[systemd-devel] Support for staged startup

[Alison Chaiken]

Marko Hoyer asks:
> I'd like to realize a staged startup with systemd which is mainly about:
> - starting up a static tree up to a final service
> - the only job of the final service is to kick off the start of an additional sub tree of units
> This kind of startup could be realized simply by adding an additional one shot service which executes: systemctl start xxx.target

Marko, one target can already be specified as "After" another.   If
B.target is present in one of the appropriate directories and
specifies

After=A.target

and all the services of the final sub-tree are symlinked in a
B.target.wants directory, doesn't the behavior you need result?   What
is  missing?    Of course, some of the units linked in B.target.wants
may already be started by the time A.target completes if they are part
of a earlier target or if they are needed by an earlier unit.   To
suppress that behavior, you'd have to edit the individual units.

I don't know of any use case for one unit to start another directly.
Is there one?

-- Alison

-- 
Alison Chaiken                           alison at she-devel.com
650-279-5600
http://{she-devel.com,exerciseforthereader.org}
Never underestimate the cleverness of advertisers, or mischief makers,
or criminals.  -- Don Norman