Certain Linux distributions do not come with python3 by default

[NucciTheBoss]

Known distributions that do not come with python3 installed by default:

• Arch Linux
• Debian
• CentOS 8-Stream

A mechanism needs to be added where cleantest can install python3 before it tries to inject itself into the instance otherwise there is going to be a bloodbath.

Note: There may be other test environment instance bases that do not come with python3 installed by default. I will add the bases to the list as I stumble upon them in my testing.

[NucciTheBoss]

Can probably make sure that Python 3 is installed by using cloud-init, but that would require switching the LXD images over to the cloud variants rather than the default variants. Also, it needs to be determined if there are ARM64 versions of the cloud images or there are only AMD64 ones.

[NucciTheBoss]

CentOS 8 Stream was dropping due to upgrading cleantest to upgrading from Python 3.6 to Python 3.8. Decided that using an older, unsupported version of Python just to support some niche distributions was not worth it.

[NucciTheBoss]

Coincidentally, I did not need cloud-init to fix the missing Python issue. All I had to do was switch the images over to their cloud variants which have cloud-init preinstalled. Makes since cloud-init is written with Python. No Python, no cloud-init. I like how that works.

[NucciTheBoss]

This is fixed in the 0.5.0-dev branch so once those commits land I can close out this issue. The upcoming pull request is going to be a big one!