Future of FAI (fwd)

[AUSTIN MURPHY]

On Wed, 27 Nov 2002, Bruce  Edge wrote:
> > One thing I'd like to see addressed it the order that the
> > script directory is processed.
> Files in class/ are processed by name, so are the script/CLASSNAME/* scripts.
> I think script/* ought to follow the same rules.
>
> I can't see any advantage to forcing script processing to occur in
> the same order in which classes were defined.

I see FAI as an extrordinarily complex system with which you can run a
script in any language, define any variable, and copy any file anywhere
you please, all for large numbers of dissimilar systems.  The class
system is, in my view, a way to impose some order on this massive system.
IMO, classes should be modular, offer a system of inheritance, and serve
as a accurate roadmap of how the Fully Automated Install should procede.

> What about the case where you define class inheritance via a spef file?
> Are class scripts processed in child->parent or parent->child
> inheritance order?

The patch I posted last week made no changes to how scripts are executed.
They still are executed in the order of precedence in which the classes
were defined.

My patch implements inheritance in the parent-before-child manner.  The
spec file for CHILD contains a line "Depends: PARENT".  In this sense,
DEFAULT is a parent for every class, and LAST is a parent to none.

Similarly, platform neutral classes should be defined before platform
specific classes and low level services and utilities should be defined
before user-land programs and graphical environments.

> Making it explicit, ie: by name ordering, you force the decision to
> the foreground, same as with the class/* files.

I think the ordering decision should be made when classes are defined and
then all other operations are implicitly ordered from then on.

Perhaps a special directory under scripts/ could be made to serve as a
home for scripts that should be executed in Alpha-Numeric order.   A
subset of scripts from that dir, based on the defined classes, would be
run in A/N order.  scripts/LINEAR/ might be a good name for this dir.

Austin