clightning: add TEoS watchtower plugin

README.md

@@ -77,6 +77,7 @@ NixOS modules ([src](modules/modules.nix))
     * [prometheus](https://github.com/lightningd/plugins/tree/master/prometheus): lightning node exporter for the prometheus timeseries server
     * [rebalance](https://github.com/lightningd/plugins/tree/master/rebalance): keeps your channels balanced
     * [summary](https://github.com/lightningd/plugins/tree/master/summary): print a nice summary of the node status
+    * [teos-watchtower-plugin](https://github.com/talaia-labs/rust-teos/tree/master/watchtower-plugin): watchtower client plugin to interact with an Eye of Satoshi tower
     * [zmq](https://github.com/lightningd/plugins/tree/master/zmq): publishes notifications via ZeroMQ to configured endpoints
   * [clightning-rest](https://github.com/Ride-The-Lightning/c-lightning-REST): REST server for clightning
   * [lnd](https://github.com/lightningnetwork/lnd) with support for announcing an onion service and [static channel backups](https://github.com/lightningnetwork/lnd/blob/master/docs/recovery.md)

modules/clightning-plugins/default.nix

@@ -17,6 +17,7 @@ in {
     ./feeadjuster.nix
     ./prometheus.nix
     ./summary.nix
+    ./teos-watchtower-plugin.nix
     ./zmq.nix
   ];
 

modules/clightning-plugins/teos-watchtower-plugin.nix

@@ -0,0 +1,52 @@
+{ config, lib, ... }:
+
+with lib;
+let cfg = config.services.clightning.plugins.teos-watchtower-plugin; in
+{
+  options.services.clightning.plugins.teos-watchtower-plugin = {
+    enable = mkEnableOption "TEoS - watchtower (clightning plugin)";
+    package = mkOption {
+      type = types.package;
+      default = config.nix-bitcoin.pkgs.teos.teos-watchtower-plugin;
+      defaultText = "config.nix-bitcoin.pkgs.teos.teos-watchtower-plugin";
+      description = "The package providing TEoS watchtower plugin binaries.";
+    };
+    port = mkOption {
+      type = types.int;
+      default = config.services.teos.api.port;
+      description = "tower API port.";
+    };
+    dataDir = mkOption {
+      type = types.path;
+      default = "${config.services.clightning.dataDir}/.watchtower";
+      description = "The data directory for teos-watchtower-plugin.";
+    };
+    watchtowerMaxRetryTime = mkOption {
+      type = types.int;
+      default = 900;
+      description = "the maximum time a retry strategy will try to reach a temporary unreachable tower before giving up.";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    services.clightning.extraConfig = ''
+      plugin=${cfg.package}/bin/watchtower-client
+      watchtower-port=${toString cfg.port}
+      watchtower-max-retry-time=${toString cfg.watchtowerMaxRetryTime}
+    '';
+
+    # FIXME: Some better way to propagate this env variable to clightning
+    # service? Unfortunately it seems the teos-watchtower-plugin does not
+    # support specifying the data directory using a plugin configuration in
+    # clightning's config.
+    #
+    # Ref.: https://github.com/talaia-labs/rust-teos/blob/master/watchtower-plugin/README.md#config-file-data-folder-and-first-bootstrap
+    # Without this configuration, the plugin fails to load because it can't
+    # access its home directory - thanks to service hardening, specifically
+    # options:
+    # ProtectHome=true, isSystemUser=true
+    systemd.services.clightning.environment = {
+      TOWERS_DATA_DIR = cfg.dataDir;
+    };
+  };
+}

pkgs/default.nix

@@ -21,7 +21,6 @@ let self = {
   secp256k1 = pkgs.callPackage ./secp256k1 { };
   spark-wallet = pkgs.callPackage ./spark-wallet { };
   teos = pkgs.callPackage ./teos { };
-  teos-watchtower-plugin = pkgs.callPackage ./teos { };
 
   nbPython3Packages = (pkgs.python3.override {
     packageOverrides = import ./python-packages self;

test/tests.nix

@@ -62,6 +62,7 @@ let
         nbPkgs = config.nix-bitcoin.pkgs;
         pluginPkgs = nbPkgs.clightning-plugins // {
           clboss.path = "${nbPkgs.clboss}/bin/clboss";
+          teos-watchtower-plugin.path = "${nbPkgs.teos.teos-watchtower-plugin}/bin/watchtower-client";
         };
       in map (plugin: pluginPkgs.${plugin}.path) enabled;
       # Torified 'dig' subprocesses of clboss don't respond to SIGTERM and keep