app/logger.py

@@ -0,0 +1,102 @@
+"""
+Centralized logging configuration using Loguru.
+
+Outputs structured JSON to stdout (INFO/WARNING) and stderr (ERROR/CRITICAL).
+Designed for Docker + Grafana Loki / Promtail.
+
+Usage:
+    from logger import logger, setup_logging
+
+    setup_logging()          # call once at application entry point
+    logger.info("message")
+"""
+
+import os
+import sys
+import logging
+from dotenv import load_dotenv
+from loguru import logger
+
+
+def get_log_level() -> str:
+    """Reads LOG_LEVEL or log_level from .env or environment, defaults to 'INFO'."""
+    load_dotenv()
+    level = os.getenv("LOG_LEVEL") or os.getenv("log_level") or "INFO"
+    return level.strip().upper()
+
+
+# ── Stdout / stderr filters ───────────────────────────────────────────────────
+
+def _stdout_filter(record: dict) -> bool:
+    """Pass DEBUG / INFO / WARNING to stdout."""
+    return record["level"].no < logging.ERROR
+
+
+def _stderr_filter(record: dict) -> bool:
+    """Pass ERROR / CRITICAL to stderr."""
+    return record["level"].no >= logging.ERROR
+
+
+# ── Stdlib → Loguru bridge ────────────────────────────────────────────────────
+
+class InterceptHandler(logging.Handler):
+    """Redirect all stdlib logging calls into Loguru."""
+
+    def emit(self, record: logging.LogRecord) -> None:
+        try:
+            level = logger.level(record.levelname).name
+        except ValueError:
+            level = record.levelno
+
+        frame, depth = sys._getframe(6), 6
+        while frame and frame.f_code.co_filename == logging.__file__:
+            frame = frame.f_back
+            depth += 1
+
+        logger.opt(depth=depth, exception=record.exc_info).log(
+            level, record.getMessage()
+        )
+
+
+# ── Public setup function ─────────────────────────────────────────────────────
+
+def setup_logging(level: str | None = None) -> None:
+    """
+    Configure Loguru sinks and intercept all stdlib loggers.
+    Call once at the very start of the application entry point.
+    """
+    if not level:
+        level = get_log_level()
+    else:
+        level = level.strip().upper()
+
+    logger.remove()  # remove default sink
+
+    common: dict = {
+        "level": level,
+        "serialize": True,   # JSON output
+        "backtrace": False,
+        "diagnose": False,
+    }
+
+    # stdout — DEBUG / INFO / WARNING
+    logger.add(sys.stdout, filter=_stdout_filter, **common)
+
+    # stderr — ERROR / CRITICAL
+    logger.add(sys.stderr, filter=_stderr_filter, **{**common, "level": "ERROR"})
+
+    # Redirect all stdlib loggers (uvicorn, motor, aiogram, aio_pika …)
+    logging.basicConfig(handlers=[InterceptHandler()], level=0, force=True)
+
+    # Suppress noisy third-party loggers — we handle HTTP access via middleware
+    _quiet = {
+        "uvicorn.access": logging.WARNING,  # replaced by our middleware
+        "motor":          logging.WARNING,
+        "aio_pika":       logging.WARNING,
+        "aiormq":         logging.WARNING,
+    }
+    for name, lvl in _quiet.items():
+        _lib_logger = logging.getLogger(name)
+        _lib_logger.handlers = [InterceptHandler()]
+        _lib_logger.setLevel(lvl)
+        _lib_logger.propagate = False

app/main.py

@@ -1,6 +1,5 @@
 import os
 import secrets
-import logging
 
 import uvicorn
 import asyncio
@@ -16,9 +15,10 @@ from schemas.base_schemas import Card
 from mongo_worker import MongoWorker
 from rabbit_worker import RabbitWorker
 from tools.base_moderation import moderate_text
+from logger import logger, setup_logging
+from middleware import RequestLoggingMiddleware
 
-
-logger = logging.getLogger(__name__)
+setup_logging()
 load_dotenv()
 disable_docs = os.getenv("DISABLE_DOCS", "true").lower() == "true"
 
@@ -56,6 +56,7 @@ config = SecurityConfig(
 guard_deco = SecurityDecorator(config)
 
 app.add_middleware(SecurityMiddleware, config=config)
+app.add_middleware(RequestLoggingMiddleware)
 app.state.guard_decorator = guard_deco
 mongo_worker = MongoWorker()
 _rabbit_worker: Optional[RabbitWorker] = None
@@ -84,6 +85,7 @@ async def verify_moderation_secret(
 @app.on_event("startup")
 async def startup_event():
     await mongo_worker.create_indexes()
+    logger.info("Application started on :5000")
 
 
 @app.get("/check_user", status_code=200)
@@ -170,7 +172,7 @@ async def add_card(
         try:
             await get_rabbit_worker().send_to_moderation(card)
         except Exception as exc:
-            logger.error("Failed to send card %s to moderation queue: %s", card.card_id, exc)
+            logger.error("Failed to send card {} to moderation queue: {}", card.card_id, exc)
 
         return BaseResponse(result=card)
     response.status_code = status.HTTP_400_BAD_REQUEST
@@ -277,7 +279,7 @@ async def get_comments(
 
 
 async def main():
-    config = uvicorn.Config("main:app", host="0.0.0.0", port=5000, log_level="info")
+    config = uvicorn.Config("main:app", host="0.0.0.0", port=5000, log_level="warning")
     server = uvicorn.Server(config)
     await server.serve()
 

app/middleware.py

@@ -0,0 +1,62 @@
+"""
+HTTP request/response logging middleware for FastAPI.
+
+Normal requests (2xx/3xx):
+    INFO  — method, path, query_params, status_code, duration_ms
+
+Error responses (4xx):
+    WARNING — all above + request_body (truncated to 1000 chars)
+
+Server errors (5xx):
+    ERROR — all above + request_body (truncated to 1000 chars)
+"""
+
+import time
+
+from starlette.middleware.base import BaseHTTPMiddleware
+from starlette.requests import Request
+from starlette.responses import Response
+
+from logger import logger
+
+_BODY_METHODS = frozenset({"POST", "PUT", "PATCH"})
+_BODY_MAX_LEN = 1000
+
+
+class RequestLoggingMiddleware(BaseHTTPMiddleware):
+    async def dispatch(self, request: Request, call_next) -> Response:
+        start = time.perf_counter()
+
+        # Read body only for methods that carry a payload
+        body: str | None = None
+        if request.method in _BODY_METHODS:
+            raw = await request.body()
+            body = raw.decode(errors="replace")[:_BODY_MAX_LEN]
+
+        response = await call_next(request)
+
+        duration_ms = round((time.perf_counter() - start) * 1000, 1)
+        status = response.status_code
+
+        base_fields = {
+            "method": request.method,
+            "path": request.url.path,
+            "query": str(request.query_params) or None,
+            "status": status,
+            "duration_ms": duration_ms,
+        }
+
+        if status >= 500:
+            logger.bind(**base_fields, request_body=body).error(
+                "{method} {path} → {status} ({duration_ms}ms)", **base_fields
+            )
+        elif status >= 400:
+            logger.bind(**base_fields, request_body=body).warning(
+                "{method} {path} → {status} ({duration_ms}ms)", **base_fields
+            )
+        else:
+            logger.bind(**base_fields).info(
+                "{method} {path} → {status} ({duration_ms}ms)", **base_fields
+            )
+
+        return response

app/mongo_worker.py

@@ -1,5 +1,4 @@
 import os
-import logging
 
 import motor.motor_asyncio
 
@@ -10,9 +9,7 @@ from pymongo import ReturnDocument
 
 from schemas.base_schemas import User, Visited, Card, Comment
 from schemas.api_schemas import BaseResponse
-
-
-logger = logging.getLogger(__name__)
+from logger import logger
 
 
 class MongoWorker:
@@ -25,7 +22,12 @@ class MongoWorker:
             password=os.getenv('MONGO_PASS'),
             serverSelectionTimeoutMS=5000,
             connectTimeoutMS=5000,
+            maxPoolSize=50,
+            minPoolSize=5,
+            maxIdleTimeMS=60000,
+            waitQueueTimeoutMS=5000
         )
+        logger.info("MongoDB connection established.")
         self.db = self.client["data"]
         self.users_data = self.db["users"]
         self.visited_data = self.db["visited"]
@@ -58,6 +60,7 @@ class MongoWorker:
             registration_date=datetime.now().isoformat(),
         )
         await self.users_data.insert_one(new_user.model_dump())
+        logger.debug("User added: user_id={}, username={}", user_id, username)
         return new_user
 
     async def get_user(self, user_id: int) -> User:
@@ -130,6 +133,7 @@ class MongoWorker:
             creation_date=datetime.now().isoformat(),
         )
         await self.game_data.insert_one(new_card.model_dump())
+        logger.debug("Card created by API: card_id={}, author_id={}", new_card.card_id, author_id)
         return new_card
 
     async def add_card_by_base_model(self, new_card: Card) -> Optional[Card]:
@@ -138,7 +142,7 @@ class MongoWorker:
             await self.game_data.insert_one(new_card.model_dump())
             return new_card
         except Exception as exc:
-            logger.error("Failed to insert card: %s", exc)
+            logger.error("Failed to insert card: {}", exc)
             raise
 
     async def accept_card(self, card_id: int) -> BaseResponse:
@@ -152,14 +156,18 @@ class MongoWorker:
             return_document=ReturnDocument.AFTER,
         )
         if not result:
+            logger.debug("Attempted to accept non-existent card: card_id={}", card_id)
             return BaseResponse(result="Card doesn't exist", error=True)
+        logger.debug("Card accepted: card_id={}", card_id)
         return BaseResponse(result=Card.model_validate(result))
 
     async def reject_card(self, card_id: int) -> BaseResponse:
         """Rejects a card: deletes it from the database."""
         result = await self.game_data.delete_one({"card_id": card_id})
         if result.deleted_count == 0:
+            logger.debug("Attempted to reject non-existent card: card_id={}", card_id)
             return BaseResponse(result="Card doesn't exist", error=True)
+        logger.debug("Card rejected and deleted: card_id={}", card_id)
         return BaseResponse(result=f"Card {card_id} rejected and deleted")
 
     async def select_choice(self, card_id: int, choice: str) -> BaseResponse:
@@ -206,6 +214,7 @@ class MongoWorker:
             {"user_id": user_id},
             {"$push": {"liked_card_ids": card_id}},
         )
+        logger.debug("Card liked: card_id={}, user_id={}", card_id, user_id)
         return BaseResponse(result=True, error=False)
 
     async def dislike_card(self, card_id: int, user_id: int) -> BaseResponse:
@@ -227,6 +236,7 @@ class MongoWorker:
             {"user_id": user_id},
             {"$push": {"disliked_card_ids": card_id}},
         )
+        logger.debug("Card disliked: card_id={}, user_id={}", card_id, user_id)
         return BaseResponse(result=True, error=False)
 
 
@@ -253,6 +263,7 @@ class MongoWorker:
         if not updated_user:
             return BaseResponse(result="Difficulty adding comment_id to user", error=True)
 
+        logger.debug("Comment added: comment_id={}, card_id={}, author_id={}", new_comment.comment_id, card_id, user_id)
         return BaseResponse(result=new_comment)
 
     async def get_comments(self, card_id: int) -> BaseResponse:

app/rabbit_worker.py

@@ -1,7 +1,6 @@
 import os
 import json
 import asyncio
-import logging
 from typing import Callable, Awaitable
 
 import aio_pika
@@ -9,9 +8,7 @@ from aio_pika.abc import AbstractIncomingMessage
 from dotenv import load_dotenv
 
 from schemas.base_schemas import Card
-
-
-logger = logging.getLogger(__name__)
+from logger import logger
 
 
 class RabbitWorker:
@@ -20,9 +17,11 @@ class RabbitWorker:
         self.url = (
             f"amqp://{os.getenv('RABBIT_USER')}:{os.getenv('RABBIT_PASS')}"
             f"@{os.getenv('RABBIT_HOST')}:{os.getenv('RABBIT_PORT')}"
-        )   
+        )
+        logger.info("RabbitWorker connection established.")
 
     async def send_to_moderation(self, card: Card) -> None:
+        logger.debug("Preparing to send card {} to moderation queue...", card.card_id)
         connection = await aio_pika.connect_robust(self.url)
         async with connection:
             channel = await connection.channel()
@@ -34,7 +33,8 @@ class RabbitWorker:
                 ),
                 routing_key="moderation",
             )
-            logger.info("Card %s sent to moderation queue", card.card_id)
+            logger.debug("Card {} successfully published to moderation queue", card.card_id)
+            logger.info("Card {} sent to moderation queue", card.card_id)
 
     async def consume_moderation(
         self,
@@ -55,7 +55,7 @@ class RabbitWorker:
                         card = Card.model_validate(card_data)
                         await callback(card)
                     except Exception as exc:
-                        logger.error("Error processing moderation message: %s", exc)
+                        logger.error("Error processing moderation message: {}", exc)
 
             await queue.consume(on_message)
 

app/requirements.txt

@@ -5,4 +5,5 @@ python-dotenv==1.0.1
 uvicorn==0.34.0
 aio-pika==10.0.1
 aiogram==3.18.0
-aiohttp==3.11.18
+aiohttp==3.11.18
+loguru==0.7.3

app/tg_bot.py

@@ -11,7 +11,6 @@ When a button is pressed, the bot calls protected endpoints
 import os
 import json
 import asyncio
-import logging
 from datetime import datetime
 
 import aiohttp
@@ -21,18 +20,17 @@ from aiogram.types import CallbackQuery, InlineKeyboardButton, InlineKeyboardMar
 
 from schemas.base_schemas import Card
 from rabbit_worker import RabbitWorker
+from logger import logger, setup_logging
 
 
 load_dotenv()
-logging.basicConfig(level=logging.INFO)
-logger = logging.getLogger(__name__)
+setup_logging()
 
 # ── Configuration ──────────────────────────────────────────────
 BOT_TOKEN = os.getenv("TG_BOT_TOKEN")
 ADMIN_CHAT_ID = int(os.getenv("TG_ADMIN_CHAT_ID", "0"))
 API_BASE_URL = os.getenv("API_BASE_URL", "http://localhost:5000")
 MODERATION_SECRET = os.getenv("MODERATION_SECRET", "change-me-in-production")
-
 bot = Bot(token=BOT_TOKEN)
 dp = Dispatcher()
 rabbit = RabbitWorker()
@@ -52,7 +50,7 @@ async def _get_author_username(author_id: int) -> str:
                     if username:
                         return f"@{username}"
     except Exception as exc:
-        logger.warning("Failed to fetch username for %s: %s", author_id, exc)
+        logger.warning("Failed to fetch username for {}: {}", author_id, exc)
     return str(author_id)
 
 
@@ -97,7 +95,7 @@ async def send_card_to_admin(card: Card) -> None:
         reply_markup=keyboard,
         parse_mode="HTML",
     )
-    logger.info("Sent card %s to admin chat", card.card_id)
+    logger.info("Sent card {} to admin chat", card.card_id)
 
 
 # ── Calling protected API endpoints ──────────────────────────
@@ -131,7 +129,7 @@ async def on_accept(callback: CallbackQuery) -> None:
         parse_mode="HTML",
     )
     await callback.answer("Карточка принята!")
-    logger.info("Card %s accepted by admin", card_id)
+    logger.info("Card {} accepted by admin", card_id)
 
 
 @dp.callback_query(F.data.startswith("reject:"))
@@ -148,7 +146,7 @@ async def on_reject(callback: CallbackQuery) -> None:
         parse_mode="HTML",
     )
     await callback.answer("Карточка отклонена!")
-    logger.info("Card %s rejected by admin", card_id)
+    logger.info("Card {} rejected by admin", card_id)
 
 # ── aiogram Lifecycle hooks ────────────────────────────────────
 _rabbit_task: asyncio.Task | None = None