[rsyslog] desktop notifications from syslog

[Tom Metro]

david at lang.hm wrote:
> Tom Metro wrote:
>> Is there a recommended technique for displaying notifications on a GUI
>> desktop from syslog?
> 
> unfortunantly this is going to vary significantly based on which desktop 
> and distro you are using. 

I'm OK with that, as long as it can be broken into two pieces, with 
rsyslog providing some generic mechanism to provide access to the 
events, and a separate client that glues rsyslog to the particular GUI.

It seems that libnotify already covers most of the bases within the 
Linux universe. According to:
http://www.galago-project.org/specs/notification/

it implements a freedesktop.org standard. I know it is well supported by 
GNOME, and Googling shows at least some level of support for it in KDE, 
ROX and XFCE.


> one of the changes in Ubuntu 9.04 (just released) was a drastic change in 
> the notification daemon and how it works.

Thanks for the tip. I dug up this:
https://wiki.ubuntu.com/JauntyJackalope/TechnicalOverview#New%20style%20for%20notifications%20and%20notification%20preferences

which links to a video demonstrating the new notifications. What is 
unclear is whether this is just a new GUI layer over the same code, or 
at least something that is still protocol compatible with libnotify.

A forum posting led me to the notify-osd package:
https://launchpad.net/ubuntu/+source/notify-osd

which led me to the design specification:
https://wiki.ubuntu.com/NotifyOSD

According to that, the new system is compliant (or at least intended to 
be) with the freedesktop.org standard. The most notable difference is 
that these new "bubble" notifications are shown for a limited duration, 
as chosen by notify-osd, but if the client app. specifies infinite 
duration, it goes into a fall-back mode and shows a traditional alert 
box. In that regards, seems like a step backwards from 
notification-daemon, given that alert boxes are less visually appealing. 
Of course they might jazz up the alert boxes at a later time.

(In my prototype I've been using an infinite display duration, with the 
rationale that the kinds of messages being shown require user attention 
and should not be missed if the user isn't at the computer when they occur.)

The closest example they have in the spec is the kerneloops one:
https://wiki.ubuntu.com/NotifyOSD#kerneloops

and their plan is to migrate from using the (old style) notification 
bubble (looks like a system tray bubble, even though I don't think there 
is a corresponding tray icon) to a traditional alert box (again, seems 
like a step backwards, but I guess they're trying to increase 
consistency and reduce visual variety in notifications).

By using an infinite display duration via libnotify, according to their 
spec, it'll show an alert box, so this new usage will be consistent with 
the kerneloops use case.

(Their spec addresses the issue of avoiding accidental key presses that 
might dismiss a pop-up notification, and this was given as a rationale 
for bubbles not having any clickable buttons. But I didn't see how they 
addressed this problem for alert boxes.)

Having the notifications look nice would be good, but obviously the 
important thing is just getting them displayed. The bottom line looks 
like an app. that works with libnotify under Ubuntu 8.10 or earlier will 
continue to work with 9.04.

  -Tom