notify-broadcast 0.0.4

Broadcast version of notify-send to allow root processes to send a notification to all users with an active DBUS session

notify-broadcast

This program was developed because I run a number of cron jobs as root that I would like to be able to send notifications to the GUI User

notify-send only functions if run by the same user running the graphical session.

I created notify-broadcast to effectively take the same parameters as notify-send but that could be executed by the root user.

The application searches for all active DBUS Notification sessions, and sends the notification to all currently attached users.

Installation

When complete, should be:

pip install notify-broadcast

Seek information elsewhere about installing in a virtual environment

The install should pull in all dependencies. At present these are:

• colorlog: https://github.com/borntyping/python-colorlog/
• dasbus: https://github.com/dasbus-project/dasbus
• psutil: https://github.com/giampaolo/psutil
• PyGObject: https://pygobject.gnome.org

Usage

# notify-broadcast --help
usage: notify-broadcast [--help] [-a APP_NAME] [-i ICON] [-t EXPIRE_TIME] [-h TYPE:NAME:VALUE] [-c TYPE] [-u {low,normal,critical}] [-A NAME=VALUE] 
                        [-r REPLACE_ID] [-p] [-e HINT] [-L] [-R] [--log-level {DEBUG,INFO,WARNING,ERROR,CRITICAL}] [--global-log-level {DEBUG,INFO,WARNING,ERROR,CRITICAL}]
                        summary body

Notify Broadcast Send a Broadcast DBUS notification to all users

positional arguments:
  summary               Notification summary - used as heading for notification
  body                  Notification detail - primary notification text

options:
  --help                show this help message and exit
  -a APP_NAME, --app-name APP_NAME
                        Specifies the app name for the notification
  -i ICON, --icon ICON  Specifies an icon filename or stock icon to display. (default: dialog-information)
  -t EXPIRE_TIME, --expire-time EXPIRE_TIME
                        The duration, in milliseconds, for the notification to appear on screen. Value of 0 means no expiry, while -1 uses the server default 
                        expiry. (default: -1)
  -h TYPE:NAME:VALUE, --hint TYPE:NAME:VALUE
                        Notification hints to pass to server (e.g., int:urgency:2)
  -c TYPE, --category TYPE
                        Specifies the notification category.
  -u {low,normal,critical}, --urgency {low,normal,critical}
                        Specifies the urgency level (low, normal, critical).
  -A NAME=VALUE, --action NAME=VALUE
                        Specifies the actions to display to the user. Implies --wait to wait for user input. May be set multiple times. The NAME of the action
                        is output to stdout. If NAME is not specified, the numerical index of the option is used (starting with 1).
  -r REPLACE_ID, --replace-id REPLACE_ID
                        The ID of the notification to replace.
  -p, --print-id        Print the notification ID.
  -e HINT, --transient HINT
                        Show a transient notification. Transient notifications by-pass the server's persistence capability, if any. And so it won't be preserved
                        until the user acknowledges it.
  -L, --local           Send notification to all TTY local sessions
  -R, --remote          Send notification to all TTY remote(ssh) sessions
 
  --log-level {DEBUG,INFO,WARNING,ERROR,CRITICAL}
                        Set the logging level for the core application.
  --global-log-level {DEBUG,INFO,WARNING,ERROR,CRITICAL}
                        Set the global logging level (includes third-party libraries).

NOTE: For more support on these parameters, see notify-send man pages

Examples

Some examples of how to use notify-broadcast are listed below. These are by no means exhaustive:

notify-broadcast -a Daily-backup -t 0 -i dialog-information.png "Backup completed without error" ""

Display a notification that the backup has completed without error:

• Display an information icon
• A timeout of 0 signifies that the notification will display until the user clears it
• Message contains a summary, but no body

notify-broadcast -a Remote-rsync -t 6000 -i dialog-warning.png "Remote host not currently on the network" ""

Display a notification that the remote host is not available:

• Display a warning icon
• A timeout of 6000 signifies that the notification will display for six seconds before clearing
• Message contains a summary, but no body

notify-broadcast -a Daily-backup -t 0 -i dialog-error.png "Error running backup, please consult logs" ""

Display a notification that the backup has completed without error:

• Display an error icon
• A timeout of 0 signifies that the notification will display until the user clears it
• Message contains a summary, but no body

notify-broadcast -a "Disk Monitor" -h string:desktop-entry:org.kde.kinfocenter-i drive-harddisk "Disk" "SMART warning"

Display a notification that a disk has encountered a SMART error:

• Display an disk icon
• No timeout signifies that the notification will display for the system default duration

Comments

I am aware of a number of potential shortcomings that may impact broader distribution, as well as some points about why things were coded this way, details listed below

Finding DBUS Path via environment variables instead of /run/user/{uid}/bus

The code searches for the DBUS_SESSION_BUS_ADDRESS environment variable in a running program, while many online examples suggest searching /run/user/{uid}/bus

My system (Gentoo) does not place the DBUS sockets in that location, so searching the environment variables allows this to work regardless of the location of the socket.

Program is hard-coded to KDE

As per the previous point, to search the environment variables, it means finding a running application that has the environment variables set. This means that we need to know the application name to search for.

Hence, the program currently looks for running instances of kwin_wayland or kwin_x11 depending on the current session type.

This works for me as I use KDE, I don't like Gnome or other environments.

However, I realise this means that this will not work everywhere. Some chat online suggests looking for dbus-launch, however the environment for this process does not appear to contain the DBUS_SESSION_BUS_ADDRESS environment variable.

I would like to support alternate desktops, but I do not have the will to test and develop a solution. I am happy to take comments/suggestions on how to detect across multiple platforms.

Some of the Options are Useless for Broadcast application

As a broadcast application, this really makes sense as a 1) send a message; and 2) do not wait for replies scenario

1. --print-id makes no sense if sending multiple notifications
2. --replace-id make no sense if we are just blasting information to everyone
3. --action display buttons to the user and return values to the program. This is generally useless for this application

Running as non-root

A non-root user will not be able to post notifications to other users in either case. The application currently just prints warnings about being unable to access the environment and does nothing else.

It might be better to abort early if the user does not have permissions, but a system could allow multiple users the requisite permissions, so it is hard to manage this properly.