replace the plugin command line protocol with plugin.yaml and environment variables about peru HOT 4 CLOSED

I'm still a tad wary of this approach. If we export variables from peru, then won't we need to worry about cleaning that state (i.e., flush/write/unset all relevant variables) before each call to a plugin? It could be easy to miss something. Will this work equally well on Windows as it does on Linux?

I totally agree that validation really ought not live in plugins; they should trust that peru has correctly processed and scrubbed their parameters, and metadata in plugin.yaml should facilitate that.

from peru.

I guess subprocess accepts a dict of environment variables, so this should fine.

from peru.

Right. Also I think we want the subprocess to inherit random variables from the parent, in case there are global hacks ($LD_PRELOAD magic) that should apply to the plugin as well as the parent. But it might make sense to scrub the variables that we know are immediately relevant, like anything starting with our PERU_FIELD_ prefix or whatever it ends up being.

from peru.

Here's a diff for this.

from peru.