ci.jenkins.io-runner

This project offers environment for running Jenkinsfile instances from ci.jenkins.io locally. It is powered by Jenkinsfile Runner and Custom WAR Packager. If you want a classic runtime Jenkins master with agents, checkout my Jenkins Configuration-as-code demo.

The runner can execute buildPlugin() builds and some other commands from the Jenkins Pipeline Library. In particular, it is possible to run builds against multiple JDK and Jenkins core version combinations.

See the Limitations section below for some of known limitations.

Quickstart

1. Checkout this repo
2. Run make docker to build the base image
3. Run make clean build to build the Jenkinsfile Runner image
4. Run make run to run a simple demo
5. Run make demo-plugin to run a demo of the plugin build

Usage

The runner can be invoked against a workspace which contains a Jenkinsfile and, if needed, the project's sourcecode.

	docker run --rm -v maven-repo:/root/.m2 \
	    -v $(pwd)/demo/locale-plugin/:/workspace/ \
	    onenashev/ci.jenkins.io-runner

Developing Jenkins Pipeline Library

Jenkins Pipeline library may be passed from a volume so that it is possible to test a local snapshot.

	docker run --rm -v maven-repo:/root/.m2 \
	    -v ${MY_PIPELINE_LIBRARY_DIR}:/var/jenkins_home/pipeline-library \
	    -v $(pwd)/demo/locale-plugin/:/workspace/ \
	    onenashev/ci.jenkins.io-runner

Developer notes

Upgrade management

Current versions of Custom WAR Packager are not good at preventing upper bound conflicts between plugins (JENKINS-51068). In order to work it around, this repository uses pom.xml as an input instead of defining plugins in YAML directly. So it is possible to ensure that the plugin set is OK just by running mvn clean verify.

As a second advantage, usage of pom.xml allows using Dependabot to track dependencies and to propose updates. This dependency management is quite dangerous, because there is no CI created for this repository so far.

Debugging Jenkinsfile Runner

To debug the execution, you can pass the JFR_LOCAL_WORKSPACE=true environment variable to the image. It will make the builder to execute Pipeline directly

Limitations

This project has just started, so it has some downsides being compared to the runtime Pipeline Development instance here. All of the limitations below can be improved in the future.

• A custom fork of Jenkins Pipeline Library is needed to run it
  • Follow jenkins-infra/pipeline-library#78
• ci.jenkins.io-runner is a single-container package with only 1 executor
• Only JDK8 and JDK11 are provided in the image
• Windows steps are not supported
• Docker-in-Docker is not supported. Steps like runATH() and runPCT() will not work
• The runner uses the recent Debian version, and hence it is affected by SUREFIRE-1588. Plugin POM 3.28 or above should be used to run the build successfully
• Docker image is pretty big. It bundles two versions of JDK for starters, but it needs some optimization in any case.