Re: sysinst split project - The Configuration File

[David Holland <dholland-current%netbsd.org@localhost>]

On Fri, Dec 11, 2009 at 02:16:44PM -0600, David Young wrote:
 > Use XML for the configuration.  That ensures that the configuration is
 > queryable/transformable with NetBSD's forthcoming xmltools.  I know that
 > writing XML by hand is objectionable, so establish a one-to-one mapping
 > from your user-friendly format to an XML format.  Provide a tool to/from
 > the XML format.

I'm going to stick my oar in to make four observations:

  1. Most of the rest of this thread is conflating *configuration* and
*scripting*. Configuration should not be Turing-complete, because it
becomes unmanageable. (See "sendmail".) Scripting is Turing-complete
by definition.

  2. Scripting should be done in a programming language. XML has no
legitimate business in this department.

  3. Configuration should be done in a concise and legible format,
such as key/value pairs, nested key/value pairs, columnar tables, or
whatever. Since XML is content-free^W^W just syntax, any such sane
format can easily be represented as XML. (As long as the data remains
strictly hierarchical and isn't, say, graph-structured. But that's not
likely to be a problem here.)

  4. Parsers are cheap. Sysadmins' time and sanity isn't.


If you have both configuration and scripting, the configuration data
should be made available (as data, in a clearly defined schema) to the
user scripts.

-- 
David A. Holland
dholland%netbsd.org@localhost