Can't connect to a remote mysql database from php within a docker container

Question

My setup: docker (php, mysql, nginx and some other)

My Problem: I can not connect to a remote mysql database within the php docker container

php Example:

    try
    {
        $this->live['pdo'] = new PDO(
            'mysql:host='.$_ENV['DB_REMOTE_HOST'].';port='.$_ENV['DB_REMOTE_PORT'].';dbname='.$_ENV['DB_REMOTE_DATABASE'],
            $_ENV['DB_REMOTE_USERNAME'],
            $_ENV['DB_REMOTE_PASSWORD']
        );
        $this->live['pdo']->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $this->live['pdo']->exec("SET NAMES utf8");
        $this->live['pdo']->exec("SET CHARACTER SET utf8");
    }
    catch (PDOException $e)
    {
        echo $e->getMessage();
        exit;
    }

my.env

DB_REMOTE_HOST = "5.9.xxx.xx"
DB_REMOTE_PORT = 3306
DB_REMOTE_DATABASE = "somedb"
DB_REMOTE_USERNAME = "someuser"
DB_REMOTE_PASSWORD = "xxxxxx"

part of my docker-compose.yml

php:
build:
  context: .
  dockerfile: ./php/Dockerfile
  args:
    ENVIRONMENT: ${ENVIRONMENT}
container_name: php
restart: "unless-stopped"
ports:
  - "9000"
  - "9006"
  - "3306:3306"
volumes:
  - ./app/myapp.com:/var/www/html:cached
working_dir: /var/www/html
networks:
  - my_network

So when i try to run the php example above, i am getting:

SQLSTATE[HY000] [1045] Access denied for user 'someuser'@'85.110.xxx.xx' (using password: YES

85.110.xxx.xx is the acutal ip address i am getting with my macbook on https://whatsmyip.com/

thats wierd for me, because the ip i try to reach is 5.9.xxx.xx . The mysql user, the database and the password are correct i triple checked it. I can even login with sequel. I already tried to make the port 3306 public for the php container, doesn't change anything.

I will be very thankful, if anyone can help me on this.

Answer 1

In MySQL a user is defined by a username AND an IP address from which they connect. There is the exceptional "%" meaning every IP is accepted. So if your MySQL user isn't defined on the server like 'someuser'@'85.110.xxx.xx' or 'someuser'@'%' , the server will deny access to you.