Support HTTP health check

[FlorentinDUBOIS]

Hey :wave:,

A feature that could be great is to implements a http health check.

[Geal]

For sozu or for the backends? When I brought it up, that was instead supposed to be handled by an internal project at Clever Cloud, I don't remember its name though

[FlorentinDUBOIS]

Hey @Geal ! The idea is to implements a more sophisticated health check than the tcp one that already exists like haproxy does or others :)