Wrong credentials when connecting to Docker MySQL container - docker

Question

New to docker and I'm using laradock to set up my environment with a Craft CMS project. I'm able to get it installed and set up, however I'm have an issue when trying to connect to the MySQL container that laradock creates from the docker-compose.yml file.
Here's the db related portion in my docker-compose.yml
mysql:
build:
context: ./mysql
args:
- MYSQL_DATABASE=homestead
- MYSQL_USER=homestead
- MYSQL_PASSWORD=secret
- MYSQL_ROOT_PASSWORD=root
volumes:
- mysql:/var/lib/mysql
ports:
- "3306:3306"
Within my craft/config/db.php file, I have the following settings:
return array(
'.dev' => array(
'tablePrefix' => 'craft',
'server' => 'mysql',
'database' => 'homestead',
'user' => 'homestead',
'password' => 'secret',
),
);
However, I'm getting a Craft can’t connect to the database with the credentials in craft/config/db.php error.
My question is - when docker creates the MySQL container, I'm assuming it uses the credentials in the docker-compose.yml file to create and allow access to that database. If so, as long as my container is running and my credentials from my db.php file match with the credentials in the docker-compose.yml file, shouldn't it connect?
If I wanted to update the credentials in the MySQL container, can I simply update the values in both files and run docker-compose up -d mysql?
Thanks!

Answer 1

I have run in kind of similar issue recently because the containers were started in a "random" order. Maybe this is your issue too don't know for sure.
In a brief this is my case:
- two containers php-fpm and mysql.
- Running docker-compose up -d --build --no-cache build everything but php-fpm finished first so by then mysql was doing some stuff for get service ready
- php-fpm application couldn't connect to MySQL server because wasn't ready
The solution use the new Docker Compose version and use 2.1 on the docker-compose.yml. Here is my working example:
version: '2.1'
services:
php-fpm:
build:
context: docker/php-fpm
depends_on:
db:
condition: service_healthy
db:
image: mariadb
healthcheck:
test: "exit 0"
environment:
MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
MYSQL_DATABASE: ${MYSQL_DATABASE}
MYSQL_USER: ${MYSQL_USER}
MYSQL_PASSWORD: ${MYSQL_PASSWORD}
The trick: depends_on (check here) and condition (check the example).