Wordpress behind jwilder nginx-proxy - Connection to DB container not working

General
1

I’m using nginx-proxy from J. Wilder in front of multiple website containers. Now I would like to create a wordpress contain behind the nginx-proxy.

The following docker-compose file works in principle. The domain name is reachable and requests are forwarded to wordpress container. However, Wordpress outputs an page with the error “Error establishing a database connection” so somehow Wordpress can’t reach the database.

version: '3.1'

services:
  app:
    container_name: mypagename_blog
    image: wordpress
    depends_on:
      - db
    environment:
      - WORDPRESS_DB_HOST=db:3306
      - WORDPRESS_DB_USER=mysqluser
      - WORDPRESS_DB_PASSWORD=password
      - WORDPRESS_DB_NAME=wordpress_db
      - VIRTUAL_HOST=mypagename.com
      - LETSENCRYPT_HOST=mypagename.com.
      - LETSENCRYPT_EMAIL=contact@mypagename.com
    volumes:
      - app:/var/www/html
    restart: unless-stopped
    expose:
    - 80

  db:
    image: mysql:8.0
    restart: always
    environment:
      MYSQL_DATABASE: wordpress_db
      MYSQL_USER: mysqluser
      MYSQL_PASSWORD: password
      MYSQL_RANDOM_ROOT_PASSWORD: randompassword
    volumes:
      - db:/var/lib/mysql
    expose:
      - 3306
      - 33060

volumes:
  app:
  db:

networks:
  default:
    external:
      name: nginx-proxy

docker network inspect nginx-proxy show all containers are in the network.
I’ve manually verified that the login mysql credentials in the db container are correct.
The container log does not show any error.
At the moment I’m not sure if the value of the environment variable WORDPRESS_DB_HOST is correct, because the container name is later used in wp-config.php and probably cannot be resolved correctly.

What can I do to narrow down the problem?

2

Try to explicitly create a regular Docker network with a name instead of using “default”, and attach the containers.

Update: WORDPRESS_DB_HOST=db

5

Thanks for your help. It was my mistake