refactor: split server modules into smaller more manageable files

modules/nixos-modules/server/forgejo/default.nix

@@ -0,0 +1,61 @@
+{
+  lib,
+  config,
+  ...
+}: let
+  const = import ./const.nix;
+  httpPort = const.httpPort;
+  sshPort = const.sshPort;
+  db_user = "forgejo";
+in {
+  imports = [
+    ./proxy.nix
+    ./database.nix
+    ./fail2ban.nix
+    ./impermanence.nix
+  ];
+
+  options.services.forgejo = {
+    subdomain = lib.mkOption {
+      type = lib.types.str;
+      description = "subdomain of base domain that forgejo will be hosted at";
+      default = "forgejo";
+    };
+  };
+
+  config = lib.mkIf config.services.forgejo.enable {
+    assertions = [
+      {
+        assertion = config.services.forgejo.settings.server.BUILTIN_SSH_SERVER_USER == config.users.users.git.name;
+        message = "Forgejo BUILTIN_SSH_SERVER_USER hardcoded value does not match expected git user name";
+      }
+    ];
+
+    services.forgejo = {
+      database = {
+        type = "postgres";
+        socket = "/run/postgresql";
+      };
+      lfs.enable = true;
+      settings = {
+        server = {
+          DOMAIN = "${config.services.forgejo.subdomain}.${config.host.reverse_proxy.hostname}";
+          HTTP_PORT = httpPort;
+          START_SSH_SERVER = true;
+          SSH_LISTEN_PORT = sshPort;
+          SSH_PORT = 22;
+          BUILTIN_SSH_SERVER_USER = "git";
+          ROOT_URL = "https://git.jan-leila.com";
+        };
+        service = {
+          DISABLE_REGISTRATION = true;
+        };
+        database = {
+          DB_TYPE = "postgres";
+          NAME = db_user;
+          USER = db_user;
+        };
+      };
+    };
+  };
+}