Shared timer application for synchronizing users working in intervals (e.g. 25 minutes).

Usage

Start session as user 'Franz':

./start_session.py

Check if user 'Franz' has a running session (and file a request if so):

./query.py Franz

List all sessions of all users:

./list.py

Setup

Prerequisite: Shared folder that all users have read/write access to.

For the GUI dialog:

apt-get install python3-tk

Some use case ideas

• User A starts a 30 min session at 2018-01-01T16:10

  • creates file "A-2018-01-01T16:40" containing the end time

• User B wants to know whether A has a session running currently

  • checks whether there is a file name with prefix 'A'
  • AND time stamp is still in the future

• User B wants to talk to A after his session

  • appends his user name to the current session file of user A
  • (or also a time stamp)
  • (or also some subject)

• User A finishes his current session

  • deletes his file
  • (or all of his files)

• User A wants to check if anyone has filed a 'talk request' for him

  • checks if his current session file contains anything

• User A walks over to User B due to a 'talk' request.

• User A wants to check who else is on the team, currently busy

  • lists all files and shows prefixes

• This works with

  • Dropbox
  • git
  • svn
  • Samba
  • local file system
  • scp?

Privacy Considerations

Prevent users from checking other's working state

• instead of a central repository, there's a daemon running on every user's machine.
• communication is via UDP broadcast or multicast
• It's impossible for User B to check whether A has a running session.
• User B wants to talk to A after his session:
  • B sends a broadcast addressed with A
    • includes his public key
  • 3 possible outcomes:
    • A is not logged in at all -> no reply
    • A has no session running at the moment -> broadcasts 'no session' encrypted with public key of B
    • A has a session running -> broadcasts 'end time' encrypted with public key of B