To code this program is for monitoring users' operations. Citris system brings Session Recording feature for Windows VDA, while not for Linux VDA. This is why I code this.

1. set suitable parameters in config.py;
2. update the ExecStart item as appropriate in SessionRecording.service;
3. run the following commands;

   sudo cp SessionRecording.service /lib/systemd/system/
   sudo systemctl daemon-reload
   sudo systemctl enable SessionRecording.service
   sudo systemctl start SessionRecording.service
   

1. The subprocess should be terminated/killed before the main process, otherwise the recorded video will not be playable. To achieve this, the following steps are applied:
   1. KillMode=process
   2. python code handles the SIGTERM gracefully
2. This repository should work with Citrix system, as ctxqsession is used to detect whether a GNOME session is active for a user.

1. Cannot track the change of resolutions. If the resolution is getting bigger when recording, the smaller window width by height is still in force, till the next recording period.