Re: what to do w/ hosts

On Mon, 11 Mar 2002 at 11:19:07 +0000, Will Partain <[email protected]>
wrote:

> Folks, another tiny rumination on the "hosts quandary"...
>
> ...
>
> Jonathan Hogg is leading a charge (ARK TNG) based around the
> elimination of the special pleading for hosts.  I mused upon
> an alternative, namely to make hosts *entirely* special,
> i.e. not ARK things at all.  Daniel Hagerty hinted at
> support for the latter view and, when he gets time, he may
> say more (please do :-).

> Simply saying hosts can't be ARK things sounds draconian to
> me.  So another as-yet-unmentioned possibility is to draw
> some distinction between hosts-that-are-ARK-things and
> hosts-that-are-not.  The latter entity/ies run code for ARK
> things, but are something else (abstractly speaking).  The
> former (hosts-that-are-ARK-things) are "clean" ARK objects,
> no special pleading whatsoever.

It seems to me that some "magic" interfaces or assumptions are needed by
every computer language. Here are two elementary examples:

Where to start:
    C: main ()
       -- just another function to the compiler, but a magic
          name at runtime
    Pascal: program HelloWorld
       -- part of the language syntax

Printing:
    C: printf (...)
       -- just another function call to the compiler, but
          requires that function at runtime
    Python: print ...
       -- part of the language syntax

The benefit of describing hosts, packages, etc. in ARK XML instead of a
generic knowledge modeling language comes from Arusha's added magic--the
assumptions and interfaces that support system administration and
configuration.

Hosts, packages, and a few others have special Python level support, but the
same ARK XML representation as other things. This similarity makes it easier
for users to work with these objects, but hides some important details
(e.g., sidaiDeploy in package.py).

How hard is it to add another deployment type (say FTP or NFS)?  How hard is
it for user's to represent "host down" without internal support?

What is the right balance between explicitly defining everything in the XML
files and hiding everything in the Python code?