A cookbook is the fundamental unit of configuration and policy distribution in Chef Infra.
A cookbook defines a scenario and contains everything that is required to support that scenario:
- Recipes that specify which Chef Infra built-in resources to use, as well as the order in which they are to be applied
- Attribute values, which allow environment-based configurations such as
- Custom Resources for extending Chef Infra beyond the built-in resources.
- Files and Templates for distributing information to systems.
- Custom Ohai Plugins for extending system configuration collection beyond the Ohai defaults.
metadata.rbfile, which describes the cookbook itself and any dependencies it may have.
The Chef Infra Language is based on Ruby, allowing you to utilize the power of Ruby when the built-in language doesn’t meet your needs out of the box. If you’d like to learn more about extending your Chef Infra code by using Ruby see our Ruby Guide for further information on Ruby functionality.
The Chef Infra Language is a comprehensive systems configuration language with resources and helpers for configuring operating systems. The language is primarily used in Chef Infra recipes and custom resources to tell the Chef Infra Client what action(s) to take to configure a system. The Chef Infra Language provides resources for system-level components such as packages, users, or firewalls, and it also includes helpers to allow you to make configuration decisions based on operating systems, clouds, virtualization hypervisors, and more.
Chef Infra Client runs a recipe only when instructed. When Chef Infra Client runs the same recipe more than once, the results will be the same system state each time. When a recipe is run against a system, but nothing has changed on either the system or in the recipe, Chef Infra Client will not change anything.
A cookbook is comprised of recipes and other optional components as files or directories.
A recipe is the most fundamental configuration element within the organization. A recipe:
|Attributes||attributes/||An attribute can be defined in a cookbook (or a recipe) and then used to
override the default settings on a node. When a cookbook is loaded
during a Chef Infra Client run, these attributes are compared to the
attributes that are already present on the node. Attributes that are
defined in attribute files are first loaded according to cookbook order.
For each cookbook, attributes in the |
|Files||files/||A file distribution is a specific type of resource that tells a cookbook how to distribute files, including by node, by platform, or by file version.|
|Libraries||libraries/||A library allows the use of arbitrary Ruby code in a cookbook, either as a way to extend the Chef Infra Client language or to implement a new class.|
|Custom Resources||resources/||A custom resource is an abstract approach for defining a set of actions and (for each action) a set of properties and validation parameters.|
|Templates||templates/||A template is a file written in markup language that uses Ruby statements to solve complex configuration scenarios.|
|Ohai Plugins||ohai/||Custom Ohai plugins can be written to load additional information about your nodes to be used in recipes. This requires Chef Infra Server 12.18.14 or later.|
|Metadata||metadata.rb||This file contains information about the cookbook such as the cookbook name, description, and version.|
Chef maintains a large collection of cookbooks. In addition, there are thousands of cookbooks created and maintained by the community:
|Cookbooks Maintained by Chef||Chef maintains a collection of cookbooks that are widely used by the community.|
|Cookbooks Maintained by Sous Chefs||Sous Chefs is a community organization that collaborates to maintain many of the most used Chef cookbooks.|
|Cookbooks Maintained by the Community||The community has authored thousands of cookbooks, ranging from niche cookbooks that are used by only a few organizations to popular cookbooks used by almost everyone.|
Generate a Cookbook
Use the chef generate cookbook subcommand to generate a cookbook.
A cookbook generated with
chef generate cookbook custom_web creates a cookbook named
custom_web with the directory structure:
. cookbooks - custom_web - recipes - default.rb - test - integration - default - default_test.rb - .gitignore - CHANGELOG.md - chefignore - kitchen.yml - LICENSE - metadata.rb - Policyfile.rb - README.md