Skip to main content
U.S. flag

An official website of the United States government

Deprecation of cflinuxfs3

March 28, 2023

Important Update - 4/27/2023 : The original instructions indicated that a cf restage will move apps to cflinuxfs4. It does not, you have to cf push -s STACK_NAME your application.

Important Update - 5/16/2023 : The deprecation dates for cflinuxfs3 have been pushed out from the original date of 5/10/2023 to the dates now seen in the document.

Deprecation of cflinuxfs3

Ubuntu 22.04 stack (cflinuxfs4) buildpacks are here and Ubuntu 18.04 (cflinuxfs3) are retiring: Test and upgrade your apps now!

The base OS image used by your applications is called a “stack”. The stack we’ve provided to date is called cflinuxfs3, and it’s based on Ubuntu 18.04 LTS, released originally in mid 2018 with continuous security updates since then. cflinuxfs4 is a new OS image based on Ubuntu 22.04 LTS, and it’s already available for your use. We’ll be making cflinuxfs4 the default stack in on April 27th. In addition, Ubuntu 18.04 will likely no longer receive security updates in May, so we will stop supporting cflinuxfs3 in May 10th.

Who is impacted?

If you push your Cloud Foundry applications as Docker containers with cf push --docker-image , these changes do not impact you.

However, most customers deploy their applications using buildpacks, and their apps don’t have any dependency on the particular OS version that runs them. If that describes you, this upgrade will probably be a miraculous non-event… You can request the new stack at your next cf push with a stack parameter and carry on as you always have.

However, there may be exceptions! For example, you may have used the apt-buildpack to ensure that a particular library or utility is installed when your app is deployed. In that case, you might run into problems if the location or name of that dependency has changed between Ubuntu 18.04 and Ubuntu 22.04. You’ll also want to be sure to use the newest v0.3.0 version of this release which supports cflinuxfs4.

What should you do now?

If you are using buildpacks to build your apps, you should try out the new cflinuxfs4 stack before we make it the default on April 27th. Check out the Cloud Foundry stack docs to see how. To change your stack and re-push your app, run the following command:

cf push MY-APP -s cflinuxfs4

What happens if your testing fails?

If you find problems, you can continue using the deprecated cflinuxfs3 stack until you’ve resolved any issues and are ready to transition your apps. After April 27th you can use the following command to temporarily use the older stack:

cf push MY-APP -s cflinuxfs3

However, this is only a temporary solution because cflinuxfs3 will be removed as an option after May 10th. Plan to make the switch soon so you’re not up against the deadline!

Checking your progress

Option 1 - Use the Dashboard UI for individual apps

You can use the Stratos UI dashboard at and navigate to “Applications > select an app > Build info” to see what stack version each of your applications is using. If it says “cflinuxfs3” you still need to upgade your stack by repushing your application with the stack paramter.

Option 2 - Use the CF cli for all apps

To quickly see the which of your applications are still using cflinuxfs3, the following script can be used. Note that it requires you to be logged in with the CF cli, target an org and have jq installed:

cf curl "/v3/apps?per_page=5000&include=space.organization" | jq '(.included.spaces | INDEX(.guid)) as $spaces | (.included.organizations | INDEX(.guid)) as $orgs | [ .resources[] | select( == "cflinuxfs3") | {app: .name, org:$orgs[$spaces[]].name ,space: $spaces[].name , lifecycle} ]'

(Note of thanks to the folks at SAP who created that command at )


When What Available Stacks Default Stack
March 23 Roll out all cflinuxfs4 buildpacks cflinuxfs3, cflinuxfs4 cflinuxfs3
March 23 - April 27 Developers test and update apps to use cflinuxfs4 cflinuxfs3, cflinuxfs4 cflinuxfs3
April 27 Support ends for cflinuxfs3. All new apps pushed will use cflinuxfs4 by default, existing apps will need to be migrated. cflinuxfs3, cflinuxfs4 cflinuxfs4
April 27 - June 29 Explicitly opt to use cflinuxfs3 if you need more time cflinuxfs3, cflinuxfs4 cflinuxfs4
June 29 cflinuxfs3 buildpacks will be retired from the platform, apps needing cflinuxfs3 buildpacks will need to reference them via URL on the cf push cflinuxfs3, cflinuxfs4 cflinuxfs4
Sept 28 Only cflinuxfs4 will be available, this is a breaking change for apps not updated to use cflinuxfs4 cflinuxfs4 cflinuxfs4

Platform Buildpacks

Buildpack Name Version Exists for Both Stacks
staticfile_buildpack v1.6.0 Yes
java_buildpack v4.54 Yes
ruby_buildpack v1.9.3 Yes
dotnet_core_buildpack v2.4.8 Yes
nodejs_buildpack v1.8.7 Yes
go_buildpack v1.10.6 Yes
python_buildpack v1.8.8 Yes
php_buildpack v4.6.1 Yes
binary_buildpack v1.1.3 Yes
nginx_buildpack v1.2.1 Yes
r_buildpack v1.2.0 Yes

An official website of the U.S. General Services Administration

Looking for U.S. government information and services?