Edit 2015-01-07: Updated article to reflect changes in swarm. Thanks Rael! Docker Swarm was announced at the first European DockerCon. Swarm is a pluggable cluster manager with a simple scheduler. It’s currently not super easy to set up, so here is how I did it. Background The swarm executable discovers hosts by reading entries from the discovery url, discovery-stage.hub.docker.com/v1/clusters/TOKEN. Sample output: ["128.199.36.196:2375","128.199.50.146:2375","128.199.32.159:2375"] As you can see, this is just a list of IP/port combinations.

Jeff Lindsay wrote about “Consul Service Discovery with Docker” and Automatic Docker Service Announcement with Registrator. Using Docker’s event stream is an elegant solution to finding out which containers are running on a particular host. Despite Jeff’s documentation and videos, I couldn’t get Consul to serve up the correct locations of my services. Here is a description of what I did to get a service discovering cluster to run on Digital Ocean.

I’ve been trying out Dropwizard the last couple of months and it’s been very nice. There are many, many frameworks to choose from in Java country, so it comes as a relief to have a bunch of them chosen for me. Dropwizard glues Jersey, Jetty, Jackson and more together. The end result is a reduction in boiler plate code and complexity. Great for micro services. I am going to write a couple of posts about Dropwizard.