TurnKey Linux's take on Ubuntu appliance development: KISS

[Pau Garcia i Quiles]

On Thu, Jan 7, 2010 at 12:29 PM, Steve Langasek
<steve.langasek at ubuntu.com> wrote:
> On Thu, Jan 07, 2010 at 01:31:44AM +0100, Pau Garcia i Quiles wrote:
>> What's different with tkpatch? Meaning, how would those prompts be
>> different if those conffiles were managed by tkpatch instead of dpkg?
>> Let's see:
>
>> * With Debian packages:
>>   1. I install Postfix using Ubuntu packages (say, Karmic packages)
>>   2. I install the postfix-appliance-config package, which modifies
>> dpkg-managed files in the Postfix packages
>>   3. Some months later, I upgrade Postfix to a new version using
>> Ubuntu packages (say, Lucid packages). I will be presented with some
>> prompts for stuff modified by the postfix-appliance-config package.
>
> The difference is that, per policy, there should be no such
> "postfix-appliance-config" package in Ubuntu that's modifying
> dpkg-registered conffiles.  Any configuration files that need to be
> programmatically altered by packages must first be unregistered from being
> conffiles.

What the Debian Policy probably aimed (and this is just my conjecture)
is at avoiding unexpected changes to conffiles. I. e. your package
should never touch my conffiles without warning me *beforehand* and
*very clearly*.

I'd say the Debian Policy was never meant for the "building a turn-key
appliance"-case. Maybe an amendment is needed:
"no package should modify conffiles installed by other packages" ->
"no package should modify conffiles installed by other packages,
except in the case the package which modifies other packages conffiles
states clearly it will do that in its description"

-- 
Pau Garcia i Quiles
http://www.elpauer.org
(Due to my workload, I may need 10 days to answer)