SRV service discovery support

[mattklein123]

Support SRV queries (used by Consul DNS, etc.) so that DNS can return IP/port combinations.

SRV is not supported by getaddrinfo_a so need to integrate with DNS library to make the query directly.

[mattklein123]

Note, a PR was started in #517 but it looks like it's not going to get finished. If anyone wants to pick it up please chime in here. cc @0x1997

[ludov04]

Any update on this?
The new service discovery feature on AWS ECS make use of SRV records. If envoy would support this, this would greatly simplify the use of envoy on ECS, no need no manage a consul cluster anymore.

Thanks :)!

[ChrisLahaye]

Any update on this?
The new service discovery feature on AWS ECS make use of SRV records. If envoy would support this, this would greatly simplify the use of envoy on ECS, no need no manage a consul cluster anymore.

Thanks :)!

Are you still using Consul as alternative?

[davidcpell]

@ludov04 @ChrisLahaye I'd also be interested to know!