mysql - "Can' t connect to local MySQL server"in docker-compose

Question

我有 Laravel 应用程序和 MySQL，我正在尝试使用 docker-compose 在 Docker 中运行它。但是当应用程序尝试连接数据库时，它会抛出:

PDOException in Connector.php line 55: SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

我的 docker-compose.yml:

load_balancer:
image: tutum/haproxy
links:
    - web
ports:
    - "80:80"

cache:
    image: redis

db:
    image: mysql
    environment:
        MYSQL_ROOT_PASSWORD: Q1w2e3r4t5
        MYSQL_DATABASE: regappbase

web:
    image: andrewmclagan/nginx-hhvm
    links:
        - db
        - cache
    volumes: 
        - ./:/var/www
    environment:
        - APP_ENV=local
        - DB_DATABASE=regappbase
        - DB_PASSWORD=Q1w2e3r4t5
        - VIRTUAL_HOST=laravel.local

我的.env:

APP_ENV=production
APP_DEBUG=true
APP_KEY=SomeRandomString
APP_URL=http://laravel.local

DB_CONNECTION=mysql
DB_HOST=localhost
DB_PORT=3306
DB_DATABASE=regappbase
DB_USERNAME=root
DB_PASSWORD=Q1w2e3r4t5

CACHE_DRIVER=file
SESSION_DRIVER=file
QUEUE_DRIVER=sync

REDIS_HOST=laravel.local
REDIS_PASSWORD=null
REDIS_PORT=6379

MAIL_DRIVER=smtp
MAIL_HOST=mailtrap.io
MAIL_PORT=2525

Answer 1

默认情况下，Mysql 与“localhost”的连接尝试通过本地机器上存在的套接字进行连接。您的 DB_HOST 应该是链接的容器名称“db”。

来自MYSQL docs :

On Unix, MySQL programs treat the host name localhost specially, in a way that is likely different from what you expect compared to other network-based programs. For connections to localhost, MySQL programs attempt to connect to the local server by using a Unix socket file. This occurs even if a --port or -P option is given to specify a port number. To ensure that the client makes a TCP/IP connection to the local server, use --host or -h to specify a host name value of 127.0.0.1, or the IP address or name of the local server. You can also specify the connection protocol explicitly, even for localhost, by using the --protocol=TCP option. For example: