class dependencies

[Ingo Wichmann]

Oh, I didn't see this ... same idea. I hope I get it in with the 
argumentation that the change has a very small footprint ... only one line 
in an existing file is changed.

Ingo

Raphaël Pinson schrieb:
> Hi Ingo,
> 
> Nice work.
> 
> I had sent a patch to FAI some months ago which allowed inherited 
> classes, but it never got taken into FAI, don't remember why [0].
> 
> 
> Raphael
> 
> [0] https://lists.uni-koeln.de/pipermail/linux-fai-devel/2008q1/000516.html
> 
> 
> On Tue, Sep 9, 2008 at 10:31 PM, Ingo Wichmann <iw at linuxhotel.de 
> <mailto:iw at linuxhotel.de>> wrote:
> 
>     Hi fai,
> 
>     I just wrote a script that implements dependencies between fai
>     classes and ask for including it in fai.
> 
>     how does it work?
>     put this script in $FAI/class and make it executable. Now,
>     e.g. you have a class WORDPRESS that depends on the classes VHOST
>     and POSTGRES . VHOST again may depend on WEBSERVER.
>     So if you want to install the blogging software wordpress, you add a
>     file
> 
>     $FAI/class/WORDPRESS.deps
> 
>     that contains the words
>     VHOST
>     POSTGRES
> 
>     and a file
>     $FAI/class/VHOST.deps
> 
>     that contains the word
>     WEBSERVER
> 
>     The order often is important, so this script is taking care of it.
>     The order of the example above would be:
>     WEBSERVER VHOST POSTGRES WORDPRESS
>     That way, in $FAI/scripts/ first the webserver would be configured,
>     then the vhosts, ...
> 
>     It removes double entries from FAI_CLASSES and handles circular
>     dependencies[1].
> 
> 
> 
>     Calling this file from withing defclass is not perfect: dependencies
>     for $HOSTNAME and LAST are not possible. A solution could be, to
>     call this script right after fai-class is called in task defclass.
> 
>     Somebody willing to include this? To do so 3 changes are necessary:
>     1. add a line
>      fai-deps
>     right after
>      fai-class -T $FAI/class $LOGDIR/FAI_CLASSES
>     in
>     /usr/lib/fai/subroutines ( task_defclass() )
>     2. add this script as
>     /usr/bin/fai-class
>     3. new dependency to libgraph-perl for fai-class
> 
>     It should not break existing configurations, because it only acts if
>     non-executable files $FAI/class/*.deps exist.
> 
>     Ingo
> 
> 
>     [1] I do not recommend using circular dependencies, but if you
>     accidentally define them, they will not break your neck. But you'll
>     get a warning ...
> 
>     -- 
>     Linuxhotel GmbH, Geschäftsführer Dipl.-Ing. Ingo Wichmann
>     HRB 20463 Amtsgericht Essen, UStID DE 814 943 641
>     Antonienallee 1, 45279 Essen, Tel.: 0201 8536-600,
>     http://www.linuxhotel.de
> 
> 


-- 
Linuxhotel GmbH, Geschäftsführer Dipl.-Ing. Ingo Wichmann
HRB 20463 Amtsgericht Essen, UStID DE 814 943 641
Antonienallee 1, 45279 Essen, Tel.: 0201 8536-600, http://www.linuxhotel.de