Amazon AWS doesn't allow ElastiCache/Redis instances to be accessible outside of EC2 instances (outside as in, from my laptop). So for dev purposes, this means my docker containers need to reference the redis instance running on my local Mac.
But how do I map the redis server running on 6379 on my localhost into my boot2docker container? I somehow need to tell boot2docker to route some domain like my_real_localhost to 127.0.0.1 outside my VM.
From the point of view of a container running at Amazon (or inside Boot2Docker), it just needs to know an IP address of your Mac that it can connect to via any NAT routers and firewalls you are running, to port 6379 there.