Pipeline: Shared Groovy Libraries through Nexus retrieval

The official pipeline-groovy-lib-plugin does provide a way to retrieve shared libraries through a SCM, such as Git. The goal of this Nexus plugin is to add the ability to retrieve shared libraries from Nexus (via the @Library declaration in a Jenkinsfile).

Installation of the plugin

Installation using a pre-built artifact

Installing from the plugins site (recommended)

The plugin is referenced as an official plugin on the Jenkins update site, so you should be able to use the integrated search in the Plugin section.

Install the plugin using the pre-built .hpi file

You can find the archives of all the versions of the Plugin on the Jenkins update site. You can also download the wished plugin release from the GitHub releases section. Then, go to the Jenkins Administration Plugins UI > Advanced section and upload the plugin .hpi file.

Installation from source

You can follow the steps hereafter to install the plugin:

• Clone this repository
• Run mvn clean package in order to compile the sources and package them in a .hpi file
• Follow the instructions that can be found on the Jenkins website and install the plugin that has been packaged in target/pipeline-global-lib-nexus.hpi

How to use the plugin

Pre-requisite: a packaged shared library

In order to be able to use this plugin, you need to package your library (probably during a Continuous Integration build) and publish it to Nexus so Maven can download the artifact again. You should end up with a ZIP file with the following structure:

> unzip -vl pipeline-libraries.zip
Archive:  pipeline-libraries.zip
 Length   Method    Size  Cmpr    Date    Time   CRC-32   Name
--------  ------  ------- ---- ---------- ----- --------  ----
     xxx  Defl:N      xxx  37% 03-21-2019 12:14 7d354e1f  resources/a-rsc-needed
    xxxx  Defl:N     xxxx  68% 03-21-2019 12:14 fefba77f  src/your/package/YourGroovyClass.groovy
     xxx  Defl:N      xxx  33% 03-21-2019 12:14 5b6808ab  vars/yourvar.groovy
     xxx  Defl:N      xxx  39% 03-21-2019 12:14 5842cc52  vars/yourvar.txt
--------          -------  ---                            -------
  xxxxxx           xxxxxx  x%                            n files

If you want to package it like this with maven, you can use the following. In your pom.xml

<build>
   <plugins>
      <plugin>
            <artifactId>maven-assembly-plugin</artifactId>
            <version>2.6</version>
            <executions>
               <execution>
                  <configuration>
                        <finalName>your-library</finalName>
                        <descriptors>
                           <descriptor>assembly.xml</descriptor>
                        </descriptors>
                  </configuration>
                  <id>make-assembly1</id>
                  <phase>package</phase>
                  <goals>
                        <goal>single</goal>
                  </goals>
               </execution>
            </executions>
      </plugin>
   </plugins>
</build>

The assembly.xml file:

<assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.3"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.3 http://maven.apache.org/xsd/assembly-1.1.3.xsd">
  <id>lib</id>

  <formats>
    <format>zip</format>
  </formats>

  <includeBaseDirectory>false</includeBaseDirectory>

  <fileSets>
    <fileSet>
      <directory>.</directory>
      <outputDirectory>/</outputDirectory>
      <lineEnding>unix</lineEnding>
      <includes>
        <include>src/**</include>
        <include>vars/**</include>
        <include>resources/templates/*.json</include>
        <include>resources/*.sh</include>
        <include>version.txt</include>
      </includes>
    </fileSet>
  </fileSets>

</assembly>

A basic example project is available here, which contains a scripted pipeline executing a couple of basic steps.

Constraints

The plugin only supports ZIP shared libraries for the moment.

Setup of the plugin

The plugin is configurable on the Jenkins UI, at different levels:

• On Global System Configuration page (Administration)
• On Folder Configuration page
• On Pipeline Configuration page

Jenkins administrators can set global libraries on the Administration page, while Jenkins users can set libraries either on the Folder view or on the Pipeline view.

The generic documentation to reference a new shared library can be found here.

In the Jenkins UI

In Administration / Folder / Pipeline configuration views:

• Go to the Global Pipeline Libraries section and add a new library. You should see 3 different retrieval methods: Modern SCM, Nexus and Legacy SCM.
• Give it a name and a default version
• Decide if you want to load it implicitly or not
• Provide the artifact details used to retrieve the shared libraries in the following format: <groupId>:<artifactId>:<version>:<packaging>:<optional classifier>. In the example the following shared library is used: com.roylenferink:jenkins-shared-library:${library.jenkins-lib.version}:zip:lib.
• Provide a location to an available Maven installation. If MAVEN_HOME is not specified, the first-found Maven installation will be used. If Maven cannot be found the job will fail. In the example the following Maven location is used /tools/apache-maven-3.6.2.

The artifact details are version-dynamic, it follows the Jenkins standard annotation ${library.<library_name>.version} that is afterwards replaced either by the default version provided by the admin, or the version specified by the user Jenkinsfile in the @Library annotation.

Directly in the Jenkinsfile

Users can also retrieve shared libraries from their Jenkinsfile, by defining it with this syntax:

library identifier: 'external-shared-libraries@4.1.0', retriever: nexus(
   artifactDetails: 'com.roylenferink:jenkins-shared-library:${library.external-shared-libraries.version}:zip:lib',
   mavenHome: '/tools/apache-maven-3.6.2')

Contributing to this plugin

Contributions to this plugin are definitely welcome! Follow the steps in the DEVELOPMENT.md to get started.

License

This project is licensed under the terms of the MIT License.