CakePHP容器连接Google SQL Proxy容器失败求助

代理容器状态 #

代理已配置凭据并正常启动，日志如下：

2025-01-29 12:31:44 2025/01/29 18:31:44 Authorizing with the credentials file at "/path/to/service-account-key.json"
2025-01-29 12:31:44 2025/01/29 18:31:44 [project-name:us-central1:instance-name] Listening on [::]:5432
2025-01-29 12:31:44 2025/01/29 18:31:44 The proxy has started successfully and is ready for new connections!

CakePHP数据库配置（app.php） #

'Datasources' => [
        'default' => [
            'className' => Connection::class,
            'driver' => Mysql::class,
            'persistent' => false,
            'host' => '[::]:5432', // 已尝试过 'localhost:5432'
            'username' => 'myusername',
            'password' => 'mypassword',
            'database' => 'mydatabasename',
            'encoding' => 'utf8mb4',
            'timezone' => 'UTC',
            'cacheMetadata' => true,
            'flags' => [],
            'log' => false,
            'quoteIdentifiers' => false,
        ]

代理容器启动命令 #

docker run -d -v F:\local\path\to\service-account-key.json:/path/to/service-account-key.json -p 127.0.0.1:5432:5432 gcr.io/cloud-sql-connectors/cloud-sql-proxy:2.14.3 --address 0.0.0.0 --port 5432 --credentials-file /path/to/service-account-key.json project-name:us-central1:instance-name

错误信息 #

Database CakePHP is NOT able to connect to the database.
Connection to Mysql could not be established: SQLSTATE[HY000] [2002] Connection refused

代理容器未记录任何连接尝试，直接访问localhost:5432时容器会接受连接，但返回无效响应（非HTTP请求）。

1. 修复Docker网络连通性 #

CakePHP容器和代理容器默认不在同一Docker网络，无法通过localhost或[::]互相访问：

• 新建专用Docker网络：

  docker network create cloud-sql-network
  

• 启动代理容器时加入该网络，同时给容器命名方便访问：

  docker run -d --name cloud-sql-proxy --network cloud-sql-network -v F:\local\path\to\service-account-key.json:/path/to/service-account-key.json -p 127.0.0.1:5432:5432 gcr.io/cloud-sql-connectors/cloud-sql-proxy:2.14.3 --address 0.0.0.0 --port 5432 --credentials-file /path/to/service-account-key.json project-name:us-central1:instance-name
  

• 启动CakePHP容器时也加入同一网络：

  docker run --network cloud-sql-network [你的CakePHP容器启动命令]
  

• 修改CakePHP的host配置为代理容器名称：cloud-sql-proxy:5432

2. 修正端口与数据库驱动不匹配问题 #

Cloud SQL的MySQL默认端口为3306，你当前代理监听的5432是PostgreSQL默认端口，驱动与端口不匹配会导致连接失败：

• 调整代理启动命令的端口为3306：

  docker run -d --name cloud-sql-proxy --network cloud-sql-network -v F:\local\path\to\service-account-key.json:/path/to/service-account-key.json -p 127.0.0.1:3306:3306 gcr.io/cloud-sql-connectors/cloud-sql-proxy:2.14.3 --address 0.0.0.0 --port 3306 --credentials-file /path/to/service-account-key.json project-name:us-central1:instance-name
  

• 同步修改CakePHP的host配置为：cloud-sql-proxy:3306

3. 验证代理与数据库权限 #

• 确认所用服务账号已分配Cloud SQL Client角色，拥有访问目标Cloud SQL实例的权限
• 用本地MySQL客户端直接测试代理连通性，排除代理本身问题：

  mysql -h 127.0.0.1 -P 3306 -u myusername -p mydatabasename
  

  如果本地能连接，说明代理正常，问题仅存在于CakePHP容器的网络配置。

内容的提问来源于stack exchange，提问作者Me JW Crouch