feat/strip-j2-jinja: implement rstrip for jinja2 input

[jkrzemin]

Added options "strip_postfix" and "stripped_postfix" to jinja2 input. This allows to remove output files extensions which is often the case for jinja2 template files (.j2).

Stripping is disabled by default and default value to strip is ".j2".

Closes issue #805

Proposed Changes

• add option "strip_postfix" to jinja2 input
• add option "stripped_postfix" to jinja2 input
• optional removal of file postfixes (i.e. extensions) on output files

[beddari]

Would it improve clarity a bit to change the variable names used here?

suffix_remove: true
suffix_list:
  - .j2

Additionally, we would like this feature to become a new default for the jinja2 input type, I added a comment about that to #805

[jkrzemin]

Fair point, this naming makes more sense. I'll update the PR tomorrow. Like we discussed on slack, I don't think it should be a default since it is a breaking change and quite a few can have workarounds for that. I think that the best approach would be to make it opt-in for now and a default in future.

[ademariag]

IMHO passing the list of suffix to strip might overcomplicate the problem, but curious to see what @ramaro thinks.

I'd stick to expect, if the flag is enabled, that all files have a .j2 extension, and remove it present.
what happens if the file doesn't have a j2 extension? we silently ignore it? we don't process it?

the one benefit of expecting the .j2 extension is that it would be easier to exclude from tests and linting files that are templates, which at the moment is not possible.

[jkrzemin]

Currently if file doesn't have an expected suffix (.j2 is a default, can be overridden) it will simply pass it over to rendering.

I don't think that skipping files without suffix is a good idea - you still have to provide them explicitly in compile step so I think that we can assume that if file ends up here, it should be rendered.

[ademariag]

you still have to provide them explicitly in compile step so I think that we can assume that if file ends up here, it should be rendered.

Kapitan also supports passing a directory, in which case you won't have explicitly all files declared in the inventory.

But yes I also think we can just make it compile anyway