Migrate scripts to Python 3

Summary

Python 2 is no longer supported and so container builds fail:

Collecting influxdb
  Downloading https://files.pythonhosted.org/packages/ef/02/da676b46a3c7b7387151554bd71a15d455ec512222f7f5171ae8607522aa/influxdb-5.2.3-py2.py3-none-any.whl (73kB)
Collecting libvirt-python
  Downloading https://files.pythonhosted.org/packages/cb/6e/72e1b6db7089068d3ef145e7af76bb9ffd94d20f3ed88e2ed66d6e0e4f8f/libvirt-python-6.0.0.tar.gz (196kB)
    Complete output from command python setup.py egg_info:
    libvirt-python requires Python 3.x to build

We really should migrate to Python 3.