rethinkdb-coreos-cluster

RethinkDB clustering made easy with CoreOS, etcd2 and Docker.

RethinkDB clustering lacks clear and simple discovery support. But CoreOS makes it really simple, by leveraging on the distributed keystore, etcd.

CoreOS uses etcd, a service running on each machine, to handle coordination between software running on the cluster. For a group of CoreOS machines to form a cluster, their etcd instances need to be connected.

A discovery service, https://discovery.etcd.io, is provided as a free service to help connect etcd instances together by storing a list of peer addresses, metadata and the initial size of the cluster under a unique address, known as the discovery URL. You can generate them very easily:

The discovery URL can be provided to each CoreOS machine via cloud-config, a minimal config tool that's designed to get a machine connected to the network and join the cluster.

This repository provides one cloud-config for you, but it will need some preparation in order to use a unique token for cluster discovery, as described above.

./setup

The output should be something like this:

$ ./setup
Retrieving discovery URL from discovery.etcd.io..
Discovery URL: [https://discovery.etcd.io/047a15e89b8d6c471df362c47f45525a]
Preparing cloud-config..
Done. Please use temp/rethinkdb.yaml cloud-config for provisioning your RethinkDB cluster nodes.

You should now have a valid cloud-config with a unique discovery URL at ./temp/rethinkdb.yaml. Use it for provisioning your nodes.

Notes

According to the CoreOS documentation, this cloud-config will work only for the providers detailed below.

The $private_ipv4 and $public_ipv4 substitution variables referenced in other documents are only supported on Amazon EC2, Google Compute Engine, OpenStack, Rackspace, DigitalOcean, and Vagrant.