[Babel-users] [OpenWrt-Devel] [PATCH] babeld: use procd to start, stop, and respawn

[Gabriel Kerneis]

On Mon, Sep 08, 2014 at 10:54:29AM -0700, Dave Taht wrote:
> On Mon, Sep 8, 2014 at 6:10 AM, Baptiste Jonglez <bjonglez at illyse.org> wrote:
> >> Additionally adds a patch to the babeld source is to prevent the
> >> attempted recreation of a pidfile when babeld restarts uncleanly. This is
> >> also possible to do by passing -I '' on the command line, however procd
> >> interprets an empty argument terminating the list, and thus cannot supply
> >> empty arguments to programs it manages.
> 
> > Patching babeld itself is a workaround.  Why not tackle the root issue?
> > It seems that you encountered crashes in babeld, so that should be fixed,
> > instead of working around the crashes.  I did experience a few babeld
> > crashes myself, but never managed to find where they came from.
> 
> There lies the rub. If you have a deployed machine on a rooftop
> somewhere, it is better to restart the daemon automagically and log
> the action rather than attempt to debug it. Using procd to manage this
> stuff reduces the probability of a babel failure taking out a node by
> several orders of magnitude, and I strongly favor managing it this
> way. Certainly finding and fixing bugs so that it doesn't ever crash
> is a good option, but in the real world, nothing is perfect, and
> defense in depth is needed.

However, there is an elephant in the room here: "procd interprets an
empty argument terminating the list, and thus cannot supply empty
arguments to programs it manages".

Isn't there a way to fix *that* bug (or rather limitation) at least?

Best,
-- 
Gabriel