[minicoredumper] Fix some autotools related issues and add coredump rotation

[Juergen Borleis]

Hi John,

On Monday 11 March 2019 16:59:17 John Ogness wrote:
> On 2019-03-11, Juergen Borleis <jbe at pengutronix.de> wrote:
> > this set does some changes at the buildsystem level to have it
> > up-to-date.
>
> I will need some time to go through and verify all the autotools
> changes. But going through the patches, they look good.

Okay.

> > The last change adds a "rotation" feature to the 'minicoredumper' in
> > order to support long running systems where sometimes an application
> > crashes,
>
> Over the past few years I have received various requests for tasks like
> this. However, they all vary to some degree. I was thinking that rather
> than implementing all kinds of pre-/post-processing features, the
> minicoredumper should just support calling pre-/post-scripts. Then the
> rotation feature, for example, could be implemented as a pre-script.
>
> Until now my advice for people has always been to write a wrapper script
> that does what they want, then exec's minicoredumper. But if
> minicoredumper actually had a pre-/post-script feature, then the scripts
> could be recept-based (so that different scripts are called depending on
> what crashed).
>
> What are your thoughts on this? Do you agree that a pre-/post-script
> feature would be better than implementing things like rotation?

Hmm, the implementation in C is simple and small and IMHO thus follows the 
leading intentional "mini" in the "minicoredumper" name.
But sure, my rotate feature doesn't cover all use cases we can imagine.

On the other hand, adding script support adds more and more run-time 
dependencies to this small and powerful tool. If a system is under some 
pressure the smaller this tool is and the less dependencies it has, the 
more successfully it can work.

Maybe both features - script based pre/post handling for big machines 
and 'simple rotation' for small machines - would be useful. And one can 
select one out of these two features at compile time?

Regards,
Juergen