On Fri, Oct 31, 2014 at 2:27 PM, Rich Freeman <ri...@gentoo.org> wrote: > On Fri, Oct 31, 2014 at 1:34 PM, Tom H <tomh0...@gmail.com> wrote:
>> Is "After" really necessary as an option? I've never come across a >> service that uses "After" without a "Requires" or a Wants" but I've >> never taken the time to look. > > Hmm, I found After more common that Wants, but maybe I only look at > units that have problems. :) LOL. Which supports the thesis that "After" might not be a useful setting within a service unit. But it's just occured to me that target units use "After" without "Requires" or "Wants", for example network-online.target has "After=network.target". > I think the intent is to handle optional dependencies, but in practice > I don't know that it works well. It would almost be better to have > some kind of cluster config file that specifies all the actual > dependencies (possibly including cross-host) and have it spit out all > the unit dependencies automatically. That is a bit much to ask for > now, and probably a bit much for somebody who just wants their laptop > to launch kde after all their mounts are ready. Optional dependencies are handled by "Wants" like openrc's "use". IIUC you're referring to a BSD-like rc daemon config file. WOuldn't that have to be maintained by a sysadmin rather than by a package maintainer? > Specifying After vs Wants separately does make sense. Dependency > doesn't have to imply sequential. Do you have an example of a service that uses "After=" but doesn't need a "Requires=" or a "Wants="? I'm either being unimaginative or plain dumb, but I can't think of any. I wonder whether, if Lennart and co removed "After=" from service units and turned "Requires=" into the equivakent of the current "Requires=" and "After=" setup, someone would raise a storm over the change because it would've broken something.
