TASK-004: Replace module-level mutable runtime flags in service layer with
injected state holder, eliminating hidden global state and improving testability
and synchronization boundaries.
Changes:
- Create JailServiceState dataclass in app/utils/runtime_state.py to hold
backend capability cache and synchronization lock
- Add JailServiceState as a field in RuntimeState (with default_factory)
- Remove module-level _backend_cmd_supported and _backend_cmd_lock from
jail_service.py
- Refactor _check_backend_cmd_supported() to accept state parameter
- Inject JailServiceState into list_jails() and _fetch_jail_summary() via
parameters
- Add get_jail_service_state() dependency provider in app/dependencies.py
- Add JailServiceStateDep type alias for router injection
- Update jails router to receive and pass state to service functions
- Update all tests to use jail_service_state fixture and pass state to functions
- Remove duplicate _MAX_PAGE_SIZE constant definition
- Document mutable state management in Backend-Development.md
- Update Architecture.md to describe JailServiceState and state nesting pattern
Benefits:
- Eliminates global mutable state and associated race conditions
- Makes state visible to callers (not hidden in module scope)
- Enables test isolation (each test gets fresh state)
- Prepares codebase for multi-worker deployments (state can be extracted to
shared backend)
- Synchronization boundaries are now explicit (state.get_backend_cmd_lock())
Compliance:
- All tests pass (17 passed in TestListJails, TestGetJail, TestLockInitialization)
- No ruff linting errors
- Type-safe: JailServiceState properly typed with asyncio.Lock, bool | None
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Lukas
2e221f6852