This document provides an overview of Chef, a configuration management tool. It discusses how Chef works using a client-server model to configure nodes according to their run lists and roles. Cookbooks contain recipes that specify resources to configure nodes. Chef helps ensure consistency across environments like development, testing, and production.

1. Chef, Devops, and You Image from http://dev2ops.org/blog/2010/2/22/what-is-devops.html Bryan W. Berry, 18 November 2011

2. Who am I? Linux Geek for 7 years Python, Ruby coder Played with a lot of different configuration management tools and techniques

3. We need a new way to work Infrastructure needs to be Repeatable Testable Scalable No Snowflakes!

4. Devops? Agile Development Practices applied to infrastructure New tooling to automate infrastructure Testing, testing, testing

5. Infrastructure as Code http://www.flickr.com/photos/wonderlane/2306082998/

6. Chef is . . . A library for Configuration Management A Configuration Management System A Systems Integration Platform An API for your entire infrastructure Open-source!

7. How Chef works Chef Server PROD QA DEV Workstation VM Cookbooks Data Bags Attributes

8. DEV, QA, PROD Servers Supposed to have the same configuration Is this humanly possible without Chef? I don’t think so PROD QA DEV == ==

9. Chef client runs on each Server They talk to the Chef Server Chef can also run without a server, chef-solo

10. We call each system you configure a Node

12. Attributes are Searchable $ knife search node ‘jdk_version:1.7’ # returns list of nodes with jdk 1.7 search(:node, ‘java_version:1.7’)

13. Nodes have run_list “ run_list”: { “ recipe[java]”, “ recipe[jboss]”, “ role[internal]” }

14. Nodes have Roles Roles describe what a node should be

15. Roles are Searchable $ knife search role ‘max_children:50’ search(:role, ‘max_children:50’)

16. Roles have a run_list What roles or recipes to apply in order

17. Chef manages resources on nodes Resources are specified in recipes, recipes are stored in cookbooks A node’s run_list specifies which recipes (and thus resources) are applied

19. Client / Server Chef Server PROD QA DEV Nodes Nodes report their attributes to the Chef-server with the ‘ Node’ object attributes Chef Repository

20. Chef Server PROD QA DEV Nodes Server applies roles and sends run_list, roles, and all cookbooks back to clients run_list, roles, cookbooks Chef Repository

21. Skinny Server, Fat Clients No “builds” are done on the server A Node configures itself based on its run_list and the downloaded cookbooks

22. Back to Recipes!

25. Ruby, baby! Chef configuration written in pure ruby Devops == Ruby If you also learn Ruby, it will be helpful but is not required If you are really curious why devops == Ruby, you read more here http://devopsanywhere.blogspot.com/2011/09/how-ruby-is-beating-python-in-battle.html

26. Cookbooks are packages for Recipes

27. Cookbook Components Attributes Recipes Metadata Assets (files/templates)

28. Sharing is beautiful 200+ high-quality cookbooks on community.opscode.com and growing all the time Easy to customize existing cookbooks Chef’s real value is this collection of cookbooks

29. Data Bags Data Bags are arbitrary stores of globally available JSON data Think of them as global variables/data sctructures for your infrastructure

30. Data Bags have Items Data bag users/john { "comment": “postgres Rul3z", "groups": [“"sysadmins", "postgres" ], "ssh_keys": "ssh-rsa …..", "id": “john", "shell": "/bin/bash" }

31. Data Bags are Searchable! pg_users = search(:users, “groups:postgres”) group “postgres” do members pg_users end

32. Code/data Split Recipes Templates Attributes Data Bags Node Object Role Cookbook run_list Node Object Role Environments The fact that attributes are in cookbooks, roles, environments, And the node itself can be confusing

33. tl;dr How do I get Started? Do the Quick start using hosted chef, free for 5 nodes http://wiki.opscode.com/display/chef/Quick+Start You can use Ubuntu, Mac OS X, and maybe Windows

34. Possible Corporate Setup PROD-Chef Server PROD QA DEV DEV-Chef Server Bar Foo Dev Playground: Devs have full access To chef-server Disposable nodes for testing cookbooks Only sysadmins Have chef access

35. Tools Chef web interface – Pretty! Ohai – collects information about node Knife – command-line tool Shef – interpreter for working with cookbooks git - not part of chef, but hard to use chef without also using git

36. A Very Simple Recipe

37. This should look familiar

38. How we can use Chef Sysadmins write cookbooks and maintain chef-server Devs can also write cookbooks to help the sysadmin Store of configuration information Sysadmins will spend more time managing configurations and less time managing individual servers

39. Questions? Bryan Berry skype: berrdawg [email_address] Portions of this presentations were taken liberally from Joshua Timberman’s Chef 101 presentation Copyright Bryan W. Berry 2011 Creative Commons 3.0 Unported CC-BY-SA