How to establish database connection from wordpress docker - mysql

Question

I try running a docker compose wordpress by using this guide: https://docs.docker.com/compose/wordpress/
This is the yaml file as described in the guide:
version: '3.3'
services:
db:
image: mysql:5.7
volumes:
- db_data:/var/lib/mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: wordpress
MYSQL_DATABASE: wordpress
MYSQL_USER: wordpress
MYSQL_PASSWORD: wordpress
wordpress:
depends_on:
- db
image: wordpress:latest
ports:
- "8000:80"
restart: always
environment:
WORDPRESS_DB_HOST: db:3306
WORDPRESS_DB_USER: wordpress
WORDPRESS_DB_PASSWORD: wordpress
WORDPRESS_DB_NAME: wordpress
WORDPRESS_DEBUG: "true"
volumes:
db_data: {}
After I run my
"docker-compose up -d"
command, I go to "http://localhost:8000/" in my browser and get the white page with "Error establishing a database connection". According to the guide, wordpress should show me the 5 minute Installation already at this point. When I run the container with wordpress debug true, this error message is shown then:
Warning: mysqli_real_connect(): (HY000/2002): Connection refused in /var/www/html/wp-includes/wp-db.php on line 1612
Connection refused
I now use
docker exec it container_id /bin/bash
and type "mysql -p". Now I use the MYSQL_ROOT_PASSWORD from the docker compose file but I get access denied ("Access denied for user 'root'#'localhost' (using password: YES)")
I am not sure what I did earlier, but at some point it worked and I listed the databases and the mysql.users and the db and user were there.
So I dont even know, what the problem here is...
And why can I not access as root anymore? Does anyone know what to do?
EDIT: changed port back to 3306, I tried 3308 just to see if that may be a port issue

Answer 1

I found another post and they used this yaml. Still not sure why this works, but it does.
version: '3.3'
services:
db:
image: mysql:5.7
volumes:
- db_data:/var/lib/mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: wordpress
MYSQL_DATABASE: wordpress
MYSQL_USER: wordpress
MYSQL_PASSWORD: wordpress
wordpress:
depends_on:
- db
image: wordpress:latest
ports:
- 8000:80
restart: always
environment:
WORDPRESS_DB_HOST: db:3306
WORDPRESS_DB_USER: wordpress
WORDPRESS_DB_PASSWORD: wordpress
volumes:
db_data: {}

Answer 2

Check the logs of a service. To check the services, do:
$ docker-compose logs
...
db_1 | 2022-10-21 2:08:08 0 [Note] InnoDB: Buffer pool(s) load completed at 221021 2:08:08
db_1 | 2022-10-21 2:08:08 0 [Note] mysqld: ready for connections.
db_1 | Version: '10.6.4-MariaDB-1:10.6.4+maria~focal' socket: '/run/mysqld/mysqld.sock' port: 3306 mariadb.org binary distribution
For example, If you have a mariadb service named db and it doesn't print that way, you might have to wait for it to print.