feat(nixos): migrate system configuration

configs/nixos/modules/services/copyparty.nix

@@ -0,0 +1,200 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  cfg = config.modules.services.copyparty;
+
+  volumeType = lib.types.submodule {
+    options = {
+      path = lib.mkOption {
+        type = lib.types.str;
+        description = "Filesystem path served by this volume.";
+      };
+
+      access = lib.mkOption {
+        type = lib.types.attrsOf (lib.types.listOf lib.types.str);
+        default = { };
+        example = {
+          A = [ "alexion" ];
+        };
+        description = "Copyparty access map from permission string to account names.";
+      };
+
+      flags = lib.mkOption {
+        type = lib.types.listOf lib.types.str;
+        default = [ ];
+        example = [ "dthumb" ];
+        description = "Copyparty volume flags.";
+      };
+    };
+  };
+
+  renderAccess = permission: accounts: "    ${permission}: ${lib.concatStringsSep ", " accounts}";
+
+  renderFlags = flags: lib.concatMapStringsSep "\n" (flag: "    ${flag}") flags;
+
+  renderVolume = urlPath: volume: ''
+    [${urlPath}]
+      ${volume.path}
+      accs:
+    ${lib.concatStringsSep "\n" (lib.mapAttrsToList renderAccess volume.access)}
+    ${lib.optionalString (volume.flags != [ ]) ''
+      flags:
+    ${renderFlags volume.flags}
+    ''}
+  '';
+
+  renderTrustedSource = source: "  xff-src: ${source}";
+
+  renderedReverseProxy = lib.optionalString cfg.reverseProxy.enable ''
+      rproxy: 1
+      xff-hdr: x-forwarded-for
+    ${lib.concatStringsSep "\n" (map renderTrustedSource cfg.reverseProxy.trustedSources)}
+  '';
+
+  renderedVolumes = lib.concatStringsSep "\n" (lib.mapAttrsToList renderVolume cfg.volumes);
+
+  configScript = pkgs.writeShellScript "copyparty-config" ''
+    set -eu
+
+    umask 077
+    password="$(${pkgs.coreutils}/bin/tr -d '\n' < "$CREDENTIALS_DIRECTORY/password")"
+
+    cat > /run/copyparty/copyparty.conf <<EOF
+    [global]
+      p: ${toString cfg.port}
+      usernames
+      http-only
+      no-crt
+      no-thumb
+      no-snap
+      no-rescan
+      ses-db: ${cfg.stateDir}/sessions.db
+      chpw-db: ${cfg.stateDir}/chpw.json
+      shr-db: ${cfg.stateDir}/shares.db
+    ${renderedReverseProxy}
+    [accounts]
+      ${cfg.accountName}: $password
+
+    ${renderedVolumes}
+    EOF
+  '';
+in
+{
+  options.modules.services.copyparty = {
+    enable = lib.mkEnableOption "Copyparty";
+
+    package = lib.mkPackageOption pkgs "copyparty-min" { };
+
+    port = lib.mkOption {
+      type = lib.types.port;
+      default = 3923;
+      description = "Port Copyparty listens on.";
+    };
+
+    user = lib.mkOption {
+      type = lib.types.str;
+      default = "copyparty";
+      description = "User account that runs Copyparty.";
+    };
+
+    group = lib.mkOption {
+      type = lib.types.str;
+      default = "storage";
+      description = "Group account that owns Copyparty's writable state and served files.";
+    };
+
+    accountName = lib.mkOption {
+      type = lib.types.str;
+      default = "alexion";
+      description = "Copyparty account name configured for password authentication.";
+    };
+
+    passwordFile = lib.mkOption {
+      type = lib.types.path;
+      description = "Runtime file containing the Copyparty account password.";
+    };
+
+    stateDir = lib.mkOption {
+      type = lib.types.str;
+      default = "/var/lib/copyparty";
+      description = "Directory where Copyparty stores service state.";
+    };
+
+    volumes = lib.mkOption {
+      type = lib.types.attrsOf volumeType;
+      default = { };
+      description = "Copyparty volumes keyed by their URL path.";
+    };
+
+    reverseProxy = {
+      enable = lib.mkEnableOption "reverse-proxy trust settings for Copyparty";
+
+      trustedSources = lib.mkOption {
+        type = lib.types.listOf lib.types.str;
+        default = [ ];
+        description = "IP ranges that may supply Copyparty's forwarded client IP header.";
+      };
+    };
+  };
+
+  config = lib.mkMerge [
+    {
+      registry."stable-uid".${config.networking.hostName}.copyparty = 20002;
+    }
+
+    (lib.mkIf cfg.enable {
+      assertions = [
+        {
+          assertion = cfg.volumes != { };
+          message = "modules.services.copyparty.volumes must declare at least one served volume.";
+        }
+        {
+          assertion = !cfg.reverseProxy.enable || cfg.reverseProxy.trustedSources != [ ];
+          message = "modules.services.copyparty.reverseProxy.trustedSources must name at least one trusted proxy source when reverse-proxy support is enabled.";
+        }
+      ];
+
+      users.users.${cfg.user} = {
+        isSystemUser = true;
+        uid = config.registry."stable-uid".${config.networking.hostName}.copyparty;
+        group = cfg.group;
+        home = cfg.stateDir;
+      };
+
+      systemd.services.copyparty = {
+        description = "Copyparty file server";
+        after = [ "network.target" ];
+        wantedBy = [ "multi-user.target" ];
+        serviceConfig = {
+          ReloadSignal = "SIGUSR1";
+          Type = "simple";
+          User = cfg.user;
+          Group = cfg.group;
+          WorkingDirectory = cfg.stateDir;
+          Environment = [
+            "HOME=${cfg.stateDir}"
+            "XDG_CONFIG_HOME=${cfg.stateDir}"
+          ];
+          StateDirectory = "copyparty";
+          RuntimeDirectory = "copyparty";
+          RuntimeDirectoryMode = "0700";
+          LoadCredential = [ "password:${cfg.passwordFile}" ];
+          ExecStartPre = configScript;
+          ExecStart = "${lib.getExe cfg.package} -c /run/copyparty/copyparty.conf";
+          Restart = "on-failure";
+          NoNewPrivileges = true;
+          PrivateTmp = true;
+          ProtectSystem = "strict";
+          ProtectHome = true;
+          ReadWritePaths = [ cfg.stateDir ] ++ map (volume: volume.path) (lib.attrValues cfg.volumes);
+        };
+      };
+
+      networking.firewall.allowedTCPPorts = [ cfg.port ];
+    })
+  ];
+}