Review on Serf by Ronnie Polk

It's very easy to set up multiple servers with different roles in your cloud infrastructure.

You can control exactly which nodes run what role by changing config files without having to rely on puppet or other tools that may not be available everywhere or require you to have administrative access. We use this product at Red Hat because it allows us to easily spin-up new VMs within our AWS account while still allowing them to interact together (by passing secrets via environment variables). The UI could do with some work as clicking around isn't always the most intuitive way of doing things but once you get used to how everything works the tool makes sense! Easy provisioning of cloud infra using docker containers.