Google import

[htuch]

There are a number of things we need to ensure we can cleanly import Nighthawk into Google:

• service_main.cc needs to be able to handle IPv6 addresses. Its test, service_main_test.cc, should work with TestEnvironment::getIpVersionsForTest.
• service_test.cc and process_test.cc also need to consume from TestEnvironment::getIpVersionsForTest when forming loopback addresses.
• We need to switch Envoy import paths from overlay to external/envoy based and structurally enforce this.
• We need to eliminate the race being fixed in Service: address back to back execution race #118

[oschaaf]

I have been looking getting the include path overlay fixed.
There now is a candidate script to test for this: #122, but unfortunately updating the include paths as planned causes the build to fail.

[oschaaf]

status update:

• the fix for the observed race in the service is in review, pending discussion.
• maybe we should brainstorm on slack to see if we can come up with a plan B for disambiguating the Envoy include paths; the script to check for what we do not want to see is implemented, but actually updating the include paths doesn't seem to work for me (see the comment above).
• I'll look into getting the ipv6 handling sorted tomorrow.