Integration of cflinuxfs5 stack

What is this issue about?

The cflinuxfs5 stack is now available, based on Ubuntu 24.04 "Noble Numbat". Application developers will need to move to this stack before cflinuxfs4 leaves support.

In this issue we want to track the integration of cflinuxfs5 into the cf-deployment release and validation process.

cflinuxfs5 stack

• cflinuxfs5-release

cflinuxfs5 support for buildpacks shipped with cf-deployment (according to release notes):

• java-buildpack
• dotnet-core-buildpack
• nodejs-buildpack
• python-buildpack
• go-buildpack
• ruby-buildpack
• staticfile-buildpack
• php-buildpack
• nginx-buildpack
• r-buildpack
• binary-buildpack

Integration of cflinuxfs5 into CATs and cf-deployment

• experimental ops file to ship cflinuxfs5 and supported buildpacks as opt-in
• experimental ops file to make cflinuxfs5 default stack
• run CATS against cflinuxfs5 (attach leaf downstream job to e.g. "fresh-cats" which runs CATs on fs5)
• promote cflinuxfs5 ops files (could be skipped if we integrate the ops files directly into cf-deployment.yml)
• rollout step 1 (make cflinuxfs5 the default)
• rollout step 2 (remove cflinuxfs4 leftovers)

Start by reviewing cf-deployment.yml and the promoted cflinuxfs5 ops files, then compare the remaining rollout checklist with the existing CATS validation process. The work is done when cflinuxfs5 is the default stack and cflinuxfs4 leftovers have been removed, with the deployment and validation flow still passing.