nixos: refactor dataspace server for TTYs

flake.nix

@@ -47,11 +47,11 @@
         syndicate-py = python3Packages.syndicate;
       }) self.legacyPackages;
 
+    nixosModules.default = self.nixosModules.syndicate-server;
     nixosModules.syndicate-server =
       # A little hack to apply our overlay to this module only.
-      let f = import ./nixos/syndicate-server.nix;
-      in { config, lib, pkgs, ... }:
-      f {
+      { config, lib, pkgs, ... }:
+      (import ./nixos/syndicate-server.nix) {
         inherit config lib;
         pkgs = pkgs.extend self.overlays.default;
       };

nixos/syndicate-server.nix

@@ -2,70 +2,95 @@
 with lib;
 
 {
-  options.services.syndicate-server = {
-    enable = mkEnableOption "the Syndicate dataspace server";
-
-    group = mkOption {
-      type = types.str;
-      default = "wheel";
-      example = "users";
-      description = "Group account under which the Syndicate server runs.";
-    };
-
-    package = mkOption {
-      default = pkgs.syndicate-server;
-      defaultText = "pkgs.syndicate-server";
-      type = types.package;
-      description = "The package to use for the Syndicate dataspace server.";
-    };
-
-    tcpListeners = mkOption {
-      default = [ ];
-      example = [{
-        address = "0.0.0.0";
-        port = 8001;
-      }];
-      type = with types;
-        listOf (submodule {
-          options = {
-            address = mkOption { type = str; };
-            port = mkOption { type = port; };
-          };
-        });
-      description = "TCP ports to listen for connections on.";
-    };
-
-    unixListeners = mkOption {
-      default = [ "/run/syndicate/ds" ];
-      type = types.listOf types.path;
-      description = "Sockets to listen for connections on.";
-    };
-
-  };
-
-  config = let cfg = config.services.syndicate-server;
-  in mkIf cfg.enable {
-
-    assertions = [{
-      assertion = cfg.tcpListeners == [ ];
-      message =
-        "tcpListeners configuration not implemented for Syndicate server";
-    }];
-
-    systemd.services.syndicate-server = {
-      description = "Syndicate dataspace server";
-      wantedBy = [ "multi-user.target" ];
-      serviceConfig = {
-        ExecStart = "${cfg.package}/bin/syndicate-server --no-banner ${
-            lib.strings.concatMapStrings (l: " --socket ${l}") cfg.unixListeners
-          }";
-        Group = cfg.group;
-        AmbientCapabilities = [ "CAP_NET_BIND_SERVICE" ];
-        DynamicUser = true;
-        Restart = "always";
-        RuntimeDirectory = "syndicate";
+  options.services.syndicate = mkOption {
+    default = { };
+    example = {
+      tty1 = {
+        enable = true;
+        user = "jane";
+        config = [ "/etc/syndicate" ];
       };
     };
+    description = ''
+      Syndicate dataspace server instances.
+      If the key is in the form of "tty''${N}" it will
+      be attached to the appropriate teletypwriter.
+    '';
+    type = types.attrsOf (types.submodule {
+      options = {
+        enable = mkEnableOption "this Syndicate dataspace server instance";
+
+        user = mkOption {
+          type = types.str;
+          example = "jane";
+          description = "User account under which the Syndicate server runs.";
+        };
+
+        package = mkOption {
+          default = pkgs.syndicate-server;
+          defaultText = "pkgs.syndicate-server";
+          type = types.package;
+          description =
+            "The package to use for the Syndicate dataspace server.";
+        };
+
+        config = mkOption {
+          type = types.listOf types.path;
+          description = "Configurations to load.";
+          example = [ "/etc/syndicate" ];
+        };
+
+      };
+    });
+  };
+
+  config = {
+
+    systemd.services = lib.attrsets.mapAttrs' (name: cfg: {
+      name = "syndicate-${name}";
+      value = let
+        flags = lib.strings.concatMapStrings (c: " --config ${c}") cfg.config;
+        serviceConfig = {
+          ExecStart =
+            "${cfg.package}/bin/syndicate-server --no-banner ${flags}";
+          User = cfg.user;
+        };
+      in if builtins.match "tty[0-9]" name != null then {
+        description = "Syndicate dataspace server";
+        after = [
+          "systemd-user-sessions.service"
+          "systemd-logind.service"
+          "getty@${name}.service"
+        ];
+        before = [ "graphical.target" ];
+        wants = [ "dbus.socket" "systemd-logind.service" ];
+        wantedBy = [ "graphical.target" ];
+        conflicts = [ "getty@${name}.service" ];
+
+        restartIfChanged = false;
+        unitConfig.ConditionPathExists = "/dev/${name}";
+
+        serviceConfig = serviceConfig // {
+          PAMName = "login";
+          StandardError = "journal";
+          StandardInput = "tty-fail";
+          StandardOutput = "journal";
+          TTYPath = "/dev/${name}";
+          TTYReset = "yes";
+          TTYVHangup = "yes";
+          TTYVTDisallocate = "yes";
+          UtmpIdentifier = "%n";
+          UtmpMode = "user";
+          WorkingDirectory = "~";
+        };
+      } else {
+        description = "Syndicate dataspace server";
+        wantedBy = [ "multi-user.target" ];
+        inherit serviceConfig;
+      };
+    })
+      (lib.attrsets.filterAttrs (_: cfg: cfg.enable) config.services.syndicate);
 
   };
+
 }