = if isPruned then "lnd" else "public"; in { inherit options; config = mkIf cfg.enable (mkMerge [ { assertions = [ { assertion = !(config.services ? clightning) || !config.services.clightning.enable || config.services.clightning.port != cfg.port; message = '' LND and clightning can't both bind to lightning port 9735. Either disable LND/clightning or change services.clightning.port or services.lnd.port to a port other than 9735. ''; } ]; services.bitcoind = { enable = true; # Increase rpc thread count due to reports that lightning implementations fail # under high bitcoind rpc load rpc.threads = 16; zmqpubrawblock = "tcp://${bitcoindRpcAddress}:28332"; zmqpubrawtx = "tcp://${bitcoindRpcAddress}:28333"; }; environment.systemPackages = [ cfg.package (hiPrio cfg.cli) ]; systemd.tmpfiles.rules = [ "d '${cfg.dataDir}' 0770 ${cfg.user} ${cfg.group} - -" ]; services.lnd.certificate.extraIPs = mkIf (cfg.rpcAddress != "localhost") [ "${cfg.rpcAddress}" ]; systemd.services.lnd = { wantedBy = [ "multi-user.target" ]; requires = [ "bitcoind.service" ]; after = [ "bitcoind.service" ]; preStart = '' install -m600 ${configFile} '${cfg.dataDir}/lnd.conf' { echo "bitcoind.rpcpass=$(cat ${secretsDir}/bitcoin-rpcpassword-${rpcUser})" ${optionalString (cfg.getPublicAddressCmd != "") '' echo "externalip=$(${cfg.getPublicAddressCmd})" ''} } >> '${cfg.dataDir}/lnd.conf' if [[ ! -f ${networkDir}/wallet.db ]]; then seed='${cfg.dataDir}/lnd-seed-mnemonic' if [[ ! -f "$seed" ]]; then echo "Create lnd seed" (umask u=r,go=; ${lndinit} gen-seed > "$seed") fi echo "Create lnd wallet" ${lndinit} -v init-wallet \ --file.seed="$seed" \ --file.wallet-password='${secretsDir}/lnd-wallet-password' \ --init-file.output-wallet-dir='${cfg.networkDir}' fi ''; serviceConfig = nbLib.defaultHardening // { Type = "notify"; RuntimeDirectory = "lnd"; # Only used to store custom macaroons RuntimeDirectoryMode = "711"; ExecStart = "${cfg.package}/bin/lnd --configfile='${cfg.dataDir}/lnd.conf'"; User = cfg.user; TimeoutSec = "15min"; Restart = "on-failure"; RestartSec = "10s"; ReadWritePaths = [ cfg.dataDir ]; ExecStartPost = let curl = "${pkgs.curl}/bin/curl -fsS --cacert ${cfg.certPath}"; restUrl = "https://${nbLib.addressWithPort cfg.restAddress cfg.restPort}/v1"; in # Setting macaroon permissions for other users needs root permissions nbLib.rootScript "lnd-create-macaroons" '' umask ug=r,o= ${lib.concatMapStrings (macaroon: '' echo "Create custom macaroon ${macaroon}" macaroonPath="$RUNTIME_DIRECTORY/${macaroon}.macaroon" ${curl} \ -H "Grpc-Metadata-macaroon: $(${pkgs.xxd}/bin/xxd -ps -u -c 99999 '${networkDir}/admin.macaroon')" \ -X POST \ -d '{"permissions":[${cfg.macaroons.${macaroon}.permissions}]}' \ ${restUrl}/macaroon |\ ${pkgs.jq}/bin/jq -c '.macaroon' | ${pkgs.xxd}/bin/xxd -p -r > "$macaroonPath" chown ${cfg.macaroons.${macaroon}.user}: "$macaroonPath" '') (attrNames cfg.macaroons)} ''; } // nbLib.allowedIPAddresses cfg.tor.enforce; }; users.users.${cfg.user} = { isSystemUser = true; group = cfg.group; extraGroups = [ "bitcoinrpc-public" ]; home = cfg.dataDir; # lnd creates .lnd dir in HOME }; users.groups.${cfg.group} = {}; nix-bitcoin.operator = { groups = [ cfg.group ]; allowRunAsUsers = [ cfg.user ]; }; nix-bitcoin.secrets = { lnd-wallet-password.user = cfg.user; lnd-key.user = cfg.user; lnd-cert.user = cfg.user; lnd-cert.permissions = "444"; # world readable }; # Advantages of manually pre-generating certs: # - Reduces dynamic state # - Enables deployment of a mesh of server plus client nodes with predefined certs nix-bitcoin.generateSecretsCmds.lnd = '' makePasswordSecret lnd-wallet-password makeCert lnd '${nbLib.mkCertExtraAltNames cfg.certificate}' ''; } (mkIf isPruned { services.bitcoind.rpc.users.lnd = { passwordHMACFromFile = true; rpcwhitelist = bitcoind.rpc.users.public.rpcwhitelist ++ [ "getpeerinfo" "getnodeaddresses" ]; }; nix-bitcoin.secrets = { bitcoin-rpcpassword-lnd.user = cfg.user; bitcoin-HMAC-lnd.user = bitcoind.user; }; nix-bitcoin.generateSecretsCmds.lndBitcoinRPC = '' makeBitcoinRPCPassword lnd ''; }) ]); }