Migrate Flask based user APIs to Fastapi

[Fury0508]

This PR migrates the remaining user endpoints from Connexion to FastAPI as part of #56730.

What's Changed

New endpoints in api_fastapi/routes/users.py:

• GET /fab/v1/users - List users with pagination and ordering
• GET /fab/v1/users/{username} - Get a single user by username
• PATCH /fab/v1/users/{username} - Update user with update_mask support
• DELETE /fab/v1/users/{username} - Delete a user

New datamodels in api_fastapi/datamodels/users.py:

• UserPatchBody - Request model for partial updates (all fields optional)
• UserCollectionResponse - Response model for paginated user list

New service methods in api_fastapi/services/users.py:

• get_user() - Retrieve single user
• get_users() - List users with pagination/ordering
• update_user() - Partial update with update_mask support
• delete_user() - Remove user

Tests added:

• Route tests for all new endpoints (success, 403, 404, 422 cases)
• Service layer tests covering all methods
• Datamodel tests for UserPatchBody and UserCollectionResponse

Notes

• Follows existing patterns from roles.py implementation
• update_mask uses comma-separated string format (consistent with roles endpoint)
• All 125 tests pass locally

closes #60946

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

Generated-by: Claude following the guidelines

Claude was used for:

• Code review and suggestions for implementation patterns
• Writing test cases for routes, services, and datamodels
• Debugging test environment setup issues

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[henry3260]

Thanks for the PR! I just have one question:

It seems user_endpoint.py hasn't been migrated to FastAPI yet, but the commit message says it has. Did we miss this file?

[Fury0508]

Thanks for the PR! I just have one question:

It seems user_endpoint.py hasn't been migrated to FastAPI yet, but the commit message says it has. Did we miss this file?

Thanks for the question!

The new FastAPI endpoints have been created in api_fastapi/routes/users.py (you can see them in the "Files changed" tab):

• GET /fab/v1/users
• GET /fab/v1/users/{username}
• PATCH /fab/v1/users/{username}
• DELETE /fab/v1/users/{username}

The old Connexion file (api_endpoints/user_endpoint.py) is intentionally kept for now. This follows the same pattern as the roles migration (PR #58023) - create new FastAPI endpoints first, then remove old Connexion files in a separate cleanup PR after all migrations are complete.

The migration approach is:

1. Create new FastAPI endpoints (this PR)
2. Remove old Connexion endpoints (separate cleanup after Replace connexion with fast-api: role_and_permission_endpoint.py #60944, Replace connexion with fast-api: initialization, constants, exceptions, schemas. #60945 are done)

[vincbeck]

LGTM

[henry3260]

Try running prek run --all-files locally, it should fix the formatting issues :)

[Fury0508]

Try running prek run --all-files locally, it should fix the formatting issues :)

Thanks! Ran pre-commit run --all-files locally and pushed the fixes. Hopefully CI passes now 🤞

[Fury0508]

@vincbeck CI has 2 failing checks:

1. UI E2E tests - I only modified backend API code, no frontend changes

2. Compat 3.0.6 - The error "Status code 204 must not have a response body" occurs in ALL FAB FastAPI route tests:

   • test_login.py (3 errors) - not modified by me
   • test_roles.py (23 errors) - not modified by me
   • test_users.py (22 errors) - my changes

The error happens during test setup, suggesting a TestClient compatibility issue with Airflow 3.0.6, not my code.

Could you confirm if these are known issues? Happy to investigate further if needed.

[henry3260]

I guess the CI failed because returning None results in a null response body, but HTTP 204 responses must not have a body. Please return an empty Response object instead.

[henry3260]

Thanks for the fix. LGTM.

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.