Problem with wordpress and mysql database : cannot communicate

General
1

Hi Guys.

i got a raspberry pi 3 running docker and i would like to create a private wordpress website abailable only on my private newtwork.
What i want to do is set up a container for wordpress and another one for the database (mysql).
i also want to create some volumes to save all the configurations in case i would need to delete the containers.

So i started to create a docker-compose file and i seems my too containers cannot communicate to each other.
Here is the file :

version: '3.7'

services:
 wordpress:
  depends_on:
   - db
  links:
   - db
  image: wordpress
  container_name: wordpress_web
  restart: always
  ports:
   - 8080:80
  environment:
   WORDPRESS_DB_HOST: db:3306
   WORDPRESS_DB_USER: WP-User
   WORDPRESS_DB_PASSWORD: WP-password
   WORDPRESS_DB_NAME: databasename
  networks:
   - wordpress-network
  volumes:
   - 'wordpress_data:/var/www/html'
 db:
  image: hypriot/rpi-mysql
  container_name: wordpress_database
  restart: always
  environment:
   MYSQL_DATABASE: databasename
   MYSQL_USER: WP-User
   MYSQL_PASSWORD: WP-password
   MYSQL_ROOT_PASSWORD: root-password
  networks:
   - wordpress-network
  volumes:
      - 'db_data:/var/lib/mysql'
volumes:
 wordpress_data:
  driver: local
  driver_opts:
   type: nfs
   o: addr=192.168.**.**,rw
   device: ":/*****/*****/wordpress/var/www/html"
 db_data:
  driver: local
  driver_opts:
   type: nfs
   o: addr=192.168.**.**,rw
   device: ":/*****/*****/wordpress/var/lib/mysql"
networks:
 wordpress-network:
  driver: bridge
  ipam:
   config:
    - subnet: IP / SUBNET MASK

When i try this i got an error telling me that’s it’s impossible to contact the database.
When i remove wordpress “environment” part, i can see the web site but it still cannot communicate with the database container.

Can you help me to sole this problem ?

I’m sorry if this is a stupid question but i’m new with docker and i didn’t find anything online about this.

Thx a lot for your help.

2

hi.
Do you guys have an idea about this ?
thx