On Thu, December 17, 2015 8:08 am, Mustafa Muhammad wrote:
On Thu, Dec 17, 2015 at 6:24 PM, Lennart Poettering
<mzerqung(a)0pointer.de>
wrote:
> On Thu, 17.12.15 10:02, Colin Walters (walters(a)verbum.org) wrote:
>
> > On Thu, Dec 17, 2015, at 08:28 AM, Neil Horman wrote:
> > >
> > > I would question why its necessecary to keep systemd out so
> ardently.
> If you
> > > build your container layers properly, you can effectively put
> systemd
> in a base
> > > container and layer other applications in child containers that
> inherit from it.
> >
> > If one is doing "micro" containers that only have typically one
> process
> in them,
> > having systemd managing it is unnecessary overhead.
>
> Can you give realistic examples for these? Can you explain what you
> are intend to run as PID 1 in them instead? What is cleaning up /tmp
> for those things? What is setting up the tmpfiles bits in /run for
> them, and so on?
>
The recommendation for docker containers is to only have one process, when
it dies, the whole container stops, this is how to manage a cluster and
know when something die.
The larger point is that -- despite best efforts -- there are still
paradigms where the init process doesn't need to be heavy or complex in a
system. Lightweight zombie processing and perhaps dispatching telinit
signals to something else, if that.
Modularized into distinctly-installed packages or not, there's no need for
systemd in that environment when something smaller will do for PID 1.
-jc