{ config, lib, pkgs, ... }:
with lib;
# unixODBC drivers (this solution is not perfect.. Because the user has to
# ask the admin to add a driver.. but it's simple and works
{
  ###### interface
  options = {
    environment.unixODBCDrivers = mkOption {
      type = types.listOf types.package;
      default = [];
      example = literalExample "with pkgs.unixODBCDrivers; [ mysql psql psqlng ]";
      description = ''
        Specifies Unix ODBC drivers to be registered in
        /etc/odbcinst.ini.  You may also want to
        add pkgs.unixODBC to the system path to get
        a command line client to connnect to ODBC databases.
      '';
    };
  };
  ###### implementation
  config = mkIf (config.environment.unixODBCDrivers != []) {
    environment.etc."odbcinst.ini".text =
      let inis = map (x : x.ini) config.environment.unixODBCDrivers;
      in lib.concatStringsSep "\n" inis;
  };
}