When most people talk about automating infrastructure, they focus on things like consistency, scalability, and flexibility. While fine goals, we recently converted several projects to Chef for both systems AND application deployment, and found that, with a little work, these tools could also help you enable better software quality assurance, load modeling, and even improve resource allocation.
By sharing cookbooks across projects, we were able to standardize practices and eliminate arbitrary differences, while using parameterization to perfectly isolate the special needs of each project. This allowed us to transfer knowledge among staff much more quickly. Pulling in and parameterizing application state – database contents, website assets, uploaded content – allowed us to spin up new environments with as much or as little state as needed. Integrating with Vagrant and Jenkins, we were then able to use chef to treat the entire image – system and application – as a test fixture. As each engineer (ops or dev) has visibility into the whole stack, we can more easily move people between dev and ops, or between projects.