Docker and service clusters

However, the one issue that we haven't really seen any answers for is how to allow clustered services to connect to each other correctly.

I think you're talking about HA/replicated/sharded apps here.

At the moment, in kubernetes, you can accomplish this by making an api call listing all the "endpoints" of the service; that will tell you where your peers are running.

We'd eventually like to support the use case you describe in a more first-class manner.

I filed https://github.com/GoogleCloudPlatform/kubernetes/issues/3419 to maybe get something more standardized started here.

I also wanted to setup an ElasticSearch cluster using Mesos/Marathon. As the existing "solutions" either were merely undocumented, or not working/outdated, I set up my own container.

If you like, have a look at https://github.com/tobilg/docker-elasticsearch-marathon

If you have a running Marathon installation (I use v0.8.1), then setting up an ElasticSearch cluster should be a matter of a few minutes.

UPDATE:

The container now uses Elasticsearch v1.5.2 and is able to run on the latest Marathon v0.8.2.

As for Kubernetes, it currently does require kube-controllers-manager to start with --machines argument given a list of minion IPs or hostnames.