jenkins/custom-war-packager repository overview

⁠Jenkins Custom WAR Packager

Custom WAR Packager (CWP) allows building ready-to-fly Jenkins packages using a YAML specification. The tool can produce Docker images, WAR files, and Jenkinsfile Runner⁠ docker images (aka single-shot Jenkins masters). These bundles may include Jenkins core, plugins, extra libraries, and self-configuration via Groovy Hook Scripts⁠ or Configuration-as-Code Plugin⁠ YAML files.

See this blog post⁠ for more information.

⁠Demo

• Jenkins WAR - all latest⁠ - bundles master branches for core and some key libraries/modules
• Jenkins WAR - all latest with Maven⁠ - same as a above, but with Maven
• External Task Logging to Elasticsearch⁠ - runs External Logging demo and preconfigures it using System Groovy Hooks. The demo is packaged with Docker, and it provides a ready-to-fly Docker Compose package.
• Configuration as Code⁠ - configuring WAR with Configuration-as-Code Plugin⁠ via YAML
• Core components build⁠ - demonstrates how to modify core components (libraries, modules)
• Custom WAR Packager CI Demo⁠ - Standalone demo with an integrated CI flow
• Jenkinsfile Runner⁠ - Packaging of Docker image for Jenkinsfile Runner

⁠Usage

The tool offers a CLI interface and a Maven Plugin wrapper.

⁠CLI

java -jar custom-war-packager-cli.jar -configPath=mywar.yml -version=1.0-SNAPSHOT -tmpDir=tmp

After the build the generated WAR file will be put to tmp/output/target/${artifactId}.war.

To run the tool in a demo mode with this config⁠, use the following command:

java -jar war-packager-cli.jar -demo

Invoke the tool without options to get a full CLI options list.

⁠Maven

Maven plugin runs the packager and generates the artifact. The artifact will be put to "target/custom-war-packager-maven-plugin/output/target/${bundle.artifactId}.war" and added to the project artifacts.

  <build>
    <plugins>
      <plugin>
        <groupId>io.jenkins.tools.custom-war-packager</groupId>
        <artifactId>custom-war-packager-maven-plugin</artifactId>
        <version>@project.version@</version>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>custom-war</goal>
            </goals>
            <configuration>
              <configFilePath>spotcheck.yml</configFilePath>
              <warVersion>1.1-SNAPSHOT</warVersion>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

Note that this plugin invokes Maven-in-Maven, and that it won't pass build options to the plugin. Configuration file can be used to configure the downstream builder.

⁠Prerequisites

• Maven 3.5.0 or above
• Java 8
• Git (if any Git sources are defined)

Custom WAR Packager offers a Docker Image⁠ which bundles all the required tools.

⁠Configuration file

Example:

bundle:
  groupId: "io.github.oleg-nenashev"
  artifactId: "mywar"
  description: "Just a WAR auto-generation-sample"
  vendor: "Jenkins project"
buildSettings:
  docker:
    base: "jenkins/jenkins:2.121.1"
    tag: "jenkins/demo-external-task-logging-elk"
    build: true
war:
  groupId: "org.jenkins-ci.main"
  artifactId: "jenkins-war"
  source:
    version: 2.107
plugins:
  - groupId: "org.jenkins-ci.plugins"
    artifactId: "matrix-project"
    source:
      version: 1.9
  - groupId: "org.jenkins-ci.plugins"
    artifactId: "durable-task"
    source:
      git: https://github.com/jglick/durable-task-plugin.git
      branch: watch-JENKINS-38381
  - groupId: "org.jenkins-ci.plugins.workflow"
    artifactId: "workflow-durable-task-step"
    source:
      git: https://github.com/jglick/workflow-durable-task-step-plugin.git
      commit: 6c424e059bba90fc94a9c1e87dc9c4a324bfef26
  - groupId: "io.jenkins"
    artifactId: "configuration-as-code"
    source:
      version: 0.11-alpha-rc373.933033f6b51e
libPatches:
  - groupId: "org.jenkins-ci.main"
    artifactId: "remoting"
    source:
      git: https://github.com/jenkinsci/remoting.git
systemProperties: {
     jenkins.model.Jenkins.slaveAgentPort: "50000",
     jenkins.model.Jenkins.slaveAgentPortEnforce: "true"}
groovyHooks:
  - type: "init"
    id: "initScripts"
    source: 
      dir: scripts
casc:
  - id: "jcasc-config"
    source:
      dir: jenkins.yml

There are more options available. See the linked demos for examples.

⁠BOM support

The plugin supports Bill of Materials (BOM), described in JEP-309⁠, as an input.

If BOM is defined, Custom WAR Packager will load plugin and component dependencies from there. The example below takes the input from BOM and produces custom WAR and Docker packages.

bundle:
  groupId: "io.jenkins.tools.war-packager.demo"
  artifactId: "bom-demo"
buildSettings:
  bom: bom.yml
  environment: aws
  docker:
    base: "jenkins/jenkins:2.121.2"
    tag: "jenkins/cwp-bom-demo"
    build: true

An example of such configuration is available here⁠.

⁠Plugins from POM

In order to simplify packaging for development versions, it is possible to link Custom War Packager to the POM file so that it takes plugins to be bundled from there.

If the pom option is set, all dependencies will be added, including test ones. The current parent will be also bundled unless the pomIgnoreRoot flag is set.

bundle:
  groupId: "io.jenkins.tools.war-packager.demo"
  artifactId: "pom-input-demo"
buildSettings:
  pom: pom.xml
  pomIgnoreRoot: true
war:
  groupId: "org.jenkins-ci.main"
  artifactId: "jenkins-war"
  source:
    version: 2.121.1

Example is available here⁠.

⁠Advanced features

Features:

• Rebuilding Jenkins core with custom dependencies (e.g., Remoting or Stapler)
• Adding extra libraries to the Jenkins core so that they can be used in extensions

⁠Limitations

Currently, the tool is in the alpha state. It has some serious limitations:

• All built artifacts with Git source are being installed to the local repository
  • Versions are unique for every commit, so beware of local repo pollution
• System properties work only for a custom jenkins.util.SystemProperties class defined in the core
  • Use Groovy Hook Scripts if you need to set up other system properties
• libPatches steps bundles only a specified JAR file, but not its dependencies Dependencies need to be explicitly packaged as well if they change compared to the base WAR file
  • libExcludes can be used to remove dependencies which are not required anymore