Re: Trouble starting services on boot with s6-rc

["Laurent Bercot" <ska-supervision@skarnet.org>]

>Hoping this is the right place to ask for some help as I am very new to s6 and not well versed on any init system.

  s6-overlay questions are normally asked in the "Issues" section of the
s6-overlay GitHub repository, but since yours are really s6-rc 
questions,
it's fine :)  (even though the answers are related to s6-overlay!)


>I can see that my services are registered with s6-rc
>[Aug 19 18:43:04 root@s6 ~]# s6-rc-db list all | grep -e longrun_test -e sleeponstart
>sleeponstart
>longrun_test

  That proves your services are *in the database*, not that they're going
to get started. To make sure your services are started on boot, you
should also check that they're declared in the "user" bundle (that's
the bundle where users declare what services are part of the final
machine state, by s6-overlay policy).

$ s6-rc-db contents user | grep -e longrun_test -e sleeponstart

  But since they *are* started when you boot your container, it means
they're indeed declared there, so that's not the issue. The real issue
is here:

>root          34  0.0  0.0    192    52 pts/0    S+   18:53   0:00 /package/admin/s6-2.11.1.0/command/s6-sudoc -e -t 30000 -T 4999 -- up 3

  The "-T 4999" part means there's a 5 second timeout on running your
sleeponstart service. And since this service is waiting for 30 seconds
before succeeding, and 30 > 5... it means that it times out after 5
seconds and gets killed, so the transition fails, and longrun_test
(which depends on it) is never brought up.

  s6-overlay-specific section:

  - You should see all that happening in your container's logs - s6-rc
prints informative messages when something fails. Unless you have
changed the S6_VERBOSITY value from the default 2 to something lower.

  - The 5 seconds timeout likely comes from the fact that you have not
modified the S6_CMD_WAIT_FOR_SERVICES_MAXTIME value, which is 5000 by
default. As is written in both the README[1] and the migration guide[2] 
:P
If your real service needs it, you can disable the timeout by adding to
your Dockerfile:
ENV S6_CMD_WAIT_FOR_SERVICES_MAXTIME=0
or you can adjust it to a bigger value than 5000.

  Good luck,

--
  Laurent


[1]: https://github.com/just-containers/s6-overlay/blob/master/README.md
[2]: 
https://github.com/just-containers/s6-overlay/blob/master/MOVING-TO-V3.md