add a --file flag to use a different chartpress.yaml

[rokroskar]

Proposed change

In projects involving more than one chart, it would be useful to have a --file flag such that a specific chartpress.yaml file could be targeted, e.g.

chartpress --file another-chartpress.yaml

Alternative options

This behavior can be achieved by separating out charts via the directory structure and running chartpress in subdirectories, but this is sub-optimal, tedious and error-prone.

Who would use this feature?

Anyone building multiple charts in a single repo that don't all need to be built/packaged at the same cadence.

[manics]

This is very similar to #118
Do you mind adding your suggestion on that issue instead and we can consider them together?

[rokroskar]

Thanks for reminding me about that issue! They seem to be addressing pretty different things though, I'm not sure they should be wrapped into one. #118 is about relative path handling after the chartpress.yaml file has already been parsed; this request is simply to allow one to specify an alternative chartpress.yaml. But maybe you have a solution in mind for #118 that makes this request here moot?

[rokroskar]

Actually, it looks like #118 has been fixed by #161 🎉

At least I no longer get an error trying to publish a chart that has the chartpress.yaml file at the root of the repo. 😆