Merge pull request 'modules/syncthing-static-peers: init' (#1579) from kenji/clan-core:init/static-syncthing into main

Reviewed-on: https://git.clan.lol/clan/clan-core/pulls/1579

clanModules/flake-module.nix

@@ -17,6 +17,7 @@
     sunshine = ./sunshine;
     static-hosts = ./static-hosts;
     syncthing = ./syncthing;
+    syncthing-static-peers = ./syncthing-static-peers;
     thelounge = ./thelounge;
     trusted-nix-caches = ./trusted-nix-caches;
     user-password = ./user-password;

clanModules/syncthing-static-peers/README.md

@@ -0,0 +1,2 @@
+Statically configure syncthing peers through clan
+---

clanModules/syncthing-static-peers/default.nix

@@ -0,0 +1,91 @@
+{
+  lib,
+  config,
+  pkgs,
+  ...
+}:
+let
+  clanDir = config.clanCore.clanDir;
+  machineDir = clanDir + "/machines/";
+  syncthingPublicKeyPath = machines: machineDir + machines + "/facts/syncthing.pub";
+  machinesFileSet = builtins.readDir machineDir;
+  machines = lib.mapAttrsToList (name: _: name) machinesFileSet;
+  syncthingPublicKeysUnchecked = builtins.map (
+    machine:
+    let
+      fullPath = syncthingPublicKeyPath machine;
+    in
+    if builtins.pathExists fullPath then machine else null
+  ) machines;
+  syncthingPublicKeyMachines = lib.filter (machine: machine != null) syncthingPublicKeysUnchecked;
+  devices = builtins.map (machine: {
+    name = machine;
+    value = {
+      name = machine;
+      id = (builtins.readFile (syncthingPublicKeyPath machine));
+    };
+  }) syncthingPublicKeyMachines;
+in
+{
+  options.clan.static-syncthing-peers = {
+    excludeMachines = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      example = [ config.clanCore.machineName ];
+      default = [ ];
+      description = ''
+        Machines that should not be added.
+      '';
+    };
+  };
+
+  config.services.syncthing.settings.devices = (builtins.listToAttrs devices);
+
+  imports = [
+    {
+      # Syncthing ports: 8384 for remote access to GUI
+      # 22000 TCP and/or UDP for sync traffic
+      # 21027/UDP for discovery
+      # source: https://docs.syncthing.net/users/firewall.html
+      networking.firewall.interfaces."zt+".allowedTCPPorts = [
+        8384
+        22000
+      ];
+      networking.firewall.allowedTCPPorts = [ 8384 ];
+      networking.firewall.interfaces."zt+".allowedUDPPorts = [
+        22000
+        21027
+      ];
+
+      # Activates inotify compatibility on syncthing
+      # use mkOverride 900 here as it otherwise would collide with the default of the
+      # upstream nixos xserver.nix
+      boot.kernel.sysctl."fs.inotify.max_user_watches" = lib.mkOverride 900 524288;
+
+      services.syncthing = {
+        enable = true;
+        configDir = "/var/lib/syncthing";
+        group = "syncthing";
+
+        key = lib.mkDefault config.clan.secrets.syncthing.secrets."syncthing.key".path or null;
+        cert = lib.mkDefault config.clan.secrets.syncthing.secrets."syncthing.cert".path or null;
+      };
+
+      clanCore.facts.services.syncthing = {
+        secret."syncthing.key" = { };
+        secret."syncthing.cert" = { };
+        public."syncthing.pub" = { };
+        generator.path = [
+          pkgs.coreutils
+          pkgs.gnugrep
+          pkgs.syncthing
+        ];
+        generator.script = ''
+          syncthing generate --config "$secrets"
+          mv "$secrets"/key.pem "$secrets"/syncthing.key
+          mv "$secrets"/cert.pem "$secrets"/syncthing.cert
+          cat "$secrets"/config.xml | grep -oP '(?<=<device id=")[^"]+' | uniq > "$facts"/syncthing.pub
+        '';
+      };
+    }
+  ];
+}

docs/mkdocs.yml

@@ -64,6 +64,7 @@ nav:
           - reference/clanModules/sshd.md
           - reference/clanModules/static-hosts.md
           - reference/clanModules/sunshine.md
+          - reference/clanModules/syncthing-static-peers.md
           - reference/clanModules/syncthing.md
           - reference/clanModules/thelounge.md
           - reference/clanModules/trusted-nix-caches.md