Docker Compose中Python应用连接MySQL容器的端口配置指南

config = {
    'host': 'mysql',
    'port': '3307',   # 错误：应使用容器内部端口
    'user': 'user',
    'password': 'password',
    'database': 'db',
}

config = {
    'host': 'mysql',
    'port': '3306',   # 正确：使用MySQL容器内部监听的端口
    'user': 'user',
    'password': 'password',
    'database': 'db',
}

version: '3'

services:
  mysql:
    image: mysql:latest
    ports:
      - "3307:3306" # 宿主机3307映射到容器3306
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_DATABASE: db
      MYSQL_USER: user
      MYSQL_PASSWORD: password
    networks:
      - sql_network
    volumes:
      - /mysql_data:/var/lib/mysql

  python_app:
    build: .
    ports:
      - "5000:5000"
    networks:
      - sql_network
    depends_on:
      - mysql

networks:
  sql_network:

import mysql.connector
import logging
import time

logger = logging.getLogger(__name__)

config = {
    'host': 'mysql',  # Docker Compose服务名称，解析为容器IP
    'port': '3306',   # MySQL容器内部监听的端口
    'user': 'user',
    'password': 'password',
    'database': 'db',
}

def create_tables():
    logger.info("Entering create tables method from dbservice")
    connection = None # 初始化connection变量
    try:
        # 增加连接重试机制，以应对MySQL容器启动慢的情况
        retries = 5
        for i in range(retries):
            try:
                connection = mysql.connector.connect(**config)
                logger.info("Successfully connected to MySQL.")
                break
            except mysql.connector.Error as err:
                logger.warning(f"Attempt {i+1}/{retries}: Could not connect to MySQL: {err}. Retrying in 5 seconds...")
                time.sleep(5)

        if not connection or not connection.is_connected():
            raise Exception("Failed to establish MySQL connection after multiple retries.")

        cursor = connection.cursor()

        # 检查'emails'表是否已存在
        cursor.execute("SHOW TABLES LIKE 'emails'")
        table_exists = cursor.fetchone()

        if not table_exists:
            cursor.execute(
                '''
                CREATE TABLE emails (
                id INT PRIMARY KEY AUTO_INCREMENT,
                created TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
                email VARCHAR(255) NOT NULL,
                verified BOOLEAN NOT NULL,
                flatType VARCHAR(255) NOT NULL,
                streetName VARCHAR(255) NOT NULL,
                blkFrom INT NOT NULL,
                blkTo INT NOT NULL,
                lastSent TIMESTAMP,
                token VARCHAR(255))
                ''')
            connection.commit()
            logger.info("Table 'emails' created successfully.")
        else:
            logger.info("Table 'emails' already exists.")

    except Exception as e:
        logger.error(f"Unable to create tables due to {e}")
    finally:
        if connection and connection.is_connected():
            connection.close()
            logger.info("MySQL connection closed.")

# ... 其他导入和应用初始化代码 ...

# time.sleep(10) # 这种硬编码的等待方式不够健壮
create_tables() # 结合dbService中的重试机制会更可靠
# ... 其他应用逻辑 ...