[OpenAFS] Re: [OpenAFS-devel] Selecting a configuration file format for OpenAFS Services

[Jason Edgecombe]

Matt W. Benjamin wrote:
> Apologies for the previous blank message.
>
> I have some notes, but also a general thought.
>
> 1. I support the general concept of adding a flexible configuration file for openafs services.
>
> 2. I don't feel too strongly about what approach is chosen.  In addition to the selection criteria which Jeff proposed (composability, writeability), I think would prefer a scoped format with a richer syntax than what I recall of Windows INI files, but if that's what most folks want, great.
>
> a) Someone might look at libconfig, an LGPL library, which seems to have the required features.  I don't remember if it's API is elegant, though I used it once in 2001.
>
> 3. The one thing I feel more strongly about is this:  blocking new configuration options because we don't have a config file is not necessary to motivate people to support or to implement a config file.  When we have the config file, it's no force to move less common and more elaborate options in to the file.  "We need a config file" to reduce complexity, isn't a good argument for blocking new features.  Yes, early adopters of those features might find those features' configuration moved to a config file in a couple of months.  We will all deal.
>
> Regards,
>
> Matt
>
>
> ----- Original Message -----
> From: "Matt W. Benjamin" <matt@linuxbox.com>
> To: "Derrick Brashear" <shadow@gmail.com>
> Cc: "OpenAFS Devel" <openafs-devel@openafs.org>, "openafs" <openafs-info@openafs.org>, u+openafsdev-t07O@chalmers.se
> Sent: Saturday, May 16, 2009 10:59:07 AM GMT -05:00 US/Canada Eastern
> Subject: Re: [OpenAFS-devel] Selecting a configuration file format for OpenAFS  Services
>
>
> ----- Original Message -----
> From: "Derrick Brashear" <shadow@gmail.com>
> To: u+openafsdev-t07O@chalmers.se
> Cc: "OpenAFS Devel" <openafs-devel@openafs.org>, "openafs" <openafs-info@openafs.org>
> Sent: Saturday, May 16, 2009 10:07:12 AM GMT -05:00 US/Canada Eastern
> Subject: Re: [OpenAFS-devel] Selecting a configuration file format for OpenAFS  Services
>
> On Sat, May 16, 2009 at 9:48 AM,  <u+openafsdev-t07O@chalmers.se> wrote:
>   
>> Hello Derrick,
>>
>> On Sat, May 16, 2009 at 09:10:38AM -0400, Derrick Brashear wrote:
>>     
>>> Consider the case which pushed us here. You have an array of numbers.
>>> It's a set of timeout values, which apply when you have between a
>>> certain number of callers.
>>>
>>> You can, of course, just pass an argument which is a comma separated
>>> list of timeouts. What do they mean? Well, you don't need to pass
>>> those numbers, so, well, just make sure you order things right.
>>>
>>> But wait. What happens if you want to also make the ranges the
>>> timeouts apply in tunable? Do you now pass 2 lists, one for the bucket
>>> ranges and one for the timeouts, or a set of pairs? How do you
>>> delineate the pairs?
>>>       
>> Whatever is the challenge, it is about formulating some information
>> as text, either in a configuration file or on the command line.
>>     
I'm not set on the windows INI format, it was just the first suggestion 
and a commonly-used format. Some type of "key = value" format would be 
nice, but it should handle complex options.

Jason