This document provides an overview of using Chef and Vagrant to automate server configuration and deployment. It discusses: - Installing Chef and using tools like chef-apply, chef-solo, and knife to configure servers - Modeling infrastructure as code using resources, recipes, and cookbooks - Using community cookbooks and Berkshelf for dependency management - Provisioning nodes automatically with chef-solo and Vagrant - Developing cookbooks to deploy applications using tools like the Git resource

1. CHEF, VAGRANT
AND FRIENDS
AUTOMATING YOUR ENVIRONMENTS

2. @benmcrae
• Software engineer
• CompareTheMarket.com
• Travelling & listening to music
• Coffee / real ale drinker

3. YOU?

4. MASTER CHEFS

5. SOFTWARE!
CONFIGURATION
MANAGEMENT

7. Chef can automate how you
configure, deploy and scale
your servers and applications.

9. GETTING
STARTED

10. Installing Chef 11
!
Chef Omnibus (Linux, OS X, Windows)
Chef DK (April 2014, v0.1.0) (Bundled software)
Gem (Ruby 1.9.3 recommended)

11. Chef CLI tools
ohai (node attributes)
chef-apply (execute a single recipe from the command line)
chef-solo (execute run lists and cookbooks on a node)
chef-client (retrieves & executes run lists & cookbooks on nodes)
knife (interact with chef server)

12. INFRASTRUCTURE
AS CODE

13. Resources
Resources represent a piece of the system and its
desired state. Some resources available:!
• Directories
• Users
• Groups
• Services
• Packages

15. Resource Syntax
A resource is a Ruby block with four components:
• A type
• A name
• One (or more) attributes (with values)
• One (or more) actions

16. Recipe
Recipes are what you write to install and configure
things on your machine.!
• Authored using a Ruby DSL
• Made from multiple resources
• Can include other recipes
• Single responsibility in purpose
• Belongs to a Cookbook

17. Recipe DSL
A Ruby DSL, with specific methods to write
chef recipes and resource blocks.
Common Ruby syntax can be used with the
Recipe DSL methods. if / case statements…

18. FIRST RECIPE

19. Ingredients
• Using chef-apply and a single recipe
• Create a new developer user on the system
• Install Git using the OS package manager
• Create a .gitconfig file for the developer user

20. stage-1
https://github.com/benmcrae/ddd-chef-examples/tree/master/stage-1

21. Chef Run
• Recipe loaded
• Resources are arranged in an ordered queue
• Each resource is mapped to a Provider!
• The node Converges by executing each provider

22. Providers
Providers define steps that are needed to
bring a piece of the system from its current
state into the desired state.

23. Idempotent
A recipe can run multiple times on the
same system and the results will always be
identical.

24. RETROSPECTIVE

25. Outcomes
• Poor single responsibility
• Use better suited resources e.g. template / file
• Fixed values could be swapped for attributes

26. Next Steps
1. Create cookbook from existing recipe
2. Refactor outcomes from retrospective

27. FIRST COOKBOOK

28. Cookbook
A cookbook defines a scenario, such as
everything needed to install and configure
Apache and the resources that support it.

30. Cookbook Folders
• attributes - attribute files, loaded in alphabetical order!
• files - stored files for file and directory resources!
• libraries - arbitrary ruby libraries, used in recipes!
• providers - custom providers (LWRP)!
• recipes - recipe files!
• resources - custom resources (LWRP)!
• templates - erb files for the template resource

31. Cookbook Generators
• knife cookbook create ‘cookbook name’
• berks cookbook ‘cookbook name’

32. Metadata File
• The metadata.rb sits in the cookbook root directory
• Defines cookbook name, version, and description
• Can declare dependencies on other cookbooks
• List supported operating systems

34. REFACTOR

35. Template Resource
• Uses ERB (Embedded Ruby) files
• Supports variables and hashes in templates
• Multi nested folders designed to support
distributing files across platforms
• Best practice: set variables using attributes

37. Node Object
• Attributes - An attribute is a specific piece of data
about the node!
• Run list - A run-list is an ordered list of recipes
and/or roles that are run in an exact order

38. Attributes
!
• Attributes can be defined by the node, recipes,
cookbooks, roles and environments!
• Node information. i.e. IP / MAC addresses, OS info
• Recipe information. i.e. directory paths, users,
application data

40. Overriding Attributes

41. Ohai
Ohai is a CLI tool that is used to detect attributes on a node!
• Platform details
• Network usage
• Memory usage
• Processor usage

42. Run List
• A run-list defines all of the configuration settings
that are necessary for a node to converge
• An ordered list of roles and/or recipes that are run
in an exact order

43. chef-solo
• chef-solo allows using cookbooks on nodes without
using Chef server
• Cookbooks & dependencies must be on the node
• Limited in functionality compared to chef-server
• Requires configuration; run-list and attributes

44. stage-2
https://github.com/benmcrae/ddd-chef-examples/tree/master/stage-2

45. Chef Run
• Builds node object!
• Expands run-list
• Compiles Resources in an ordered queue
• Each resource is mapped to a Provider!
• The node Converges by executing each provider

46. RETROSPECTIVE

47. Outcomes
• A single cookbook to manage our developer user
• A cookbook that can be used with both chef-solo
and chef-client (Chef Server)

48. Next Steps
• Introduce community cookbooks and Berkshelf
• Install Ruby 2.1.2, using Berkshelf

49. COMMUNITY
COOKBOOKS

50. Community Cookbooks
• An online Open Source cookbook repository,
maintained and used by the chef community.
• Trusted cookbooks can be downloaded from -
http://community.opscode.com
• Cookbook dependencies are not automatically
downloaded. This must be done by looking through
the cookbook metadata file, and manually
downloading listed cookbooks.

51. Berkshelf
• The cookbook dependency manager
• gem install berkshelf
• Used to maintain cookbooks on your Chef Server
• Written by Jamie Windsor, and Seth Vargo

52. Berksfile
• Lives in the root directory of the Cookbook
• Lists each cookbook name, and version (optional)
which your cookbook depends on
• Ability to read cookbook dependencies from
metadata.rb file
• Traverses over other cookbook dependencies

54. stage-3
https://github.com/benmcrae/ddd-chef-examples/tree/master/stage-3

55. RETROSPECTIVE

56. Outcomes
• Implemented a community cookbook with the aid of
Berkshelf.
• Applied our knowledge of attributes to other
cookbooks.

57. Next Steps
• Provision the node automatically with chef-solo and
Vagrant.
• Create a new recipe to git clone our ruby app into
the developer home directory.

59. • Create and configure lightweight, reproducible,
and portable development environments.
• Vagrant stands on the shoulders of giants.
Machines are provisioned on top of VirtualBox,
VMware, AWS, or any other provider.
• Provision machines with, shell scripts, Chef, or
Puppet.

60. Commands
• vagrant init hashicorp/precise32
• vagrant up
• vagrant provision
• vagrant halt
• vagrant destroy

62. Vagrant Provision
• Move the run list and attributes into the Vagrantfile
• Vagrant will run chef-solo on VM start, or by running
the provision command

63. Git Resource
• Manage source control resources that exist in a git
repository
• Functionality for revision and branching control
• Offers both export and syncing abilities

64. stage-4
https://github.com/benmcrae/ddd-chef-examples/tree/master/stage-4

65. RETROSPECTIVE

66. Outcomes
• Used Vagrant to run chef-solo and setup our node
• Established our cookbook development workflow
• Finished cookbook

67. VAGRANT CONT.

68. More Features
• Full support for both Linux and Windows guest’s
• Mount directories using either NFS, SMB or Rsync
• Multi machine environments
• Network support - port forwarding, private networks

69. Vagrant Cloud
• Share a link to your web server to a teammate
across the country
• Community collection of fully baked box images
• Distribute versionable private environments to your
team

70. Share / Connect
• Share SSH access to other vagrant users
• Share the whole machine as a local entity to other
vagrant users

71. Vagrant Plugins
• vagrant plugin install <plugin_name>
• vagrant-sahara (operate in a sandbox environment)
• vagrant-proxy (define http and https proxies)

72. Chef Reading
• Test-Driven Infrastructure with Chef, 2nd Edition
- Steven Nelson-Smith
• Chef Infrastructure Automation Cookbook
- Matthias Marschall
• Learning Chef (Released Sep 2014)
- Seth Vargo, Mischa Taylor
• https://learnchef.opscode.com/

73. Vagrant Reading
• Vagrant: Up and Running - Mitchell Hashimoto
• http://docs.vagrantup.com/
• http://www.vagrantup.com/blog.html

74. THANK YOU