Overview of CookStyle

CookStyle vs Rubocop⚡

Specifically designed for the Chef Cookbook code, CookStyle is more reliable than Rubocop. Linting Cookbooks with CookStyle will make them more consistent and less likely to fail CI tests.

Tailored cops

Because cookbook creation differs from regular Ruby program development, we have a customized collection of Rubocop officers on hand. Cops that are not beneficial for cookbook creation are disabled, and rules are occasionally altered to enforce a different behavior. We've also added a collection of Chef Infra-specific officers to the standard RuboCop package. These cops can only be found in CookStyle and will assist you in creating more dependable and future-proof cookbooks.

New cops

Rubocop is constantly being updated with new cops. New cops can cause CI tests to fail in an existing codebase, forcing writers to continuously change their code.

We update the RuboCop engine in CookStyle for bug and performance updates, but we only alter the set of officers that fail tests once a year, in April, during Chef Infra's main release. All new officers are introduced at the RuboCop "refactor" alert level, which means they will alert to the screen while you run CookStyle but will not fail a build. You can upgrade CookStyle releases without having to update your infrastructure code because of its dependability.

Run CookStyle🏃

CookStyle is normally executed from the command line, against a single cookbook and the Ruby files contained within it:

cookstyle /path/to/cookbook

CookStyle can also be launched from the root of a specific cookbook directory:

cookstyle .

CookStyle returns a list of the assessment results via standard output.

Output

Cooking output:

• The number of files discovered and analyzed. As an example: 8 files are being examined.
• As a series of symbols, it lists the results of those files. As an example: CWCWCCCC
• For each symbol, specify the file name, line number, character number, type of issue or error, description of the issue or error, and location in the source code where the issue or error can be found.

The syntax for a CookStyle evaluation is as follows:

FILENAME:LINE_NUMBER:CHARACTER_NUMBER: TYPE_OF_ERROR: MESSAGE
SOURCE CODE

For example:

cookbooks/apache/attributes/default.rb:1:9: C: When you don't need string interpolation or special symbols, use single-quoted strings.
default["apache"]["index file"] = "index.html"
        ^^^^^^^^

Symbols

To express the outcome of an evaluation, the following symbols occur in the standard output:

Symbol	Description
.	There are no problems with the file.
C	The file has a convention problem.
E	There is an error in the file.
F	There is a fatal error in the file.
W	There is a warning in the file.
R	The code in the file should be refactored.

Autocorrecting CookStyle Warnings⚠️

Many of CookStyle Cops support autocorrecting offenses. Run the following commands from the cookbook directory to autocorrect code:

cookstyle -a .

After running this script, take special attention to confirming that the autocorrection logic produced suitable cookbook code.

.rubocop.yml

Override the default CookStyle settings for enabled and disabled rules with the a.rubocop.yml file in a cookbook. Only enabled rules—either those in CookStyle's enabled.yml file or those specifically enabled in a cookbook's.rubocop.yml file—will be used throughout the evaluation. Any useless rules should be disabled in the.rubocop.yml file.

Because each cookbook has its own.rubocop.yml file, each cookbook can have its own set of enabled, disabled, and custom rules. However, all cookbooks are more likely to contain the same collection of enabled, disabled, and custom rules. When RuboCop is run against a cookbook, it loads the entire set of enabled and disabled rules (as described in CookStyle's enabled.yml and disabled.yml files) and compares them to the cookbook's.rubocop.yml settings.

The.rubocop.yml file should be used to specify custom rules. The enabled or disabled state of rules in the a.rubocop.yml file takes precedence over the enabled.yml and disabled.yml files.

Syntax

The syntax of the a.rubocop.yml file is as follows:

NAME_OF_RULE:
	Description: 'a description of a rule'
	Enabled : (true or false)
	KEY: VALUE

 

where,

• The rule name is "NAME_OF_RULE."
• "Description" is the string that appears in standard output and describes the rule if it is activated during the evaluation.
• "Enabled" enables (true) or disables (false) a rule; for non-custom rules, this value will override the settings in the CookStyle "enabled.yml" and "disabled.yml" files.
• If necessary, "KEY: VALUE" adds more information to a rule. For example, "Max: 50" limits the "LineLength" rule to 50 characters.

.rubocop_todo.yml🎗️

In order to record the current status of each evaluation, use the a.rubocop_todo.yml file and then write them to a file. This allows for the review of evaluations one at a time. Disable any unhelpful evaluations before addressing the ones that are.

Run the following command to generate the.rubocop_todo.yml file:

cookstyle --auto-gen-config

Frequently Asked Questions ⁉️

What does a DevOps Chef do?

Chef is an open-source cloud deployment and configuration management tool. Anyone can use it to organize servers, whether they are in a departmental data center or the cloud.

Why is Chef crucial to DevOps?

Chef treats infrastructure like code, which aids in finding a solution. The machine setup is explained in a Chef's recipe rather than having to be changed manually.

In DevOps, what do Chef and Puppet do?

The DevOps pioneers Chef and Puppet both provide well-liked enterprise-grade configuration automation tools.

What is a command line interface?

A command-line interface(CLI) is a text-based user interface (UI) used to get commands from the user in the form of texts.

In which language is Chef written?

Chef is written in ruby and erlang programming language.

Conclusion

This article discussed the Overview of CookStyle including CookStyle vs Rubocop, Autocorrecting CookStyle Warnings, .rubocop.yml.

We hope this blog on Overview of CookStyle was helpful.

You can refer to other similar articles as well -  

• Overview of Chef Spec
• Overview of Chef Inspec
• Overview of Chef Workstation
   

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