[gentoo-user] Openrc - where to register services for discovery

[Damo Brisbane]

I'd like to add hooks into an openrc startup script for sidecar
<http://ispyker.blogspot.com.au/2014/08/a-netflixoss-sidecar-in-support-of-non.html>
 type functionality, ie service discovery registration, but not exactly
sure the best way to do it. The problem seems to happen often enough that
i'd welcome some feedback on it. Preferably openrc, but s6 experience
appreciated. For example;

To add service discovery to the starting of some init.d service, eg lets
say a docker container, the container starts every time as a result of
running */etc/init.d/docker start*, and as a consequence of being created
with:

--restart=always

With above flag, the container will automatically start as part of the
standard docker init script, "/etc/init.d/docker start". But in my case,
the container does not natively register itself with consul (or could be
any other service discovery system). I know that I can run another
container to do the job of registering the container into the service
discovery system, but interested in any alternative *within the init
system*, ie using openrc script?

Might it as a *post-hook*, or as an extra file in some *conf.d* place? I
could hack together something, ie using a piece of code like "curl
.../register/myservice", but prefer to hear other peoples
experience/knowledge on how/where this may be done.
Cheers