Middleware for handling vendor-specific $vendor-forwarded-proto -> x-forwarded-proto.

[ioquatix]

rack/rack#2187

[mpalmer]

It does what it says on the tin, and the test cases seem comprehensive, so 🎉.

I do wonder if SetXForwardedProtoHeader is the right name; it's not "setting" the header so much as using an alternate source. "Naming things" being, of course, one of the hard things, I don't want to block merge on it, but if AlternateXForwardedProtoHeader, for example, were to strike you as a suitable name, I wouldn't be against changing it.

[ioquatix]

I would like to change the name. I outlined my thoughts here: rack/rack#2089 (comment)

@tomharvey would you like to work on refining this a bit more?

[mpalmer]

A generic Foo-Forwarded-* -> Forwarded transmogrifier would probably be the platonic ideal -- I just didn't want to let the enemy be the perfect of the "well, I guess it's better than nothing" 😀 . I can't find any existing support for (eg) CloudFront-Viewer-Address anywhere in Rack, so presumably most people in this situation would want that header translated as well, at the very least.

[tomharvey]

As mentioned in rack/rack#2089 I've created a new PR here #193 and I can pick up the feedback from @mpalmer as I continue to work in that branch.