DOCKER + PDO：SQLSTATE [HY000] [2002]无法通过套接字'/var/run/mysqld/mysqld.sock'连接到本地MySQL服务器（2）

Question

When trying to connect a dockerized PHP-Application to a MySQL-Container, I get the following error: SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

Dockerfile:

FROM tutum/apache-php
RUN rm -fr /app
COPY . /app

ENV DB_HOST=192.168.99.100
ENV DB_NAME=azk
ENV DB_USER=root
ENV DB_PW=my-secret-pw

If I do not use PDO, the connection works, so there musst be something wrong with PDO, but I have no idea what...

Answer 1

PDO uses unix socket connection instead of tcp. see the answer how to force using tcp connection.

in your case probably you don't applied ENV DB_HOST to php application config file. (you can use getenv('DB_HOST') function)