Re: Overriding conf file with symlink under /etc considered harmful
First, I need a bit more clarification/confirmation that my understanding of
the challenge we're facing is correct, and then I'd like to see any prior
discussion & documentation (in the wiki?) we have on these issues (or help
write it if it doesn't exist yet).
On Sat, Apr 10, 2004 at 02:45:19PM +0200, Free Ekanayaka wrote:
> Well, maybe a CDD configuration package should be not considered in
> the same way as ordinary packages.
> I think will all agree that one of the main goals of a CDD, a part
> from barely installing a specific subset of packages, is to provide a
> properly tuned configuration for such subset.
> IMHO the two best strategies for this porpoise are:
> 1) feed the debconf database with custom values and then run
> dpkg-reconfigure --all
In prior discussions, is this what has been referred to as "pre-seeding"?
What are the arguments to date for/against this?
> 2) use cfengine to directly tune or create configuration files
> AFAIK these two methods were both introduced by Skolelinux.
> The second one is needed where the first can't deal, and even though
> CDDs developers should cooperate with the maintainers wherever is
> possible to introduce or improve the debconf support for a given
> package, my opinion is that there will be always cases which can't be
> cleanly handled with the first strategy.
Fair enough, but as much as possible, we try approach #1?
> A simple real life example from DeMuDi: I have to turn on the kernel
> lowlatency flag at boot time, and the best way to do it is by editing
> /etc/sysctl.conf adding a single line (kernel.lowlatency = 1).
> The sysctl.conf conffile belongs to the procps package, but of course
> introducing the debconf support for all possible kernel variables it's
> not feasible, so that I ended up using the cfengine strategy.
I see. I can't think of any decent alternative, either. I'd like to see
the prior discussion on this too, for reference.
> IMHO if someone wants to install a CDD, it means that he/she wants to
> have a pre-canned working system, which hopefully automatically
> configures itself.
> Thus when installing the CCD configuration package
> (e.g. debian-edu-config, debian-med-config, demudi-confg, etc.), the
> default answer to the question "do you want to modify this other
> package's conf file?" should be "yes".
> I don't know if understand correctly, but AFAIK when a new version of
> package provides a new version for one of its conffiles *and* the
> previously installed version of such confile has been modified, then
> dpkg *do* stop asking if you want to keep the locally modified version
> or replace it with the new one.
Surely you mean only in the symlink case being discussed? When a package
provides a new conf file and the old has been modified, dpkg will normally
prompt for whether you want to keep/replace the old. But what I've been
hearing earlier in this thread is that if the admin makes the conf file a
symlink to another conf file instead of merely modifying the conf file, then
this mechanism breaks.
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