Objective:

Track upstream Tekton proposal to add opt-in automatic PVC cleanup for the stable workspaces coscheduling mode.

Context:

Users running PipelineRuns with volumeClaimTemplate in stable workspaces mode accumulate PVCs after completion, causing increased storage costs and manual cleanup burden. Alpha modes (pipelineruns, isolate-pipelinerun) auto-delete PVCs, but there's no stable/production-ready option.

An upstream proposal has been submitted to add an opt-in annotation (tekton.dev/auto-cleanup-pvc: "true") to enable PVC cleanup on PipelineRun completion. The implementation is straightforward (~20 lines of code), reusing existing cleanup logic from alpha modes. Fully backward compatible.

Upstream References:

• Proposal: https://github.com/tektoncd/pipeline/issues/9284
• Original issue: https://github.com/tektoncd/pipeline/issues/5776
• TEP-0135: https://github.com/tektoncd/community/blob/main/teps/0135-coscheduling-pipelinerun-pods.md

Acceptance Criteria:

• [ ] Monitor upstream discussion on the proposal
• [ ] If approved, evaluate for product inclusion
• [ ] If implemented upstream, consider backport or include in next version

Technical Notes:

The cleanup logic already exists in PurgeFinalizerAndDeletePVCForWorkspace() used by alpha modes. The proposal just needs to call it conditionally for workspaces mode based on annotation presence.