Status of Python 3 support for the agent

[andreas-doehler (Andreas)]

@mbunkus

CheckMK’s Docker check requires the Python-Docker module. This one isn’t available on Ubuntu 20.04. Additionally pip for Python 2 isn’t available on Ubuntu 20.04 either (only for Python 3), making installation rather cumbersome, especially for larger numbers of servers.

The Docker Python module is also available for Python 3. It is only available from 3.5 to 3.7.

mk_docker.py is working on one of my test systems under Win10 with python 3.7.7 and Docker with WSL2 backend.
I checked this with the mk_docker.py from dev version. The 1.6 version will not be changed until 1.7 if it not a bugfix i think.