refactor: underscore variable prefix should be reserved...

[gardar]

...for internal variables that are not user configurable

While it's not specified in any standard that I'm aware of, it's common that variables that are used internally in a role are prefixed with a underscore.

These variables were once not user configurable, so it makes sense that they were prefixed in the past, but I don't see any reason to keep them that way.

[SuperQ]

We had an opinion that these vars were not supposed to be used by users. They used to be internal only. @paulfantom What do you think?

[gardar]

We had an opinion that these vars were not supposed to be used by users. They used to be internal only. @paulfantom What do you think?

Then they should be placed in vars/ and not defaults/
Looking at cloudalchemy repos I see that initially they were, but then got moved to defaults to allow users to overwrite them.
With that being said, I don't see any downsides of having them overwritten by users myself.

[paulfantom]

The initial idea was to structure variables following a pattern known from python. Initially, those variables were placed in vars/. However, over time, people started using them and variables were moved into defaults/ while keeping naming to preserve compatibility. Since we now moved the role to a different place and those variables are now meant to be overridden when needed I don't see any reason to keep prefixing them with underscores.