Re: Incompatibilities between runit and s6?

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

>Has anyone tabulated technical differences between runit and s6? I'm
>considering migrating some systems which use runit to supervise some of
>their services (systemd the others - they're CentOS based). I am 
>wondering
>whether I can write a wrapper caled "sv" which calls s6-svc with the
>appropriate argument rewriting, to avoid needing to find and modify 
>many
>scripts. Has anyone written such an 'sv' command already?

  I'm not aware of such a command, but s6-svc supports everything sv
does, so writing such a script should not be hard. The only difficulty
is if the service uses a ./check file, which "sv start" supports
natively but s6-svc does not, so the wrapper would need to perform
the ./check polling itself; but the best thing to do in this case
is to rewrite the run script to use s6-notifyoncheck, so the check
automatically uses the s6 readiness notification framework.


>If you are a systemd user, chances are you do not need s6.
>
>Really? So all the criticism of systemd is bunkum?

  :) I need to update this page.
  What this means is that systemd does provide a supervision
infrastructure, so for people stuck with systemd, it's okay to use what
their system provides, and s6 is redundant there. This does not mean
that all my systemd criticism is invalid.

  Also, admittedly, I simply did not want to read the systemd unit file
documentation to understand how to start a s6 supervision tree from
systemd. I will do the effort and come up with a small unit file
suitable for this.

--
  Laurent