Can't link symfony app container to mysql container

Question

I have a tow running containers one with symfony app and the other is mysql database server:

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                               NAMES
99d17c328612        sbc/gestcom:1.0     "docker-php-entrypoi…"   18 hours ago        Up 2 minutes        0.0.0.0:4400->80/tcp                musing_moser
97dafcfb4acd        mysql               "docker-entrypoint.s…"   18 hours ago        Up 2 minutes        0.0.0.0:3306->3306/tcp, 33060/tcp   suspicious_brattain

I linked mysql container to symfony contianer like so:

docker container run -d -p 4400:80 --link suspicious_brattain:db sbc/gestcom:1.0

suspicious_brattain: is the name of the mysql container
sbc/gestcom:1.0: is the name of the image I built that contains my symfony app (with apache, php and pdo driver needed to work with mysql)
Now when I access the symfony app container to run doctrine:database:create I get this exception:

In AbstractMySQLDriver.php line 93:

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

This is parameters.yml file:

parameters:
    database_host: 127.0.0.1
    database_port: 3306
    database_name: my_database
    database_user: root
    database_password: root

Of course I gave root as password for mysql image when running it like so:

docker container run -e MYSQL_ROOT_PASSWORD=root -d mysql

And to be sure that the symfony container is linked to mysql container this what I get when I inspect the symfony container:

...
"Links": [
    "/suspicious_brattain:/musing_moser/db"
],
...

As you can see they are connected, however I still unable to create my database using symfony command and I get Connection refused!

Answer 1

You shouldn't be trying to connect on 127.0.0.1, but to db.

When linking containers, a /etc/hosts entry is created in the container to make configuration more convenient.