Merge pull request 'Improved database connection and logging:' (#2) from feature/improved-db-handling into main

Reviewed-on: #2

src/db.py

@@ -1,59 +1,72 @@
 import mysql.connector
+from mysql.connector import pooling, Error
 import threading
 from secret_handler import return_credentials
 import os
 import time
-import sys
+from logger_handler import setup_logger
 
 db_username = return_credentials("/etc/secrets/db_username")
 db_password = return_credentials("/etc/secrets/db_password")
 db_host = os.getenv("SERVICE_RR_DB_HOST","localhost")
 db_database = os.getenv("SERVICE_RR_DB_HOST_DATABASE","app")
 
+logger = setup_logger(__name__)
+
+
 MAX_RETRIES = 5
 RETRY_DELAY = 5
+HEALTHCHECK_INTERVAL = 60
 
 MYSQL_CONFIG = {
 	"host": db_host,
 	"user": db_username,
 	"password": db_password,
-	"database": db_database
+	"database": db_database,
+	"connection_timeout": 10
 }
 
+
 _pool_lock = threading.Lock()
 _connection_pool = None
+_health_thread = None
+_stop_healthcheck = threading.Event()
 
 
 def create_connection_pool():
 	global _connection_pool
-	for attempt in range(1, MAX_RETRIES+1):
+	with _pool_lock:
+		if _connection_pool is not None:
+			return
+	for attempt in range (1,MAX_RETRIES+1):
 		try:
-			print(f"[MySQL] Attempt {attempt} to connect...")
-			pool  = mysql.connector.pooling.MySQLConnectionPool(
-				pool_name="mypool",
+			logger.info(f"[MySQL] Attempt {attempt} to connect...")
+			pool = pooling.MySQLConnectionPool(
+				pool_name="royalroadPool",
 				pool_size=5,
 				pool_reset_session=True,
 				**MYSQL_CONFIG
 			)
 			with _pool_lock:
 				_connection_pool = pool
-			print("[MySQL] Connection pool created successfully.")
+			logger.info("[MySQL] Pool created", extra={"pool_name": pool.pool_name})
 			return
-		except mysql.connector.Error as e:
-			print(f"[MySQL] Attempt {attempt} failed: {e}")
+
+		except Error as e:
+			logger.warning(f"[MySQL] Attempt {attempt} failed: {e}")
 			if attempt < MAX_RETRIES:
 				time.sleep(RETRY_DELAY)
-	print(f"[MySQL] Failed to connect after {MAX_RETRIES} attempts — exiting.")
-	sys.exit(1)
 
+	logger.critical(f"[MySQL] Failed to connect after {MAX_RETRIES} attempts.")
+	raise RuntimeError("MySQL pool initialization failed")
 
 def close_connection_pool():
 	global _connection_pool
 	with _pool_lock:
 		if _connection_pool:
 			_connection_pool = None
-			print("[MySQL] Connection pool closed.")
-
+			logger.info("[MySQL] Connection pool closed")
+	_stop_healthcheck.set()
 
 def get_connection_pool():
 	global _connection_pool
@@ -62,18 +75,46 @@ def get_connection_pool():
 			create_connection_pool()
 	return _connection_pool
 
-
 def get_db():
 	pool = get_connection_pool()
+	conn = pool.get_connection()
+
 	try:
-		conn = pool.get_connection()
-		if not conn.is_connected():
-			conn.reconnect(attempts=MAX_RETRIES, delay=RETRY_DELAY)
-	except Exception:
+		conn.ping(reconnect=True, attempts=3, delay=1)
+	except Error as e:
+		logger.warning(f"[MySQL] Connection dead, recreating pool: {e}")
 		create_connection_pool()
 		pool = get_connection_pool()
 		conn = pool.get_connection()
+
 	try:
 		yield conn
 	finally:
-		conn.close()
+		if conn and conn.is_connected():
+			conn.close()
+
+def _pool_healthcheck():
+	while not _stop_healthcheck.is_set():
+		time.sleep(HEALTHCHECK_INTERVAL)
+		with _pool_lock:
+			pool = _connection_pool
+		if not pool:
+			continue
+		try:
+			conn = pool.get_connection()
+			conn.ping(reconnect=True, attempts=3, delay=1)
+			conn.close()
+			logger.debug("[MySQL] Pool healthcheck OK.")
+		except Error as e:
+			logger.warning(f"[MySQL] Pool healthcheck failed: {e}")
+			create_connection_pool()
+
+
+def start_healthcheck_thread():
+	global _health_thread
+	if _health_thread and _health_thread.is_alive():
+		return
+	_stop_healthcheck.clear()
+	_health_thread = threading.Thread(target=_pool_healthcheck, daemon=True)
+	_health_thread.start()
+	logger.info("[MySQL] Healthcheck thread started.")

src/logger_handler.py

@@ -0,0 +1,13 @@
+import logging
+
+def setup_logger(name: str) -> logging.Logger:
+	logger = logging.getLogger(name)
+	if not logger.handlers:
+		handler = logging.StreamHandler()
+		formatter = logging.Formatter(
+			'%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+		)
+		handler.setFormatter(formatter)
+		logger.addHandler(handler)
+		logger.setLevel(logging.DEBUG)
+	return logger

src/main.py

@@ -1,15 +1,16 @@
 from fastapi import FastAPI, Depends, HTTPException, Response, Request
 import uvicorn
 from contextlib import asynccontextmanager
-from db import get_db, create_connection_pool, close_connection_pool
-import logging
+from db import get_db, create_connection_pool, close_connection_pool, start_healthcheck_thread
+from logger_handler import setup_logger
 from feed_handler import grab_latest_chapter_information
 from send_notification import send_notification
 from metrics_server import REQUEST_COUNTER
 import asyncio
 
 
-logger = logging.getLogger(__name__)
+logger = setup_logger(__name__)
+
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
@@ -18,6 +19,9 @@ async def lifespan(app: FastAPI):
 	logger.info("Creating MySQL connection pool...")
 	create_connection_pool()
 
+	start_healthcheck_thread()
+	logger.info("MySQL healthcheck thread started.")
+
 	yield
 	logger.info("Closing MySQL connection pool...")
 	close_connection_pool()

src/send_notification.py

@@ -4,12 +4,12 @@ from fastapi import HTTPException
 from secret_handler import return_credentials
 import os
 import time
-import logging
+from logger_handler import setup_logger
 
 
 backend_api_url=os.getenv("BACKEND_API_URL","localhost:8101/internal/receive-notifications")
 api_key= return_credentials("/etc/secrets/api_key")
-logger = logging.getLogger(__name__)
+logger = setup_logger(__name__)
 
 
 def send_notification(title:str,

src/uvicorn_logging_config.py

@@ -0,0 +1,39 @@
+LOGGING_CONFIG = {
+	"version": 1,
+	"disable_existing_loggers": False,
+	"formatters": {
+		"default": {
+			"format": "%(asctime)s - %(levelname)s - %(name)s - %(message)s",
+			"datefmt": "%Y-%m-%d %H:%M:%S",
+		}
+	},
+	"handlers": {
+		"default": {
+			"class": "logging.StreamHandler",
+			"formatter": "default",
+			"stream": "ext://sys.stdout"
+		}
+	},
+	"loggers": {
+		"": {  # root logger
+			"handlers": ["default"],
+			"level": "INFO",
+			"propagate": False
+		},
+		"uvicorn": {
+			"handlers": ["default"],
+			"level": "INFO",
+			"propagate": False
+		},
+		"uvicorn.error": {
+			"handlers": ["default"],
+			"level": "INFO",
+			"propagate": False
+		},
+		"uvicorn.access": {
+			"handlers": ["default"],
+			"level": "INFO",
+			"propagate": False
+		}
+	}
+}