KEP-0003: Technical implementation strategy for Kubeflow Hub rename

[chambridge]

Description

Introduces KEP-0003 defining the technical implementation strategy for renaming "Kubeflow Model Registry" to "Kubeflow Hub" following community approval of KEP-907. The KEP establishes Kubeflow Hub as an umbrella project name grouping AI asset management components (Model Registry, Catalog, and future capabilities) while maintaining stable component names to minimize disruption.

Key Technical Decisions:

• Repository rename: kubeflow/model-registry → kubeflow/hub
• Container registry hard cutover to ghcr.io/kubeflow/hub/* for new versions
• Go developers encouraged to migrate to Kubeflow SDK
• API paths remain unchanged for backwards compatibility
• Python SDK package name stays "model-registry" (component-specific)
• Kubernetes service names unchanged (component names remain accurate)
• Addition of /catalog/ API alias alongside /model_catalog/

Design Approach:

• Zero breaking changes to API paths and Python SDK
• Hard cutover for container images with clear migration timeline
• Component-by-component impact analysis with mitigation strategies
• Comprehensive user stories covering all stakeholder groups
• Phased graduation criteria (Alpha → Beta → Stable)
• Detailed alternatives analysis with rationale for decisions

The KEP follows proper KEP format with complete sections for summary, motivation, proposal, design details, test plan, graduation criteria, drawbacks, alternatives, and references.

Merge criteria:

• All the commits have been signed-off (To pass the DCO check)

• The commits have meaningful messages
• Automated tests are provided as part of the PR for major new functionalities; testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work.
• Code changes follow the kubeflow contribution guidelines.
• For first time contributors: Please reach out to the Reviewers to ensure all tests are being run, ensuring the label ok-to-test has been added to the PR.

If you have UI changes

• The developer has added tests or explained why testing cannot be added.
• Included any necessary screenshots or gifs if it was a UI change.
• Verify that UI/UX changes conform the UX guidelines for Kubeflow.

[google-oss-prow]

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