Nowadays the customer faced issue that they can’t override proxy in yum.conf when they are deploying centos image.
After some investigation. I found out that below yaml is working ok.
Ubuntu Pastebin ( z_custom key )
I wanted to override this code which put by maas
If ordering by this way is working, I think they can modify anything in their image.
and It would be better if this can be documented if it is true.