feat(health): add /healthz endpoint (#26)

src/quartermaster/main.py

@@ -6,6 +6,7 @@ from fastapi import FastAPI
 from fastapi.staticfiles import StaticFiles
 
 from quartermaster.routes import router
+from quartermaster.routes_health import router as health_router
 from quartermaster.routes_month import router as month_router
 
 STATIC_DIR = Path(__file__).parent / "static"
@@ -14,6 +15,7 @@ STATIC_DIR = Path(__file__).parent / "static"
 def create_app() -> FastAPI:
     app = FastAPI(title="Quartermaster", version="0.1.0")
     app.mount("/static", StaticFiles(directory=str(STATIC_DIR)), name="static")
+    app.include_router(health_router)
     app.include_router(router)
     app.include_router(month_router)
     return app

src/quartermaster/routes_health.py

@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+import logging
+
+from fastapi import APIRouter, Depends
+from fastapi.responses import JSONResponse
+from sqlalchemy import text
+from sqlalchemy.orm import Session
+
+from quartermaster.db import get_session
+
+logger = logging.getLogger("quartermaster.health")
+
+router = APIRouter()
+
+
+@router.get("/healthz")
+def healthz(db: Session = Depends(get_session)) -> JSONResponse:
+    try:
+        db.execute(text("SELECT 1"))
+    except Exception as exc:
+        logger.warning(
+            "healthz check failed",
+            extra={"event": "healthz_failed", "error_class": type(exc).__name__},
+        )
+        return JSONResponse(
+            status_code=503,
+            content={"status": "error", "detail": type(exc).__name__},
+        )
+    return JSONResponse(status_code=200, content={"status": "ok"})

tests/test_health.py

@@ -0,0 +1,7 @@
+from __future__ import annotations
+
+
+def test_healthz_returns_ok(client):
+    response = client.get("/healthz")
+    assert response.status_code == 200
+    assert response.json() == {"status": "ok"}