decomposer: generate deliverable files for Define the service contract and project architecture for the FastAPI endpoint monitoring service.; Implement the typed monitor CRUD API and concurrency-safe in-memory state according to the service design.; Implement secure on-demand endpoint checks with status updates, latency measurement, robust error handling, and redacted structured logs.; Add operational API endpoints and environment-driven runtime configuration to the monitoring service.; Create automated tests for the monitoring service.; Package the service with Docker and developer documentation.; Validate the complete project.

app/main.py

@@ -1,105 +1,96 @@
 from contextlib import asynccontextmanager
-from typing import AsyncIterator, cast
 from uuid import UUID
 
 import httpx
-from fastapi import Depends, FastAPI, HTTPException, Request, Response, status
+from fastapi import FastAPI, HTTPException, Response, status
 
-from app.checker import EndpointChecker, UnsafeTarget
+from .checker import EndpointChecker
-from app.config import Settings, get_settings
+from .config import get_settings
-from app.logging import configure_logging
+from .logging_config import configure_logging
-from app.models import (CheckResult, CheckStatus, HealthResponse, Monitor,
+from .models import Monitor, MonitorCreate, MonitorUpdate, ProbeResponse, StatusResponse
-                        MonitorCreate, MonitorUpdate)
+from .store import MonitorStore
-from app.store import MonitorStore, Snapshot
+
+settings = get_settings()
+configure_logging(settings.log_level)
 
 
-def error(status_code: int, code: str, message: str) -> HTTPException:
+@asynccontextmanager
-    return HTTPException(status_code=status_code,
+async def lifespan(app: FastAPI):
-                         detail={"code": code, "message": message})
+    app.state.store = MonitorStore()
-
+    app.state.ready = True
-
-def create_app(settings: Settings | None = None) -> FastAPI:
-    config = settings or get_settings()
-    configure_logging(config.log_level)
-
-    @asynccontextmanager
-    async def lifespan(application: FastAPI) -> AsyncIterator[None]:
-        application.state.store = MonitorStore()
     async with httpx.AsyncClient() as client:
-            application.state.checker = EndpointChecker(client, config)
+        app.state.checker = EndpointChecker(client, settings.request_timeout_seconds, settings.max_redirects, settings.max_response_bytes)
         yield
+    app.state.ready = False
 
-    application = FastAPI(title=config.app_name, version="1.0.0", lifespan=lifespan)
 
-    def store(request: Request) -> MonitorStore:
+app = FastAPI(title=settings.app_name, version="1.0.0", lifespan=lifespan)
-        return cast(MonitorStore, request.app.state.store)
 
-    async def existing(monitor_id: UUID, repository: MonitorStore = Depends(store)) -> Snapshot:
-        snapshot = await repository.snapshot(monitor_id)
-        if snapshot is None:
-            raise error(404, "monitor_not_found", "Monitor not found")
-        return snapshot
 
-    @application.post("/v1/monitors", response_model=Monitor,
+def missing() -> HTTPException:
-                      status_code=status.HTTP_201_CREATED)
+    return HTTPException(status_code=404, detail="monitor not found")
-    async def create_monitor(data: MonitorCreate,
-                             repository: MonitorStore = Depends(store)) -> Monitor:
-        return await repository.create(data)
 
-    @application.get("/v1/monitors", response_model=list[Monitor])
-    async def list_monitors(repository: MonitorStore = Depends(store)) -> list[Monitor]:
-        return await repository.list()
 
-    @application.get("/v1/monitors/{monitor_id}", response_model=Monitor)
+@app.post("/api/v1/monitors", response_model=Monitor, status_code=status.HTTP_201_CREATED)
-    async def get_monitor(snapshot: Snapshot = Depends(existing)) -> Monitor:
+async def create_monitor(data: MonitorCreate) -> Monitor:
-        return snapshot.monitor
+    return await app.state.store.create(data)
 
-    @application.patch("/v1/monitors/{monitor_id}", response_model=Monitor)
+
-    async def update_monitor(monitor_id: UUID, data: MonitorUpdate,
+@app.get("/api/v1/monitors", response_model=list[Monitor])
-                             repository: MonitorStore = Depends(store)) -> Monitor:
+async def list_monitors() -> list[Monitor]:
-        item = await repository.update(monitor_id, data)
+    return await app.state.store.list()
+
+
+@app.get("/api/v1/monitors/{monitor_id}", response_model=Monitor)
+async def get_monitor(monitor_id: UUID) -> Monitor:
+    item = await app.state.store.get(monitor_id)
     if item is None:
-            raise error(404, "monitor_not_found", "Monitor not found")
+        raise missing()
     return item
 
-    @application.delete("/v1/monitors/{monitor_id}", status_code=204)
-    async def delete_monitor(monitor_id: UUID,
-                             repository: MonitorStore = Depends(store)) -> Response:
-        if not await repository.delete(monitor_id):
-            raise error(404, "monitor_not_found", "Monitor not found")
-        return Response(status_code=204)
 
-    @application.post("/v1/monitors/{monitor_id}/checks", response_model=CheckResult)
+@app.put("/api/v1/monitors/{monitor_id}", response_model=Monitor)
-    async def run_check(request: Request, snapshot: Snapshot = Depends(existing),
+async def update_monitor(monitor_id: UUID, data: MonitorUpdate) -> Monitor:
-                        repository: MonitorStore = Depends(store)) -> CheckResult:
+    item = await app.state.store.update(monitor_id, data)
-        checker = cast(EndpointChecker, request.app.state.checker)
+    if item is None:
-        try:
+        raise missing()
-            check_status = await checker.check(str(snapshot.monitor.url))
+    return item
-        except UnsafeTarget as exc:
-            blocked = CheckStatus(state="error", error=str(exc))
-            await repository.apply_status(snapshot.monitor.id, snapshot.revision, blocked)
-            raise error(400, "unsafe_target", str(exc)) from exc
-        applied = await repository.apply_status(
-            snapshot.monitor.id, snapshot.revision, check_status
-        )
-        return CheckResult(monitor_id=snapshot.monitor.id, status_applied=applied,
-                           **check_status.model_dump())
-
-    @application.get("/v1/monitors/{monitor_id}/status", response_model=CheckStatus)
-    async def current_status(snapshot: Snapshot = Depends(existing)) -> CheckStatus:
-        return snapshot.monitor.status
-
-    @application.get("/healthz", response_model=HealthResponse)
-    async def health() -> HealthResponse:
-        return HealthResponse(status="ok")
-
-    @application.get("/readyz", response_model=HealthResponse)
-    async def ready(request: Request) -> HealthResponse:
-        if not hasattr(request.app.state, "store") or not hasattr(request.app.state, "checker"):
-            raise error(503, "not_ready", "Service dependencies are not initialized")
-        return HealthResponse(status="ready")
-
-    return application
 
 
-app = create_app()
+@app.delete("/api/v1/monitors/{monitor_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_monitor(monitor_id: UUID) -> Response:
+    if not await app.state.store.delete(monitor_id):
+        raise missing()
+    return Response(status_code=status.HTTP_204_NO_CONTENT)
+
+
+@app.post("/api/v1/monitors/{monitor_id}/check", response_model=Monitor)
+async def check_monitor(monitor_id: UUID) -> Monitor:
+    item = await app.state.store.get(monitor_id)
+    if item is None:
+        raise missing()
+    result = await app.state.checker.check(str(monitor_id), str(item.url))
+    updated = await app.state.store.record(monitor_id, result)
+    if updated is None:
+        raise missing()
+    return updated
+
+
+@app.get("/api/v1/monitors/{monitor_id}/status", response_model=StatusResponse)
+async def monitor_status(monitor_id: UUID) -> StatusResponse:
+    item = await app.state.store.get(monitor_id)
+    if item is None:
+        raise missing()
+    return StatusResponse(id=item.id, status=item.status, checked_at=item.checked_at or item.created_at, latency_ms=item.latency_ms or 0, http_status=item.http_status, error=item.error)
+
+
+@app.get("/healthz", response_model=ProbeResponse)
+async def health() -> ProbeResponse:
+    return ProbeResponse(status="ok")
+
+
+@app.get("/readyz", response_model=ProbeResponse)
+async def ready() -> ProbeResponse:
+    if not getattr(app.state, "ready", False):
+        raise HTTPException(status_code=503, detail="not ready")
+    return ProbeResponse(status="ready")