ResourceStatusSource + route

[aldbr]

Description

Wire the data models #837 and caching infrastructure #838 together: implement ResourceStatusSource(CacheableSource) that reads from ResourceStatusDB and serves resource status through a new config route.

Scope

1. ResourceStatusSource: a CacheableSource subclass that:

   • Reads from ResourceStatusDB (Site + Resource status tables)
   • Translates DB status values (Active/Degraded/Banned/...) to the binary Pydantic models (AllowedStatus/BannedStatus)
   • Implements latest_revision() — e.g. hash of current status snapshot, or max DateEffective/LastCheckTime
   • Implements read_raw() — returns the full status dict per resource type and VO

2. Route: new endpoint under the config router:

   /config/resource-status/storage?vo={inferred_from_credentials} -> dict[str, StorageElementStatus]
   

   Equivalent endpoints for compute and site status.

3. Access policy: any authenticated user can read (similar to current config endpoint being @open_access, but scoped to the user's VO).

4. Integration tests: verify end-to-end flow from DB data to API response, including HTTP caching headers (ETag / 304 Not Modified).

Technical details

• ResourceStatusSource lives in diracx-core/src/diracx/core/config/ or a new diracx-core/src/diracx/core/rss/ package
• VO is inferred from the client's token — no need to expose all VOs
• HTTP caching (ETag, Last-Modified, 304) should reuse the same pattern as the config endpoint
• Dependency injection: ResourceStatusSource needs access to ResourceStatusDB — design the wiring so it fits the existing DI patterns

Reference

• Chris's route proposal: #790 comment
• Config router pattern: diracx-routers/src/diracx/routers/configuration.py
• DI patterns: diracx-routers/src/diracx/routers/dependencies.py

Acceptance criteria

• ResourceStatusSource(CacheableSource) reads from ResourceStatusDB and produces Pydantic status models
• Route serves storage/compute/site status per VO
• HTTP caching headers (ETag, 304 Not Modified)
• Access policy: authenticated users, scoped to their VO
• Integration tests covering the full read path

[aldbr]

ddev meeting: we mention legacy adaptor, but we won't have any here