We never ended up using this and it makes it much harder to reason about the listeners.
An explanation: for the moment I separated out all of the listeners in the struct, even though one should suffice, because when I did it that way first I was hitting some really weird and hard to find intermittent behavior where it seemed like the listeners were getting crossed. So I re-did it this way with each listener very explicitly referenced. I'm happy to make a follow-up PR that attempts to combine them all into a single listener without hitting the issues I did, if desired, but at least doing it via a separate PR means that it won't be something with removing the ALPN muxer that is at fault.
* feat(controller): New health service and server
This change also implements a new listener purpose, `ops`.
`ops` (short for operations) is a new listener purpose that is
responsible for serving Boundary's operations endpoints, like health
and possibly metrics.
At Startup: `ops` listeners get configured as late as possible to catch
any errors with the startup process;
At Shutdown: If the health endpoint has been set-up, we introduce a
configurable delay in the process. This is to enable the health endpoint
to report unhealthy for that amount of time. `ops` listeners are also
the last listeners to be shutdown.