Add optional DB write probe to readiness endpoint

backend/main.py

@@ -51,12 +51,16 @@ def healthz():
 
 
 @app.get("/readyz")
-def readyz():
+def readyz(write_test: bool = False):
     try:
         with db() as c:
             with c.cursor() as cur:
                 cur.execute("select 1 as ok")
                 cur.fetchone()
+                if write_test:
+                    cur.execute("create temporary table if not exists readyz_probe(id int)")
+                    cur.execute("insert into readyz_probe(id) values (1)")
+                    cur.execute("truncate table readyz_probe")
     except Exception:
         raise HTTPException(503, "Database not ready")
     return {"ok": True}