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

• You can find the source code of chef-zero at https://github.com/chef/chef-zero
• Read more about the Chef client's local mode and how it relates to Chef solo at https://blog.chef.io/2013/10/31/chef-client-z-from-zero-to-chef-in-8-5-seconds/