How to link Docker services across hosts?

Question

Docker allows servers from multiple containers to connect to each other via links and service discovery. However, from what I can see this service discovery is host-local. I wou

Answer 1

Weave is a new Docker virtual network technology that acts as a virtual ethernet switch over TCP/UDP - all you need is a Docker container running Weave on your host.

What's interesting here is

• Instead of links, use static IPs/hostnames in your virtual network
• Hosts don't need full connectivity, a mesh is formed based on what peers are available, and packets will be routed multi-hop to where they need to go

This leads to interesting scenarios like

• Create a virtual network across the WAN, none of the Docker containers will know or care what actual network they sit in
• Move your containers to different physical docker hosts, Weave will detect the peer accordingly

For example, there's an example guide on how to create a multi-node Cassandra cluster across your laptop and a few cloud (EC2) hosts with two commands per host. I launched a CoreOS cluster with AWS CloudFormation, installed weave on each in /home/core, plus my laptop vagrant docker VM, and got a cluster up in under an hour. My laptop is firewalled but Weave seemed to be okay with that, it just connects out to its EC2 peers.