Browse Library
Sign In Start Free Trial
Close icon Search icon
Account
Browse Library Advanced Search Sign In Start Free Trial

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Chef Cookbook
  • Toc
  • feedback
Chef Cookbook

Chef Cookbook

By : Marschall
close
Chef Cookbook

Chef Cookbook

By: Marschall

Overview of this book

Chef is a configuration management tool that lets you automate your more cumbersome IT infrastructure processes and control a large network of computers (and virtual machines) from one master server. This book will help you solve everyday problems with your IT infrastructure with Chef. It will start with recipes that show you how to effectively manage your infrastructure and solve problems with users, applications, and automation. You will then come across a new testing framework, InSpec, to test any node in your infrastructure. Further on, you will learn to customize plugins and write cross-platform cookbooks depending on the platform. You will also install packages from a third-party repository and learn how to manage users and applications. Toward the end, you will build high-availability services and explore what Habitat is and how you can implement it.
Table of Contents (9 chapters)
close
close
Preface
Preface
What this book covers
What you need for this book
Who this book is for
Sections
Conventions
Reader feedback
Customer support
Free Chapter
1
1. Chef Infrastructure
chevron up
1. Chef Infrastructure
Introduction
Using version control
Installing the Chef Development Kit on your workstation
Using the hosted Chef platform
Managing virtual machines with Vagrant
Creating and using cookbooks
Inspecting files on your Chef server with knife
How to do it…
How it works…
There's more…
See also
Defining cookbook dependencies
Managing cookbook dependencies with Berkshelf
Using custom knife plugins
Deleting a node from the Chef server
Developing recipes with local mode
Using roles
Using environments
Freezing cookbooks
Running the Chef client as a daemon
2
2. Evaluating and Troubleshooting Cookbooks and Chef Runs
2. Evaluating and Troubleshooting Cookbooks and Chef Runs
Introduction
Testing your Chef cookbooks with cookstyle and Rubocop
Flagging problems in your Chef cookbooks with Foodcritic
Test-driven development for cookbooks using ChefSpec
Compliance testing with InSpec
Integration-testing your Chef cookbooks with Test Kitchen
Showing affected nodes before uploading cookbooks
Overriding a node's run list to execute a single recipe
Using chef-shell
Using why-run mode to find out what a recipe might do
Debugging Chef client runs
Inspecting the results of your last Chef run
Using Reporting to keep track of all your Chef client runs
Raising and logging exceptions in recipes
Diff-ing cookbooks with knife
Using community exception and report handlers
3
3. Chef Language and Style
3. Chef Language and Style
Introduction
Using community Chef style
Using attributes to dynamically configure recipes
Using templates
Mixing plain Ruby with Chef DSL
Installing Ruby gems and using them in recipes
Using libraries
Creating your own custom resource
Extending community cookbooks by using application wrapper cookbooks
Creating custom Ohai plugins
Creating custom knife plugins
4
4. Writing Better Cookbooks
4. Writing Better Cookbooks
Introduction
Setting environment variables
Passing arguments to shell commands
Overriding attributes
Using search to find nodes
Using data bags
Using search to find data bag items
Using encrypted data bag items
Accessing data bag values from external scripts
Getting information about the environment
Writing cross-platform cookbooks
Making recipes idempotent by using conditional execution
5
5. Working with Files and Packages
5. Working with Files and Packages
Introduction
Creating configuration files using templates
Using pure Ruby in templates for conditionals and iterations
Installing packages from a third-party repository
Installing software from source
Running a command when a file is updated
Distributing directory trees
Cleaning up old files
Distributing different files based on the target platform
6
6. Users and Applications
6. Users and Applications
Introduction
Creating users from data bags
Securing the Secure Shell daemon
Enabling passwordless sudo
Managing NTP
Installing nginx from source
Creating nginx virtual hosts
Creating MySQL databases and users
Managing Ruby on Rails applications
Managing Varnish
Managing your local workstation with Chef Pantry
7
7. Servers and Cloud Infrastructure
7. Servers and Cloud Infrastructure
Introduction
Creating cookbooks from a running system with Blueprint
Running the same command on many machines at once
Setting up SNMP for external monitoring services
Deploying a Nagios monitoring server
Using HAProxy to load-balance multiple web servers
Using custom bootstrap scripts
Managing firewalls with iptables
Managing fail2ban to ban malicious IP addresses
Managing Amazon EC2 instances
Managing applications with Habitat
8
Index
Index

Using environments

Having separate environments for development, testing, and production is a good way to be able to develop and test cookbook updates, and other configuration changes in isolation. Chef enables you to group your nodes into separate environments so as to support an ordered development flow.

Getting ready

For the following examples, let's assume that you have a node named server in the _default environment and that you have at least one cookbook (I'll use the ntp cookbook) registered with your Chef server.

How to do it…

Let's see how to manipulate environments using knife:

Note

This is only a good idea if you want to play around. For serious work, please create files describing your environments and put them under version control as described in the There's more… section of this recipe.

  1. Create your environment on-the-fly using knife. The following command will open your shell's default editor so that you can modify the environment definition:

    Note

    Make sure you've set your EDITOR environment variable to your preferred one.

    mma@laptop:~/chef-repo $ knife environment create dev
{
  "name": "dev",
  "description": "",
  "cookbook_versions": {
  },
  "json_class": "Chef::Environment",
  "chef_type": "environment",
  "default_attributes": {
  },
  "override_attributes": {
  }
}
Created dev
  2. List the available environments:
    mma@laptop:~/chef-repo $ knife environment list
_default
dev
  3. List the nodes for all the environments:
    mma@laptop:~/chef-repo $ knife node list
server
  4. Verify that the node server is not in the dev environment yet by listing nodes in the dev environment only:
    mma@laptop:~/chef-repo $ knife node list -E dev
mma@laptop:~/chef-repo $
  5. Change the environment of the server to dev using knife:
    mma@laptop:~/chef-repo $ knife node environment set server book
server:
  chef_environment: dev
  6. List the nodes in the dev environment again:
    mma@laptop:~/chef-repo $ knife node list -E dev
server
  7. Use specific cookbook versions and override certain attributes for the environment:
    mma@laptop:~/chef-repo $ knife environment edit dev
{
  "name": "dev",
  "description": "",
  "cookbook_versions": {
    "ntp": "1.6.8"
  },
  "json_class": "Chef::Environment",
  "chef_type": "environment",
  "default_attributes": {
  },
  "override_attributes": {
    "ntp": {
      "servers": ["0.europe.pool.ntp.org", "1.europe.pool.ntp.org", "2.europe.pool.ntp.org", "3.europe.pool.ntp.org"]
    }
  }
}
Saved dev

How it works…

A common use of environments is to promote cookbook updates from development to staging and then into production. Additionally, they enable you to use different cookbook versions on separate sets of nodes and environment-specific attributes. You might have nodes with less memory in your staging environment as in your production environment. By using environment-specific default attributes, you can, for example, configure your MySQL service to consume less memory on staging than on production.

Note

The Chef server always has an environment called _default, which cannot be edited or deleted. All the nodes go in there if you don't specify any other environment.

Be aware that roles are not environment-specific. You may use environment-specific run lists, though.

The node's environment can be queried using the node.chef_environment method inside your cookbooks.

There's more…

If you want your environments to be under version control (and you should), a better way to create a new environment is to create a new Ruby file in the environments directory inside your Chef repository:

mma@laptop:~/chef-repo $ cd environments
mma@laptop:~/chef-repo $ subl dev.rb
name "dev"

You should add, commit, and push your new environment file to GitHub:

mma@laptop:~/chef-repo $ git add environments/dev.rb
mma@laptop:~/chef-repo $ git commit -a -m "the dev environment"
mma@laptop:~/chef-repo $ git push

Now, you can create the environment on the Chef server from the newly created file using knife:

mma@laptop:~/chef-repo $ knife environment from file dev.rb
Created environment dev

Tip

You have to deal with two artifact storages here. You have to use your version control system and knife / Berkshelf to sync your local changes to your Chef server. The Chef server is not aware of any changes that you do when using your version control system, and vice versa.

There is a way to migrate all the nodes from one environment to another by using knife exec:

mma@laptop:~/chef-repo $ knife exec -E 'nodes.transform("chef_environment:_default") { |n| n.chef_environment("dev")

You can limit your search for nodes in a specific environment:

mma@laptop:~/chef-repo $ knife search node "chef_environment:dev"
1 item found

See also

  • If you want to set up a virtual machine as a node, see the Managing virtual machines with Vagrant recipe in this chapter
  • Read more about environments at https://docs.chef.io/environments.html
End of Section 19
Next Section
bookmark search playlist font-size

Change the font size

margin-width

Change margin width

day-mode

Change background colour

Close icon Search
Country selected
Close icon Your notes and bookmarks

Delete Bookmark

Modal Close icon
Are you sure you want to delete it?
Cancel
Yes, Delete