Jenkins Configuration as Code (JCasC)

The JCasC plugin can be installed through the Jenkins Plugin Manager by navigating to the Available plugins tab and searching for 'Configuration as Code.' After installation, you define your Jenkins settings in YAML files and point Jenkins to them using the plugin's configuration interface or the CASC_JENKINS_CONFIG environment variable.

JCasC uses YAML files to define Jenkins settings including security realms, authorization strategies, agents, build tools, cloud configurations, and job definitions. These YAML files can be stored in version control systems like Git alongside other infrastructure code.

JCasC can define certain job configurations within its YAML structure, but many teams pair it with tools like Job DSL or Jenkins Pipeline-as-Code for more complex job definitions. JCasC is most commonly used for global Jenkins configuration rather than individual pipeline definitions.

By storing the entire Jenkins configuration in version-controlled YAML files, JCasC allows administrators to spin up a fresh Jenkins instance and apply the saved configuration to reproduce the exact same setup. This eliminates manual reconfiguration and ensures consistency across development, staging, and production Jenkins environments.