How to fix the Unix configuration nightmare

Unix is steadily evolving into something much easier to use. The trick is to find tools that make things more friendly, but fit in well with existing tools and are easier for people to take and use for new projects.

The Linux distributions and the BSD ports system are like this, taking an existing wealth of software and working with its quirks to streamline the installation and upgrading of applicaitons and system software.

GNU have done a lot of good work in standardising the compilation of software on different operating systems (automake and configure), parsing command line options (getopts), and internationalisation (gettext).

One this that's still a mess, however, is configuring applications

There are useful general trends, like putting system-wise configuration in /etc, and personal preferences in files beginning with . in your home folder.

However, there is a complete zoo of configuration file formats. Some use the old Windows .INI format. Others use simple variable assignments. And some use natural language style syntax.

Now a certain amount of diversity is healthy. But in this case it makes it a bit of a black art to build user-friendly and powerful configuration tools for all the software on a machine.

There have been various noble attempts.

Some popular packages, like apache and samba, have had point-and-click front-ends built for them. But each front-end works differently. Other packages, notably the linux kernel and Debian debconf, have a range of different interfaces depending on the user's taste, from a raw text file and vi, to a text-based menu system, to graphical point-and-click.

Another approach is to custom build a consistent set of front ends for a lot of different software configurations, such as the GNOME and KDE control panels, the linuxconf project, and dotfile.

I don't think I need to go into much detail as to what a mess the Windows registry is. It does provide a certain amount of power for graphical applications, but the text-level access is shoddy and cryptic, and a binary database seems to be an inherently unstable and inflexible way of storing data.

A new approach

But despite an apparent messy situation, I think that Unix may not be very far off from a workable solution.

Obviously it's possible - reports are that MacOS X has pulled off a very nice graphical front-end to Unix. However, that front-end is the bit they're keeping closed, so the other Unix systems are going to build need something free.

The solution I think lies in combining the best of the approaches I listed above. It's vital that it be somehting that can work with existing programs, but also is attractive to developers to incorporate into new versions and new projects. Without integration into the applications, it's always going to be a bit of a dodgy hack (see linuxconf) that makes it difficult to change the configuration file in a variety of ways.

Like previous successful Unix evolutions, it needs to plug into current technology in a way that gives something back to the developer pretty quickly, and make it easy and inviting to be used in both existing and new projects. Getting the developer involved is crucial for making sure the configuration manager keeps up to date with changes in the application, which I believe is a big part of the success of standards like gettext and configure.

It needs to accomodate diversity (the opposite of the One Registry approach, which I think will never fly on Unix). And it needs to be tenacious: it should be useful even with minimal information, but take good advantage of as much information as is given.

It needs to help both the user and the developer. It helps the developer by automating and cleaning up the their configuration handling and documentation. It helps the user by providing flexibility and consistency.

Here's an outline of how it might work:

• A core system would handle parsing, verification and storage of text-based configuration files in one or two basic formats.

• The master copy of the configuration is always left in the native text files (in /etc and ~/.*). This is where linuxconf falls down, it starts keeping it's own copy of the configuration, which means if linuxconf takes over your system and then later something stuffs up, it's difficult to edit a text file the old way without losing linuxconf completely. Also keeping the master config in text means you can always use a text editor to fix a broken config when nothing else works. This is a good argument against using some sort of binary scheme (Windows Registry, SQL) for everything.

• In order for some features to work, it might be necessary for application developers to switch to the use of the configuration manager for their internal routines. However, this should be possible wihout breaking backward compatibiliy with the original configuration file format for most features.

• A key element would be the configuration format description file. This would list the configuration options for a given piece of software, giving for each one the name, type (boolean, list, string, etc.), options, category (for sub-sections within the config), and help text (short and long).

  It would be good to be able to write descriptions of how options relate to each other: e.g. one option might disable a bunch of other options.

  Ideally you would be able to add optional hints to help with layout of the options on the screen under various configuration editor systems.

  Done well this could be a big attraction for developers, because it could automate a lot of the work involved in managing configuration systems. By creating a single place for storing such info, it could be used to automatically generate and update all documenation: user guides, man pages, web page help, commented template system and user config files, and programmatic help output.

• Because so much language is involved in configuration options, it needs to be internationalised from the ground up.

• This core system would be kept small and efficient, so that it is easy to add into all sorts of projects without weighing them down. It would have interfaces in all of the common Unix languages: C, C++, perl, php, shell scripting, python, etc.

• Plugins would allow the addition of a lot of diversity, and would be of atleast two types:
  • File format plugins would allow the programming of new configuration file formats. This includes parsing, verification, editing, and writing. You could expect heaps of such plugins, preferably provided with an application, or by a third party. Some plugins might also allow the use of SQL tables (instead of text files) for storing preferences, however text would be generally enouraged unless there were specific reasons for a given app to use something else.

  • Editor plugins would give various methods for changing configuration files. One could be a wrapper on your favourite text editor, then there's text-based menus (curses), graphical (GNOME, KDE, etc.), distribution specific (e.g. Debian debconf), and web forms (useful for web applications that have a lot of configuration options). It should be possible to invoke an editor from within an application (using the application's File -> Preferences... menu, or a command line option) or directly from the command line (or a GUI equivalent that listed installed apps, like a control panel). It should also be possible to programmatically edit configurations, either through a standard command line, or through the various language bindings listed above. Network administrators would love such tools.
• It all needs to be language, distribution and operating system neutral, so as to avoid turning off any potential software developers who might find it useful.

With such a system Unix could go even further than Windows and Mac, providing the ease-of-use of graphical configuration, with the flexibility and security of remote text-based configuration, and the power of programmatic access to read and change configurations throughout the system.

If this seems like a good idea, then all we need is a team of programmers and documenters to write it. It seems like a lot of work, but with the right touch, and strategic initial energy, it would be something that attracted contributions from a lot of different angles.