Add support for global LXC config files

nixos/modules/module-list.nix

@@ -381,6 +381,7 @@
   ./virtualisation/containers.nix
   ./virtualisation/docker.nix
   ./virtualisation/libvirtd.nix
+  ./virtualisation/lxc.nix
   #./virtualisation/nova.nix
   ./virtualisation/openvswitch.nix
   ./virtualisation/virtualbox-guest.nix

nixos/modules/virtualisation/lxc.nix

@@ -0,0 +1,75 @@
+# LXC Configuration
+
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.virtualisation.lxc;
+
+in
+
+{
+  ###### interface
+
+  options.virtualisation.lxc = {
+    enable =
+      mkOption {
+        type = types.bool;
+        default = false;
+        description =
+          ''
+            This enables Linux Containers (LXC), which provides tools
+            for creating and managing system or application containers
+            on Linux.
+          '';
+      };
+
+    systemConfig =
+      mkOption {
+        type = types.lines;
+        default = "";
+        description =
+          ''
+            This is the system-wide LXC config. See lxc.system.conf(5).
+          '';
+      };
+
+    defaultConfig =
+      mkOption {
+        type = types.lines;
+        default = "";
+        description =
+          ''
+            Default config (default.conf) for new containers, i.e. for
+            network config. See lxc.container.conf(5).
+          '';
+      };
+
+    usernetConfig =
+      mkOption {
+        type = types.lines;
+        default = "";
+        description =
+          ''
+            This is the config file for managing unprivileged user network
+            administration access in LXC. See lxc-user-net(5).
+          '';
+      };
+
+  };
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    environment.systemPackages = [ pkgs.lxc ];
+
+    environment.etc."lxc/lxc.conf".text = cfg.systemConfig;
+    environment.etc."lxc/lxc-usernet".text = cfg.usernetConfig;
+    environment.etc."lxc/default.conf".text = cfg.defaultConfig;
+
+  };
+
+}

pkgs/os-specific/linux/lxc/default.nix

@@ -17,6 +17,8 @@ stdenv.mkDerivation rec {
   preConfigure = ''
     export XML_CATALOG_FILES=${docbook_xml_dtd_45}/xml/dtd/docbook/catalog.xml
     substituteInPlace doc/rootfs/Makefile.am --replace '@LXCROOTFSMOUNT@' '$out/lib/lxc/rootfs'
+    substituteInPlace configure.ac --replace '$sysconfdir/' '/etc/'
+    substituteInPlace configure.ac --replace '$${sysconfdir}/' '/etc/'
   '';
 
   configureFlags = [