Understanding Artifacts in Jenkins: A Practical Guide (with examples)

Introduction

Jenkins, an open-source automation server, has significantly simplified continuous integration and continuous deployment for software projects. One feature that plays a pivotal role in these processes is the concept of artifacts. In Jenkins, artifacts are files which are generated during the build process and are archived by Jenkins for later use. This tutorial will dive into the nitty-gritty of artifacts in Jenkins, providing practical examples each step of the way.

What are Artifacts?

Before exploring the technical depths, it’s crucial to have a clear understanding of what artifacts are. In the context of Jenkins and software development, artifacts are the result of a build process. This can include compiled code, configuration files, databases, documentation, or any other artifact type related to your project. Artifacts are important because they allow you to save the output of a build process so it can be used in subsequent steps or stored for long-term use.

Creating and Archiving Artifacts in Jenkins

Let’s start with the basics of creating and archiving artifacts. The simplest step to achieve this is to configure your build job in Jenkins to archive the generated artifacts. Here’s a step-by-step guide:

1. Log in to your Jenkins server.
2. Navigate to your project’s configuration page.
3. Find the ‘Post-build Actions’ section.
4. Select ‘Archive the artifacts’.
5. In the ‘Files to archive’ field, specify the path to your build artifacts.
6. Save your configuration.

For example, if your project generates a .jar file in a directory named target, the field should be configured as target/*.jar.

Using Artifacts in Subsequent Builds

After archiving artifacts, a common necessity is to use them in subsequent builds or deployments. Jenkins provides a mechanism for this as well. One practical way is to use the Copy Artifact plugin, which can be configured as follows:

1. Install the Copy Artifact plugin through Jenkins’ Manage Plugins page.
2. Configure a job that will use the artifact by adding a ‘Copy artifact from another project’ step in the ‘Build’ section.
3. Specify the project to copy from, the build to copy (you can use variables like
LAST_SUCCESSFUL_BUILD), and the target directory.

Advanced Artifact Handling

As developers become more accustomed to Jenkins and its functionalities, the need for advanced artifact handling often arises. Let’s talk about setting up an artifact repository server and integrating it with Jenkins.

A popular choice for a repository server is Nexus or Artifactory. These servers allow you to store, retrieve, and manage your artifacts efficiently. To integrate Jenkins with one of these servers, follow these steps:

1. Set up your preferred artifact repository server (e.g., Nexus, Artifactory).
2. In Jenkins, install the plugin that corresponds to your repository server (e.g., Nexus Artifact Uploader, Artifactory).
3. In your Jenkins project, configure the plugin to upload generated artifacts to your repository server upon successful build completion.

This can be particularly useful for complex projects where artifacts need to be shared across distinct projects or even development teams.

Example Scenarios

To better understand the concepts discussed, let’s walk through some example scenarios where Jenkins artifacts are used:

Scenario 1: Archiving a Java Project’s JAR

This example involves a simple Java project where a .jar file is generated. The goal is to archive this artifact for later use:

Post-build Actions: Archive the artifacts
Files to archive: target/*.jar

Once the build completes successfully, the specified .jar file will be archived and accessible from the Jenkins build dashboard.

Scenario 2: Sharing Artifacts Between Projects

In this scenario, we assume there are two projects: Project A generates an artifact that Project B needs to use. Here’s how you set up Project B to retrieve Project A’s artifact:

Build: Copy artifact from another project
Project name: Project A
Which build: Last successful build
Directory: ./artifacts

With this setup, Project B can always use the latest successful artifact generated by Project A.

Conclusion

Understanding artifacts in Jenkins enhances the automation capabilities of your CI/CD pipeline. It not only allows for the archiving of build results for later use but also facilitates sharing across jobs and projects. By mastering artifacts in Jenkins, you can ensure a more seamless and efficient development process.