GEP: Backend Protocol Selection

[dprotaso]

/kind gep

This is an attempt to separate out the backend protocol selection from GEP-1282. This is similar to how TLS use-cases are being split out into GEP-1897

What would you like to be added:

The ability to express the protocols supported by backends.

Why this is needed:

Not all implementation support automatic protocol selection. Even in some cases protocols are disabled without an explicit opt-in (ie. websockets). Thus application developers need the ability specify the protocol of their applications.

[dprotaso]

/assign @dprotaso

[dprotaso]

For those following GEP PR is out - #1979

[shaneutt]

Since the GEP already exists and because it's a GEP it seems reasonable to consider this accepted:

/triage accepted

However, it doesn't seem clear to me that this is something we must sort out prior to GA (though I invite arguments to the contrary) so at least for now we wont consider this a blocker for GA and it will have a lower priority than GA-oriented work:

/priority backlog