modules: restructure modules directory

modules/devos/nix-path.nix

@@ -1,7 +1,7 @@
 { channel, inputs, ... }: {
   nix.nixPath = [
     "nixpkgs=${channel.input}"
-    "nixos-config=${../lib/compat/nixos}"
+    "nixos-config=${../../lib/compat/nixos}"
     "home-manager=${inputs.home}"
   ];
 }

modules/functionality/minecraft-servers/default.nix

@@ -0,0 +1,57 @@
+{ config, lib, pkgs, ... }@main:
+
+with lib;
+
+let
+  cfg = config.services.minecraft-servers;
+
+
+in
+{
+  options = (import ./options.nix) main;
+
+  config = mkIf cfg.enable {
+    users.users.minecraft = {
+      description = "Minecraft server service user";
+      home = cfg.dataDir;
+      createHome = true;
+      isSystemUser = true;
+      group = "minecraft";
+    };
+
+    users.groups.minecraft = { };
+
+    # systemd.services = mkIf (cfg.enable && cfg.servers != { }) ((import ./service.nix) main cfg);
+
+  };
+
+  # networking.firewall = let
+
+  #   propertyFunc = attrsets.mapAttrsToList (name: value:
+  #     let props = value.serverProperties;
+  #     in (if value.declarative then [
+  #       (props.server-port or 25565)
+  #       (if props.enable-rcon or false then
+  #         props."rcon.port" or 25575
+  #       else
+  #         null)
+  #       (if props.enable-query or false then
+  #         props "query.port" or 25565
+  #       else
+  #         null)
+  #     ] else
+  #       null)) cfg.servers;
+
+  #   openedPorts = lists.flatten [ serverPorts queryPorts rconPorts ];
+  # in {
+  #   allowedUDPPorts = openedPorts;
+  #   allowedTCPPorts = openedPorts;
+  # };
+
+  # assertions = [{
+  #   assertion = all (i: i.eula == true) (attrValues cfg.servers);
+  #   message = "You must agree to Mojangs EULA to run minecraft-server."
+  #     + " Read https://account.mojang.com/documents/minecraft_eula and"
+  #     + " set `services.minecraft-servers.servers.<name>.eula` to `true` for all servers if you agree.";
+  # }];
+}

modules/functionality/minecraft-servers/options.nix

@@ -0,0 +1,69 @@
+{ lib, ... }:
+with lib;
+{
+  services.minecraft-servers = {
+    enable = mkEnableOption "minecraft servers";
+    # TODO: verbose minecraft-servers enable option
+
+    openFirewall =
+      mkEnableOption "opening the firewall for each server by default";
+    # TODO: verbose outer openFirewall option
+
+    dataDir = mkOption {
+      type = types.path;
+      default = "/var/lib/minecraft";
+      # TODO: verbose dataDir option
+    };
+
+    servers = mkOption {
+      type = types.attrsOf (types.submodule {
+        enable = mkEnableOption "this minecraft server";
+        # TODO: verbose server enable option
+
+        declarative = mkEnableOption "declarative server management";
+        # TODO: verbose declarative option
+
+        eula = mkEnableOption "accepting the eula";
+        # TODO: verbose eula option
+
+        openFirewall = mkOption {
+          type = types.bool;
+          default = true; # cfg.openFirewall;
+          # TODO: openFirewall description
+        };
+
+        jvmOpts = mkOption {
+          type = types.separatedString " ";
+          default = "-Xmx2048M -Xms2048M";
+          # TODO: verbose jvmOpts option
+        };
+
+        package = mkOption {
+          type = types.package;
+          default = pkgs.minecraft-server;
+          # TODO: verbose package option
+        };
+
+        whitelist = mkOption {
+          type =
+            let
+              minecraftUUID = types.strMatching
+                "[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}"
+              // {
+                description = "Minecraft UUID";
+              };
+            in
+            types.attrsOf minecraftUUID;
+          default = { };
+          # TODO: verbose whitelist option
+        };
+
+        serverProperties = mkOption {
+          type = with types; attrsOf (oneOf [ bool int str ]);
+          default = { server-port = 25565; };
+          # TODO: verbose serverProperties option
+        };
+      });
+    };
+  };
+}

modules/functionality/minecraft-servers/service.nix

@@ -0,0 +1,95 @@
+{ pkgs, lib, ... }: cfg:
+
+with lib;
+let
+  eulaFile = builtins.toFile "eula.txt" ''
+    # eula.txt managed by NixOS Configuration
+    eula=true
+  '';
+
+  whitelistFile = server:
+    pkgs.writeText "whitelist.json" (builtins.toJSON (mapAttrsToList
+      (n: v: {
+        name = n;
+        uuid = v;
+      })
+      server.whitelist));
+
+
+  serverPropertiesFile =
+    let
+      cfgToString = v: if builtins.isBool v then boolToString v else toString v;
+    in
+    (server:
+      pkgs.writeText "server.properties" (''
+        # server.properties managed by NixOS configuration
+      '' + concatStringsSep "\n"
+        (mapAttrsToList (n: v: "${n}=${cfgToString v}") server.serverProperties)));
+
+  tmux = "${getBin pkgs.tmux}/bin/tmux";
+
+  stopScript = name:
+    pkgs.writeScript "minecraft-stop" ''
+      #!${pkgs.runtimeShell}
+
+      if ! [ -d "/proc/$1" ]; then
+        exit 0
+      fi
+
+      ${tmux} -S ${cfg.dataDir}/${name}.sock send-keys Enter stop Enter
+      ${getBin pkgs.coreutils}/bin/tail --pid-"$1" -f /dev/null
+    '';
+
+  mkService = (name: inst: nameValuePair
+    ("minecraft-server-${name}")
+    ({
+      description = "Minecraft Server Service: ${name}";
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" ];
+
+      serviceConfig = {
+        ExecStart = ''
+          ${tmux} -S ${cfg.dataDir}/${name}.sock new \
+            -d ${inst.package}/bin/minecraft-server ${inst.jvmOpts}
+        '';
+        ExecStop = "${stopScript name} $MAINPID";
+        Restart = "always";
+        Type = "forking";
+        GuessMainPIP = true;
+        User = "minecraft";
+        WorkingDirectory = "${cfg.dataDir}/${name}";
+      };
+
+      preStart = ''
+        ln -sf ${eulaFile} eula.txt
+      '' + (if inst.declarative then ''
+        if [ -e .declarative ]; then
+          # Was declarative before, no need to back up anything
+          ln -sf ${whitelistFile inst} whitelist.json
+          cp -f ${serverPropertiesFile inst} server.properties
+        else
+          # Declarative for the first time, backup stateful files
+          ln -sb --suffix=.stateful ${whitelistFile inst} whitelist.json
+          cp -b --suffix=.stateful ${
+            serverPropertiesFile inst
+          } server.properties
+          # server.properties must have write permissions, because every time
+          # the server starts it first parses the file and then regenerates it..
+          chmod +w server.properties
+          echo "Autogenerated file that signifies that this server configuration is managed declaratively by NixOS" \
+            > .declarative
+        fi
+      '' else ''
+        if [ -e .declarative ]; then
+          rm .declarative
+        fi
+      '');
+
+      postStart = ''
+        ${pkgs.coreutils}/bin/chmod 660 ${cfg.dataDir}/${name}.sock
+        ${pkgs.coreutils}/bin/chgrp minecraft ${cfg.dataDir}/${name}.sock
+      '';
+    })
+  );
+in
+flip mapAttrs' cfg.servers mkService