what_is_chef.tex

\chapter{So, what is Chef?}

\begin{figure}[ht!]
  \center{\includegraphics[width=0.5\textwidth]{chef_logo}}
  \label{fig:chef_logo}
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\href{http://www.getchef.com/}{Chef} is a configuration management tool written in Ruby and Erlang. It uses a pure-Ruby, domain-specific language (DSL) for writing system configuration <<recipes>>. Chef is used to streamline the task of configuring and maintaining a company's servers, and can integrate with cloud-based platforms such as Rackspace and Amazon EC2 to automatically provision and configure new machines.

The user writes <<recipes>> that describe how Chef manages server applications (such as Apache, MySQL, or Hadoop) and how they are to be configured. These recipes describe a series of resources that should be in a particular state: packages that should be installed, services that should be running, or files that should be written. Chef makes sure each resource is properly configured and corrects any resources that are not in the desired state.

Traditionally, Chef is used to manage GNU/Linux but later versions support running on Windows as well.

\input{what_is_chef/principles}
\input{what_is_chef/benefits}

\section{Summary}

The key underlying principle of Chef is that you (the user) knows best about what your environment is, what it should do, and how it should be maintained. The chef-client is designed to not make assumptions about any of those things. Only the individuals on the ground — that's you and your team—understand the technical problems and what is required to solve them. Only your team can understand the human problems (skill levels, audit trails, and other internal issues) that are unique to your organization and whether any single technical solution is viable.

The idea that you know best about what should happen in your organization goes hand-in-hand with the notion that you still need help keeping it all running. It is rare that a single individual knows everything about a very complex problem, let alone knows all of the steps that may be required to solve them. The same is true with tools. Chef provides help with infrastructure management, and can help solve very complicated problems. Chef also has a large community of users who have a lot of experience solving a lot of very complex problems. That community can provide knowledge and support in areas that your organization may not have and (along with Chef) can help your organization solve any complex problem.