making Config configurable programmatically

[dbarrosop]

The idea is that I want to be able to do:

    brigade = Brigade(
        inventory=SimpleInventory("../hosts.yaml", "../groups.yaml"),
        dry_run=True,
        config=Config(raise_on_error=False),
    ) 

[ogenstad]

I like the idea of this. However, one potential issue I see is that people can set their own config keys in this way. That might cause a problem if we introduce that key as a "real" config value in a later release.

This could be handled by only allowing keys that exist in CONF.

Or perhaps allowing users to set their own config keys in this way by using a prefix like _ or similar. That way we could also load "private" keys if someone sent in a yaml files containing those to the config.

[dbarrosop]

However, one potential issue I see is that people can set their own config keys in this way. That might cause a problem if we introduce that key as a "real" config value in a later release.

Well, that's true for any class. They could do the same in any other class.

Or perhaps allowing users to set their own config keys in this way by using a prefix like _ or similar

I have been thinking about this and struggling with a decent solution. I think we shouldn't support what you suggest. We can provide "functions" to help configure an application (maybe even generalize the Config class so it can be reused) but what we are talking about is the object we pass to brigade so we shouldn't allow misuse. I'd suggest merging this as is and then discuss on a different PR a generic config class for users and a set of functions to let them configure their in a similar way as brigade can be configured.

In summary, I am merging this one and open an issue to track this new feature :)