Symfony 4使用Docker容器生成SQLSTATE[HY000][2002]连接被拒绝

我有2个Docker容器，使用以下配置：

version: '2'

volumes:
  db_data: {}

services:

  db:
    container_name: database-mysql-5.7
    build:
      context: ./docker/db/
    ports:
      - "3321:3306"
    volumes:
      - db_data:/var/lib/mysql

  web:
    container_name: apache-symfony-4
    build:
      context: ./docker/web/
    image: php
    links:
      - db
    depends_on:
      - db
    ports:
      - "8021:80"
    volumes:
      - ./app/:/var/www/symfony

我可以从本地主机Mac OS连接到db容器，也可以从web容器连接到db容器并成功执行sql语句。此外，当我执行web容器时，我可以成功地执行条令：migrations:diff命令

但是，当我尝试运行以下代码时：

$User = $this->getDoctrine()
                ->getRepository(User::class)
                ->findAll();

我收到以下错误：

An exception occurred in driver: SQLSTATE[HY000] [2002] Connection refused

octrine\DBAL\Exception\ConnectionException:
An exception occurred in driver: SQLSTATE[HY000] [2002] Connection refused

  at vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php:108
  at Doctrine\DBAL\Driver\AbstractMySQLDriver->convertException('An exception occurred in driver: SQLSTATE[HY000] [2002] Connection refused', object(PDOException))
     (vendor/doctrine/dbal/lib/Doctrine/DBAL/DBALException.php:176)
  at Doctrine\DBAL\DBALException::wrapException(object(Driver), object(PDOException), 'An exception occurred in driver: SQLSTATE[HY000] [2002] Connection refused')
     (vendor/doctrine/dbal/lib/Doctrine/DBAL/DBALException.php:161)
  at Doctrine\DBAL\DBALException::driverException(object(Driver), object(PDOException))
     (vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOMySql/Driver.php:47)

这是我的.env文件的内容

# This file is a "template" of which env vars need to be defined for your application
# Copy this file to .env file for development, create environment variables when deploying to production
# https://symfony.com/doc/current/best_practices/configuration.html#infrastructure-related-configuration

###> symfony/framework-bundle ###
APP_ENV=dev
APP_SECRET=7c2deaf7464ad40b484d457e02a56918
#TRUSTED_PROXIES=127.0.0.1,127.0.0.2
#TRUSTED_HOSTS=localhost,example.com
###< symfony/framework-bundle ###

###> symfony/swiftmailer-bundle ###
# For Gmail as a transport, use: "gmail://username:password@localhost"
# For a generic SMTP server, use: "smtp://localhost:25?encryption=&auth_mode="
# Delivery is disabled by default via "null://localhost"
MAILER_URL=null://localhost
###< symfony/swiftmailer-bundle ###

###> doctrine/doctrine-bundle ###
# Format described at http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html#connecting-using-a-url
# For an SQLite database, use: "sqlite:///%kernel.project_dir%/var/data.db"
# Configure your db driver and server_version in config/packages/doctrine.yaml
DATABASE_URL=mysql://hereswhatsontap:####@db:####/hereswhatsontap
###< doctrine/doctrine-bundle ###

尝试使用根用户名/密码也失败

好的，最后一个附加数据我保证：

在Symfony的/public文件夹中执行以下代码可以正常工作

<?php
$dsn = 'mysql:host=db;dbname=hereswhatsontap;';
$username = 'hereswhatsontap';
$password = '####';
$options = array(
    PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8',
);

$dbh = new PDO($dsn, $username, $password, $options);

$sql = "SELECT * from user";
$statement = $dbh->prepare($sql);
$statement->execute();
$users = $statement->fetchAll(2);
print_r($users);
?>

---

这个问题是由于我完全不了解集装箱之间的通信方式造成的

web容器和db容器基本上位于它们自己的“vpn”网络上，这意味着web容器可以直接与db通信，然后根据我的配置使用内部端口3306

因此，从.env文件的数据库URL值中删除作为外部端口的端口就是答案

---

该死

非常感谢您的评论，它为我节省了更多的研究时间。我只想为Docker中的新手添加一条信息，即如果您想获得容器IP，可以运行以下命令，这样您就不必只使用inspect在整个配置转储中查找：

docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' YOURCONTAINERID

---

再次感谢

你能复制你的.env配置吗？在这个问题中添加了我的.env文件4个小时，这个答案也解决了我的问题，哦，上帝，谢谢！

docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' YOURCONTAINERID