Book Image

Chef Cookbook - Third Edition

By : Matthias Marschall
Book Image

Chef Cookbook - Third Edition

By: Matthias 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 (15 chapters)
Chef Cookbook - Third Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Developing recipes with local mode


If running your own Chef server seems like overkill and you're not comfortable with using the hosted Chef, you can use local mode to execute cookbooks.

Getting ready

  1. Create a cookbook named my_cookbook by running the following command:

    mma@laptop:~/chef-repo $ chef generate cookbook cookbooks/my_cookbook
    Compiling Cookbooks...
    Recipe: code_generator::cookbook
    ...TRUNCATED OUTPUT...
    
  2. Edit the default recipe of my_cookbook so that it creates a temporary file:

    mma@laptop:~/chef-repo $ subl cookbooks/my_cookbook/recipes/default.rb
    file "/tmp/local_mode.txt" do
        content "created by chef client local mode"
        action :create
    end
    

How to do it…

Let's run my_cookbook on your local workstation using the Chef client's local mode:

  1. Run the Chef client locally with my_cookbook in the run list:

    mma@laptop:~/chef-repo $ chef-client --local-mode -o my_cookbook
    [2016-10-03T20:37:02+02:00] INFO: Started chef-zero at chefzero://localhost:8889 with repository at /Users/matthias.marschall/chef-repo
      One version per cookbook
    
    [2016-10-03T20:37:02+02:00] INFO: Forking chef instance to converge...
    Starting Chef Client, version 12.14.89
    [2016-10-03T20:37:02+02:00] INFO: *** Chef 12.14.89 ***
    [2016-10-03T20:37:02+02:00] INFO: Platform: x86_64-darwin13
    ...TRUNCATED OUTPUT...
    Chef Client finished, 1/1 resources updated in 04 seconds
    
  2. Validate that the Chef client run creates the desired temporary file on your local workstation:

    mma@laptop:~/chef-repo $ cat /tmp/local_mode.txt
    created by chef client local mode
    

How it works…

The --local-mode (short form: -z) parameter switches the Chef client into local mode. Local mode uses chef-zero—a simple, in-memory version of the Chef server provided by Chef DK—when converging the local workstation.

By providing the -o parameter, you override the run list of your local node so that the Chef client executes the default recipe from my_cookbook.

There's more…

Chef-zero saves all modifications made by your recipes to the local filesystem. It creates a JSON file containing all node attributes for your local workstation in the nodes directory. This way, the next time you run the Chef client in local mode, it will be aware of any changes your recipes made to the node.

Running knife in local mode

You can use knife in local mode, too. To set the run list of a node named laptop (instead of having to override it with -o), you can run the following command:

mma@laptop:~/chef-repo $ knife node run_list add -z laptop 'recipe[my_cookbook]'

Moving to hosted Chef or your own Chef server

When you're done editing and testing your cookbooks on your local workstation with chef-zero, you can seamlessly upload them to hosted Chef or your own Chef server:

Note

Make sure you bump the version number of modified cookbooks in their metadata.rb file and commit them to your version control system before uploading to the Chef Server.

mma@laptop:~/chef-repo $ berks upload
Uploaded ...

See also