This page is a collaborative entry point for developer resources about developing and testing Jenkins to run on Java 11.
This page is not designed to receive status updates for user-facing issues. But you are more than welcome to check and report such issues so that they show on the dedicated Known Java 11 Compatibility issues wiki page.
- How to
- Run Jenkins using Java 11
- Develop and test your plugin for running on Java 11
- Release an experimental plugin version specifically for Java 11
- Run Plugin Compat Tester (aka PCT) using Java 11
- Run Acceptance Test Harness (aka ATH) using Java 11
- Jenkins Core known issues with Java 11
- Known developer tools issues
Run Jenkins using Java 11
Develop and test your plugin for running on Java 11
As a part of JEP-211, we request all plugins to remain compatible with Java 8 for now. But you may still need to run the tests with Java 11 so that you can verify the plugin's behavior. It is possible to pass "jvm" and extra Java properties to Maven Surefire plugin to just run tests, but it is easier to actually build & test plugins with JDK 11. Jenkins development tools have been updated to support that:
- For non-experimental releases you should always build the plugins with java.level=8
plugin-pom:3.29+(changelog). Versions before 3.29 contain some updates to be able to build and test your plugins using JDK 11
- Plugins will be able to compile successfully with JDK 11 if and only if Jenkins Core version (jenkins.version) is above 2.138+
- You can update Jenkinsfile to run tests with Java 11. To workaround the Jenkins core requirement, a full configuration matrix may be used in buildPlugin():
Some potential pitfalls to remember about:
- The existing "mvn hpi:run" command will not work correctly on Java 11 unless Java modules are downloaded and passed to the environment ( JENKINS-54807 - Maven HPI Plugin or Plugin POM should automatically set up Java 11 environment for hpi:run Resolved )
- If you use Mockito/PowerMock in your plugin tests, you may need to update to the recent versions with Java 11 support
- In some cases FindBugs may crash in some cases ( JENKINS-53692 - Plugin POM: FindBugs sometimes fails on Java 11 Resolved ), workarounds may be needed
See the "Known developer tools issues" for more known issues in Plugin POM and Jenkins plugins.
Make sure your plugin is tested in Continuous Integration on Java 8 and Java 11 at the same time
Since this addition, it is now recommended that you use the following configuration in your plugin:
By default, this will build your plugin:
- on the default configuration, extracted from your pom.xml
- on Jenkins 2.164.1 using a JDK 8
- on Jenkins 2.164.1 using a JDK 11
All this both on Windows and Linux.
Release an experimental plugin version specifically for Java 11
Although we request all plugins to remain compatible with Java 8, in some cases it may be reasonable to release an experimental version for Java 11 early adopters.
In order to do that, we provide an Experimental Update Center for Java 11. Since Jenkins 2.155, if you run using Jenkins versions with Java 11 preview, Jenkins and Jenkins Docker plugins.txt installer (e.g. "workflow-support:experimental") will default to this experimental update center. It allows Java 11 early adopters to get patches without requiring deploying snapshots manually:
In order to do an experimental release for Java 11, all the following steps must be performed:
- Develop the Java 11 code in a feature branch (e.g. "java11-support") so that it does not impact main release line
- Add an "alpha" or "beta" marker to the version of your experimental plugin
- Update to plugin-pom:3.29+ so your plugin embeds the new minimum version of Java requirement in its manifest
- Set the plugin.minimumJavaVersion property in your pom.xml to 11 (see https://github.com/jenkinsci/plugin-pom/blob/master/CHANGELOG.md#329)
If if you forget about any of the bullets above, the update may impact Java 8 users. The long-term solution is already on its way, but is not delivered yet. Follow JENKINS-55048 - Jenkins core should check plugin Minimum Java requirements in Update Center metadata Resolved if you are interested.
Run Plugin Compat Tester (aka PCT) using Java 11
Documented in the PCT repository: https://github.com/jenkinsci/plugin-compat-tester#running-pct-with-custom-java-versions
Current status of many plugins (please comment there to get access, or send an email if you tested another opensource plugin).
Run Acceptance Test Harness (aka ATH) using Java 11
Documented on the ATH repository: https://github.com/jenkinsci/acceptance-test-harness/blob/master/docs/JAVA11.md
Jenkins Core known issues with Java 11
If you hit this issue JENKINS-55150 - [jenkins-dev] jenkins-dev:run no longer has hot reload after 2.152 Resolved about live reloading of resources in Jenkins, the current workaround is "mvn org.jenkins-ci.tools:maven-jenkins-dev-plugin:9.4.5.v20170502-jenkins-1:run"
Known developer tools issues
Please add known issues here. The preferred way is to create or find the associated JIRA in the Jenkins Issue Tracker, and add the
"java11-devtools-compatibility". Then the issue it will automatically show up in the list below.
If you cannot create a JIRA issue, please still feel free to add notes about your findings below.