Re: [systemd-devel] dbus API for unit state change?
On Sun, Oct 6, 2013 at 3:10 PM, Lennart Poettering wrote: > So, yeah, if you respond to each UnitNew signal you get with a property > Get/GetAll call, then this will result in endless ping pong, which is > certainly not a good idea. > > What are you trying to do? Write some tool that tracks all units that > are loaded? Yes, I want to register services into a networked service registry. An example use case would be an HTTP load balancer that is service registry aware and adds machines to the load balancer based on certain unit files appearing/leaving. An alternative solution is making a user explicitly add a service-registry-notifier@.service to my-application.service.wants but I wanted to avoid making registration a special case. For example: https://gist.github.com/philips/6710008 Maybe there is a middle ground solution? Does it makes sense to send LoadState with UnitNew? I will have to look tomorrow because I think without that trying to do other things gets racy with transient units. Thanks, Brandon ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH 2/2] Run with a custom SMACK domain (label).
On Wed, Oct 02, 2013 at 11:12:09AM -0700, Auke Kok wrote: > Allows the systemd --system process to change its current > SMACK label to a predefined custom label (usually "system") > at boot time. > > This is needed to have a few system-generated folders and > sockets automatically be created with the right SMACK > label. Without that, processes either cannot communicate with > systemd or systemd fails to perform some actions. > --- Hi, the patches look OK. I dont' have a system with smack support at hand, but I tested them on Fedora, and didn't notice any adverse effects. I you've tested them with smack, then they should be applied, imo. Zbyszek ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] dbus API for unit state change?
On Fri, 04.10.13 17:19, Brandon Philips (bran...@ifup.co) wrote: > > Another dbus question: > > Is it expected that a UnitNew and UnitRemove are sent when I use > org.freedesktop.DBus.Properties.Get or GetAll? This also happens with > `systemctl status doesnt-exist.service` Yupp it kinda is. The logic behing this is that systemd minimizes the unit file descriptions it has loaded into memory. Basically, unit files are unloaded if they are not active and if no other unit that is loaded references them. Each time something is loaded or unloaded you get a UnitNew or UnitRemoved signal, to keep you updated what is currently in memory. Any unit request will implicitly load the units referenced by it, in order to make this scheme race-free for the client. > Here is an example of what I am seeing: > https://gist.github.com/philips/6834913/raw/5bd36998829ca44c25c3798afd3c77c147b1ba27/gistfile1.txt > > This isn't very nice because I need to explicitly guard against > getting into an infinite loop of looking up properties on non-existent > units. So, yeah, if you respond to each UnitNew signal you get with a property Get/GetAll call, then this will result in endless ping pong, which is certainly not a good idea. What are you trying to do? Write some tool that tracks all units that are loaded? Lennart -- Lennart Poettering - Red Hat, Inc. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
