nixos: adding nylon service with uid,gid

nixos/modules/misc/ids.nix

@@ -175,6 +175,7 @@
       gitlab = 165;
       tox-bootstrapd = 166;
       cadvisor = 167;
+      nylon = 168;
 
       # When adding a uid, make sure it doesn't match an existing gid. And don't use uids above 399!
 
@@ -313,6 +314,7 @@
       bosun = 161;
       kubernetes = 162;
       gitlab = 165;
+      nylon = 166;
 
       # When adding a gid, make sure it doesn't match an existing
       # uid. Users and groups with the same name should have equal

nixos/modules/module-list.nix

@@ -263,6 +263,7 @@
   ./services/networking/nsd.nix
   ./services/networking/ntopng.nix
   ./services/networking/ntpd.nix
+  ./services/networking/nylon.nix
   ./services/networking/oidentd.nix
   ./services/networking/openfire.nix
   ./services/networking/openntpd.nix

nixos/modules/services/networking/nylon.nix

@@ -0,0 +1,139 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.nylon;
+
+  homeDir = "/var/lib/nylon";
+
+  configFile = pkgs.writeText "nylon.conf" ''
+    [General]
+    No-Simultaneous-Conn=${toString cfg.nrConnections}
+    Log=${if cfg.logging then "1" else "0"}
+    Verbose=${if cfg.verbosity then "1" else "0"}
+
+    [Server]
+    Binding-Interface=${cfg.acceptInterface}
+    Connecting-Interface=${cfg.bindInterface}
+    Port=${toString cfg.port}
+    Allow-IP=${concatStringsSep " " cfg.allowedIPRanges}
+    Deny-IP=${concatStringsSep " " cfg.deniedIPRanges}
+  '';
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.nylon = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enables nylon as a running service upon activation.
+        '';
+      };
+
+      nrConnections = mkOption {
+        type = types.int;
+        default = 10;
+        description = ''
+          The number of allowed simultaneous connections to the daemon, default 10.
+        '';
+      };
+
+      logging = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enable logging, default is no logging.
+        '';
+      };
+
+      verbosity = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enable verbose output, default is to not be verbose.
+        '';
+      };
+
+      acceptInterface = mkOption {
+        type = types.string;
+        default = "lo";
+        description = ''
+          Tell nylon which interface to listen for client requests on, default is "lo".
+        '';
+      };
+
+      bindInterface = mkOption {
+        type = types.string;
+        default = "enp3s0f0";
+        description = ''
+          Tell nylon which interface to use as an uplink, default is "enp3s0f0".
+        '';
+      };
+
+      port = mkOption {
+        type = types.int;
+        default = 1080;
+        description = ''
+          What port to listen for client requests, default is 1080.
+        '';
+      };
+
+      allowedIPRanges = mkOption {
+        type = with types; listOf string;
+        default = [ "192.168.0.0/16" "127.0.0.1/8" "172.16.0.1/12" "10.0.0.0/8" ];
+        description = ''
+           Allowed client IP ranges are evaluated first, defaults to ARIN IPv4 private ranges:
+             [ "192.168.0.0/16" "127.0.0.0/8" "172.16.0.0/12" "10.0.0.0/8" ]
+        '';
+      };
+
+      deniedIPRanges = mkOption {
+        type = with types; listOf string;
+        default = [ "0.0.0.0/0" ];
+        description = ''
+          Denied client IP ranges, these gets evaluated after the allowed IP ranges, defaults to all IPv4 addresses:
+            [ "0.0.0.0/0" ]
+          To block all other access than the allowed.
+        '';
+      };
+    };
+  };
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    users.extraUsers.nylon= {
+      group = "nylon";
+      description = "Nylon SOCKS Proxy";
+      home = homeDir;
+      createHome = true;
+      uid = config.ids.uids.nylon;
+    };
+
+    users.extraGroups.nylon.gid = config.ids.gids.nylon;
+
+    systemd.services.nylon = {
+      description = "Nylon, a lightweight SOCKS proxy server";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig =
+      {
+        User = "nylon";
+        Group = "nylon";
+        WorkingDirectory = homeDir;
+        ExecStart = "${pkgs.nylon}/bin/nylon -f -c ${configFile}";
+      };
+    };
+  };
+}