What's Changing​

When you deploy Java applications on Cloud.gov, the Java buildpack provides your JVM and other dependencies. The Cloud Foundry Java buildpack team has completed a major rewrite, version 5, which removes legacy code and introduces breaking changes to how Java apps are built and deployed.

Current status:

• Default buildpack: v4.76.0 (March 2025)
• New buildpack: v5.0.x series (in testing)
• Timeline: v4.76.0 will remain the Cloud.gov default until v5.1.0 GA release, date not yet known

Why You Should Act Now​

The Cloud Foundry team is actively addressing issues in the new buildpack, but they can only fix bugs they know about. By testing your applications now, you'll help identify issues before the upgrade becomes the default, ensuring a smoother transition for your team and the entire Cloud.gov community.

Step 1: Review the relevant documentation​

The following documents detail the changes, and provide additioanl context:

• 5.0.0 Release notes
• Cloud Foundry Community RFC

Step 2: Test Your Java Applications​

We strongly recommend that all Cloud.gov customers test their Java applications with the new buildpack. Early testing gives you time to address any compatibility issues before the migration, and may reveal bugs that need to be fixed upstream with Cloud Foundry.

Option A: Test Using the cf push Command​

Run the following command to deploy your app with the 5.0.2 buildpack (update to 5.0.3, etc., as those become available)

cf push MY_APP --buildpack https://github.com/cloudfoundry/java-buildpack/releases/download/v5.0.2/java-buildpack-cflinuxfs4-v5.0.2.zip

Option B: Test Using Your manifest.yml File​

Add the 5.0.2 buildpack specification to your manifest file:

    ...
    buildpacks:
      - https://github.com/cloudfoundry/java-buildpack/releases/download/v5.0.2/java-buildpack-cflinuxfs4-v5.0.2.zip
   ...

Then deploy as usual with cf push.

Pro tip: Test in a non-production environment first to validate behavior without undue risk.

Step 3: Report Any Issues You Encounter​

If you discover compatibility problems or unexpected behavior during testing:

• For buildpack-specific issues: Report them directly to the Cloud Foundry Java buildpack team at https://github.com/cloudfoundry/java-buildpack/issues
• Need help reporting an issue? Open a support request and our team will assist you in documenting and escalating the problem.

When reporting issues, include:

• Your application's Java version
• Relevant error messages or logs
• Steps to reproduce the problem
• Expected vs. actual behavior

Alternative: Pin Your Buildpack Version (If Needed)​

While we recommend adopting the v5.x buildpack as soon as it's generally available, you can temporarily pin your applications to an older version if you need more time to migrate. Use the same syntax shown above in the testing section to specify your preferred buildpack version.

Note: Pinning to older versions means you won't receive the latest security updates and features, so plan to upgrade as soon as feasible.

Timeline and Next Steps:

1. Now through v5.1.0 GA release: Test your applications and report issues
2. When v5.1.0 is released: Cloud.gov will make v5.x the default buildpack
3. After the transition: Continue monitoring your applications and update any version pins

Questions? Contact Cloud.gov support for assistance.