configuration

[Eray Ozkural (exa)]

On Mon, Jan 08, 2001 at 12:23:24PM +0100, Thomas Lange wrote:
> Therfore cfengine scripts will get much smaller, because
> copy operation will be made using fcopy. This will also be some sort
> of changes in your script, but it will be an improvement.
> 

Well, yes. But that's not my point. Even if the scripts get smaller,
they will still be pretty low level and fragile. I wonder if there could be
some way to do that on a higher level. What I thought was something
like this... Please consider it a rough sketch.

  In /etc/fai/ there is a configuration which enlists the most general
variables. one of them is a CLUSTERS variable. For each such cluster
there is a cluster definition file. For instance,

/etc/fai/config:
  CLUSTERS=net9 borg

The system expects definition files for both kueppers and borg.

/etc/fai/net9.config:
  master_node = kueppers
  node_indexing = RANGE
  node_prefix = sweetmachine
  node_first = 0
  node_last = 10
  network_type = internet_ssh

/etc/fai/borg.config:
  master_node = borg
  node_indexing = CUSTOM
  node_indices = 00 01 03 04 05 ... 36 
  node_prefix = node
  network_type = private_net

What I mean is there should be a way to define a cluster installation
configuration without editing anything. Users should be able to select
their combination of options and there they go.

My initial analysis is that either autoconf or cfengine itself can be
used for this meta-configuration task. Basically, I'm talking about wrapping
FAI a bit :)

Of course, not everybody will be comfortable with this. So I've got a
great customization mechanism ;)

Each cluster definition can optionally override the configuration
by placing the file to override/add in a corresponding dir.

Let's say that borg cluster needs some additional/replacing scripts and
packages.
They would go in...

/etc/fai/borg/scripts
/etc/fai/borg/packages

This idea has been occuring to me for quite a long time, but I haven't
been able to communicate it in the previous mail. I expect your comments.

Thanks,

-- 
Eray (exa) Ozkural
Comp. Sci. Dept., Bilkent University, Ankara
e-mail: erayo at cs.bilkent.edu.tr
www: http://www.cs.bilkent.edu.tr/~erayo