> On Oct 15, 2018, at 16:17, Uoti Urpala <uoti.urp...@pp1.inet.fi> wrote: > > On Mon, 2018-10-15 at 15:09 -0700, Johannes Ernst wrote: >> I have several programs A, B and C that, while they are running, require >> memcached.service to be running. >> When none of A, B, or C is running, I want memcached.service to not run >> either. >> A, B and C should share the same memcached instance. >> >> How do I best express this? >> >> I was thinking I would have a foo@.service, which would be started by A, B >> and C as foo@A, foo@B, and foo@C right when they come up, and stopped before >> they quit. This foo@.service would have a dependency on memcached.service, >> but otherwise not do anything. > > Why this indirection through "foo" instead of direct dependencies? Are > A, B and C not systemd services, so you require "foo" as a placeholder > that reflects their dependencies?
Yes, they are something else than a systemd service, in my example simply long-running batch programs. >> 1. There isn’t a Type=Noop, so having an ExecStart=/bin/true might be my >> best option? > > I think a service with Type=oneshot and RemainAfterExit=true should > work with no ExecStart lines. "Service lacks both ExecStart= and ExecStop= setting. Refusing.” That presumably could be a .target but having a dummy exec is fine. >> 2. How do I get memcached.service to stop automatically? A Requires= seems >> to keep it running even after all foo@.service have gone away. > > Add StopWhenUnneeded=true to the configuration of the memcached > service. Ah. There’s always one more keyword somewhere :-) Thank you, Johannes. _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
