Some context for this patch. I would like to support a new preset model, which has the following properties:
- distribution shipped defaults are enabled - and are applied to each boot/upgrade - without overriding any user configuration In many ways it is very similar to existing functionality but not quite possible to achieve all of the above. Thus, I'm introducing a new optional functionality, new unit configuration directory, and new transient-preset configurations. On each boot, if TransientPreset=yes, presets from /usr/lib/systemd/system-preset-transient/*.preset are applied into configuration path /run/systemd/system-preset-transient/. An upgrade tool, sysadmin can repeat that action at appropriate points by also calling: systemctl --runtime preset-all. If distribution integrates usage of Transient Presets, it gains a few very nice properties. Fresh installations, much upgrades. User/admin modifications are preserved. And there is no additional logic required to maintain separation / diffs between system-defaults and user-modifications. At the moment distributions like Debian (where most things are enabled by default) maintain a complex state in /var/ which tracks which things were distro-enabled before/after the upgrade, as well as whether user/admin has disabled/enabled things before/after the upgrade and try hard to correctly reconcile the correct state for all units. However, with this patch, most of this segregation moves away. The "transient presets" concept was discussed at the systemd hackfest in Brussels. I hope this matches at least some expectations and things we agreed upon there, but face-to-face meetings have a high amount of details that get lost/misunderstood, so comments & questions & review are welcomed. I'm starting to integrate and use this concept already, and I'm hoping it's un-intrusive enough to be included upstream. The remaining part, which is not addressed in this patch series, yet, is the ability to override .wants/ symlink from a higher order configuration directory. That is if the following symlinks are present: /etc/systemd/system/foo.service.wants/bar.service -> /dev/null /usr/lib/systemd/system/foo.service.wants/bar.service -> ../bar.service There is no wants dependency added from foo.service -> bar.service. This bit is discussed in details and agreed upon on the mailing list. (Unwants thread has urls to the messages) Regards, Dimitri. Dimitri John Ledkov (1): Add support for transient presets, applied on every boot. man/systemd-system.conf.xml | 1 + src/core/main.c | 30 +++++++++++++++++++++++ src/core/system.conf | 1 + src/core/unit.c | 2 +- src/shared/install.c | 59 ++++++++++++++++++++++++++++++--------------- src/shared/install.h | 2 +- src/shared/path-lookup.c | 2 ++ 7 files changed, 76 insertions(+), 21 deletions(-) -- 2.1.0 _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
