Research registrator

[etoews]

After Research interlock:1.0.0 I felt like it was worthwhile to research other service discovery options.

[etoews]

It turns out these service discovery tools that were written before Docker overlay networking came about naturally need some time to catch up.

Some relevant issues:

• Add support for overlay network
• Using -internal with docker-consul registers internal ip of Consul container for all services
• Bad IP when using the new network feature
  • "registrator with the -internal flag uses the IPAddress from NetworkSettings.IPAddress. In docker 1.9 this was deprecated and the value is now only populated if you use the default docker bridge."
• Option to only register containers that have --env SERVICE_NAME defined (this would be just nice to have)

Some relevant PRs:

• Allow specification of desired docker network to registrator for internal IP registration
• Populate internal IP using NetworkSettings.Networks where available (this is essential and there's already an image kidibox/registrator out there with it)

Some good reads:

• Automatic scaling with Docker 1.9 and overlay network locally and in AWS by @SirIle
  • This is how I stumbled across the image kidibox/registrator
• Load Balancing with Docker Swarm by @botleg
  • Side steps the problem by publishing the app server ports publicly, which let

[etoews]

Considering Registrator has the same problems as Interlock with overlay networking, we're going to go with Interlock for now and contribute there, see ehazlett/interlock#91