Juju

Although the official documentation at the time of this writing says that Juju is not yet ready for production use, it is interesting and has enough potential to warrant an introduction. It is also likely that by the time the book is printed, Juju will be completely ready. Juju has been described as APT for the cloud. APT does an amazing job of installing, configuring, and starting complicated software stacks and services, but only as long as all of that happens on only one system. Juju extends this ability across multiple machines. Often, Linux servers are set up for similar tasks. Multiple physical machines may be deployed with similar configurations to work with one another in a network, perhaps for load distribution or redundancy to prevent downtime in the event of one failing or being overloaded. Systems administrators are masters at creating and orchestrating these networks. However, doing so traditionally requires setting up each machine individually, configuring its software settings and so on.

Tools have appeared over the years to help with this great task, such as Chef and Puppet; see Chapter 9 for a little more about these. Juju works to do for servers what package managers do for individual systems. It enables you to deploy services quickly and easily across multiple servers, simplifying the configuration process, and is particularly designed with cloud servers in mind. As with Chef’s recipes, those services are deployed using formulas that standardize communication, for example, and which may have been written by different people.