zerotier: add support for moons

nixosModules/clanCore/zerotier/default.nix

@@ -2,6 +2,10 @@
 let
   cfg = config.clan.networking.zerotier;
   facts = config.clanCore.secrets.zerotier.facts or { };
+  genMoonScript = pkgs.runCommand "genmoon" { nativeBuildInputs = [ pkgs.python3 ]; } ''
+    install -Dm755 ${./genmoon.py} $out/bin/genmoon
+    patchShebangs $out/bin/genmoon
+  '';
   networkConfig = {
     authTokens = [
       null
@@ -59,6 +63,17 @@ in
         zerotier network name
       '';
     };
+    moon = {
+      stableEndpoints = lib.mkOption {
+        type = lib.types.listOf lib.types.str;
+        default = [ ];
+        description = ''
+          Make this machine a moon.
+          Other machines can join this moon by adding this moon in their config.
+          It will be reachable under the given stable endpoints.
+        '';
+      };
+    };
     subnet = lib.mkOption {
       type = lib.types.nullOr lib.types.str;
       readOnly = true;
@@ -120,11 +135,18 @@ in
       systemd.services.zerotierone.serviceConfig.ExecStartPre = [
         "+${pkgs.writeShellScript "init-zerotier" ''
            cp ${config.clanCore.secrets.zerotier.secrets.zerotier-identity-secret.path} /var/lib/zerotier-one/identity.secret
+           zerotier-idtool getpublic /var/lib/zerotier-one/identity.secret > /var/lib/zerotier-one/identity.public
 
            ${lib.optionalString (cfg.controller.enable) ''
              mkdir -p /var/lib/zerotier-one/controller.d/network
              ln -sfT ${pkgs.writeText "net.json" (builtins.toJSON networkConfig)} /var/lib/zerotier-one/controller.d/network/${cfg.networkId}.json
            ''}
+           ${lib.optionalString (cfg.moon.stableEndpoints != []) ''
+             if [[ ! -f /var/lib/zerotier-one/moon.json ]]; then
+               zerotier-idtool initmoon /var/lib/zerotier-one/identity.public > /var/lib/zerotier-one/moon.json
+             fi
+             ${genMoonScript}/bin/genmoon /var/lib/zerotier-one/moon.json ${builtins.toFile "moon.json" (builtins.toJSON cfg.moon.stableEndpoints)} /var/lib/zerotier-one/moons.d
+           ''}
 
            # cleanup old networks
            if [[ -d /var/lib/zerotier-one/networks.d ]]; then

nixosModules/clanCore/zerotier/genmoon.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+
+import json
+import subprocess
+import sys
+from pathlib import Path
+from tempfile import NamedTemporaryFile
+
+
+def main() -> None:
+    if len(sys.argv) != 4:
+        print("Usage: genmoon.py <moon.json> <endpoint.json> <moons.d>")
+        sys.exit(1)
+    moon_json = sys.argv[1]
+    endpoint_config = sys.argv[2]
+    moons_d = sys.argv[3]
+
+    moon_json = json.loads(Path(moon_json).read_text())
+    moon_json["roots"][0]["stableEndpoints"] = json.loads(
+        Path(endpoint_config).read_text()
+    )
+
+    with NamedTemporaryFile("w") as f:
+        f.write(json.dumps(moon_json))
+        f.flush()
+        Path(moons_d).mkdir(parents=True, exist_ok=True)
+        subprocess.run(["zerotier-idtool", "genmoon", f.name], cwd=moons_d)
+
+
+if __name__ == "__main__":
+    main()