====== Shared Libraries ======

**General Information**

Jenkins shared libraries are re-usable custom steps, variables, functions, and classes.

**Checklist**
  * Jenkins server setup/configured
  * Jenkins pipeline job(s) configured

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====== Shared Library Git Project ======

Create a new git project that will contain the Jenkins shared library.

Directory structure:
  * vars/  -> Custom steps in <name>.groovy format
  * src/  -> Other common code (classes, metadata)

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Example: https://gitlab.com/whowe/jenkins-shared-library

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====== Jenkins Server: Configure Shared Library ======

Edit the Jenkins server settings to be able to use the shared library

  * Manage Jenkins
    * Configure System
    * Under "Global Pipeline Libraries", click "Add"
      * Library
        * Name: <short-descriptive-name>  (will be used in Jenkinsfiles to access shared library)
          * The example pipeline below assumes the library name is: "library-example"
        * Default version: <branch or tag to use as default> (example: master)
        * Retrieval method
          * Select "Modern SCM"
          * Select "Git" or "GitHub"
          * Project Repository: <paste in URL of your git shared library repo, same as clone URL>
          * Credentials: <select git credentials>
    * Click Save

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====== Jenkins Pipeline: Import Shared Library ======

Configure a Jenkinsfile pipeline to use the shared library and then access the custom step via its filename (minus extension).

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Example: 
  * Pipeline: https://gitlab.com/whowe/jenkins-pipelines/blob/master/Jenkinsfile.shared-library
  * Above pipeline accesses the custom step here: https://gitlab.com/whowe/jenkins-shared-library/blob/master/vars/hello.groovy

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