The user writes "recipes" that describe how Chef manages server applications and utilities 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. These various resources can be configured to specific versions of software to run and can ensure that software is installed in the correct order based on dependencies. Chef makes sure each resource is properly configured and corrects any resources that are not in the desired state. Chef can run inclient/server mode, or in a standalone configuration named "chef-solo". In client/server mode, the Chef client sends various attributes about the node to the Chef server. The server uses Elasticsearch to index these attributes and provides an API for clients to query this information. Chef recipes can query these attributes and use the resulting data to help configure the node. Traditionally, Chef was used to manage Linux but later versions support Microsoft Windows as well. It is one of the major configuration management systems on Linux, along with CFEngine, Ansible and Puppet. More than a configuration management tool, Chef, along with Puppet and Ansible, is one of the industry's most notable Infrastructure as Code tools.
History
Chef was created by Adam Jacob as a tool for his consulting company, whose business model was to build end-to-end server/deployment tools. Jacob showed Chef to Jesse Robbins, who saw its potential after running operations at Amazon. They founded a new company with Barry Steinglass, Nathen Haneysmith, and Joshua Timberman to turn Chef into a product. The project was originally named "marionette", but the word was too long and cumbersome to type; the "recipe" format that the modules were prepared in led to the project being renamed "Chef". In February 2013, Opscode released version 11 of Chef. Changes in this release included a complete rewrite of the core API server in Erlang. On April 2, 2019, the company announced that all their products are now open source under the Apache 2.0 license.
Platform support
Chef is supported on multiple platforms according to a supported platforms matrix for client and server products. Major platform support for clients includes AIX, RHEL/CentOS, FreeBSD, OS X, Solaris, Microsoft Windows and Ubuntu. Additional client platforms include Arch Linux, Debian and Fedora. Chef Server is supported on RHEL/CentOS, Oracle Linux, Oracle Cloud and Ubuntu.
