tmux_env.py

When weechat runs simply in a terminal, weechat and its scripts inherit the parent environment variables. This allows scripts such as notify.py to access variables such as DBUS_SESSION_BUS_ADDRESS so they can interact with the desktop.

The problem of running weechat directly in a terminal is that you can't access it remotely with ssh, and it's not persistent if you log out and back in. Therefore it's common to run weechat inside screen or tmux so you can freely disconnect and reconnect.

One advantage of this setup is that you can manage your presence indication (awayness) with the screen_away.py script, which works just as well for tmux as for screen.

However the setup becomes problematic when your weechat scripts rely on environment variables. For example notify.py relies on DBUS_SESSION_BUS_ADDRESS for sending notifications to the screen. If this variable is missing or stale, then notifications will stop working.

Tmux provides a solution to this problem by providing access to the client environment variables, and propagating them to any new windows or panes instantiated after the client connects. Existing processes don't automatically get the updates, though, and that's where tmux_env.py (this script) bridges the gap by occasionally querying tmux and propagating environment changes into the tmux process, including the script interpreters.

What this means is that you can disconnect your ssh session and reconnect on your desktop, and the proper values of DBUS_SESSION_BUS_ADDRESS will appear in the weechat process environment, and therefore notify.py will be able to provide desktop notifications.

How to use

1. Install this script and notify.py

2. Configure tmux to update DBUS_SESSION_BUS_ADDRESS in .tmux.conf

   set-option -g update-environment 'DISPLAY SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID SSH_CONNECTION WINDOWID XAUTHORITY DBUS_SESSION_BUS_ADDRESS'
   

3. When you disconnect tmux and connect from somewhere else, you should see messages like this in weechat:

   tmux_env: add DBUS_SESSION_BUS_ADDRESS=u'unix:abstract=/tmp/dbus-K7Sk2maQI7,guid=e41a4322998f0ec0b937d5ef525ae11d' (was None)
   tmux_env: add DISPLAY=u':0' (was None)
   tmux_env: add SSH_AGENT_PID=u'1707' (was None)
   tmux_env: add SSH_ASKPASS=u'/usr/bin/ksshaskpass' (was u'/usr/libexec/openssh/gnome-ssh-askpass')
   tmux_env: add SSH_AUTH_SOCK=u'/tmp/ssh-6DDLwlmL8Uvs/agent.1547' (was None)
   tmux_env: remove SSH_CONNECTION (was u'172.20.0.4 38969 172.20.0.11 22')
   tmux_env: add WINDOWID=u'73401727' (was None)
   tmux_env: add XAUTHORITY=u'/tmp/kde-aronGPPXUt/xauth-10208-_0' (was None)