[AG-DEV] Location of AG config files

[Jason Bell]

Chris

Would this effect other Linux packages, such at Fedora?

Thanks,
Jason.

-----Original Message-----
From: Christoph Willing [mailto:c.willing at uq.edu.au] 
Sent: Tuesday, 9 September 2008 09:38 AM
To: Thomas D. Uram
Cc: AG DEV
Subject: [AG-DEV] Location of AG config files

Tom,

There is a problem with the Debian & Ubuntu AG packages. The revamped  
build tool mechanisms introduced early this year to accommodate  
multiple python versions on the same machine has an unfortunate side  
effect; anything under /etc is considered to be owned by a particular  
package and is removed completely during upgrades or reinstallations,  
regardless of whether another package may be using the same area.

In the case of the AG installation, a number of configuration files  
are kept in directories under /etc/AccessGrid3. In particular, /etc/ 
AccessGrid3/NodeServices normally contains the standard Audio & Video  
Services. However other packages may want to install services there  
too e.g. vpcscreen, aghdvic. Initial installation of these packages  
works OK but if the AG package is reinstalled or upgraded, the  
additional services are also removed.

(One way around this would be to create a single mega-package of AG &  
related service packages, but I feel it would be an unsatisfying, if  
not "wrong", solution)

This (new) unwanted behaviour occurs because of the special treatment  
given to files/directories under /etc, so an solution is to use a  
different location. I have done some testing using /usr/share/ 
AccessGrid3 instead of /etc/AccessGrid3 as a location for the config  
files. With this new location, any number of installations,  
reinstallations etc. of the AG  & related packages can now be  
performed without any interference to each other. Introducing the new  
location is trivial - a single line patch to the toolkit code itself,  
as well as a single line change in the packaging script of each  
affected package (accessgrid3.x, vpcscreen, aghdvic, etc.)


Since this is a Debian & Ubuntu specific problem, I don't expect that  
relocating /etc/AccessGrid3 needs to apply to all distributions  
(although it may be worth considering). However before I release any  
packages with the new file layout, do you have strong feelings about  
the proposed solution - or alternative solutions?

I've cc'd to AG-DEV in case someone more conversant with Debian/ 
Ubuntu Policies & packaging practices can offer advice; please chime  
in - I'm just a part-timer in this area and I'm keen to receive  
suggestions.



chris


Christoph Willing                        +617 3365 8350
QCIF Access Grid Manager
University of Queensland