Docker Compose - Connection to Phpmyadmin and MySQL not working

Question

I need an easy way to create an environment with PHP, NGINX, MySQL, and phpmyadmin using Docker-compose.

I have successfully created a PHP environment using NGINX.

Now I want to add a database with MySQL and phpmyadmin. These two components don't seem to work. For example, I cannot access phpmyadmin by specifying port "8081". I access the local server using the local IP address and the port at the end of the address.

When I want to call phpmyadmin, the browser window tells me "Unable to connect to server".

This is the docker-compose.yml file:

version: "3.9"

services:
    web:
        image: nginx:latest
        ports:
            - "8080:80"
        volumes:
            - ./src:/var/www/html
            - ./default.conf:/etc/nginx/conf.d/default.conf
        links:
            -php-fpm
    php-fpm:
        image: php:8-fpm
        volumes:
            - ./src:/var/www/html
    mysql:
        image:mysql
        container_name: mysql
        environment:
              MYSQL_ROOT_PASSWORD: '<mypassword>'
              MYSQL_DATABASE:baton
              MYSQL_USER:baton
              MYSQL_PASSWORD: '<mypassword>'
        ports:
              - "3306:3306"
        volumes:
              - ./database/mysql:/var/lib/mysql
    phpmyadmin:
        image: phpmyadmin/phpmyadmin
        container_name: pma
        links:
              - mysql
        environment:
              PMA_HOST: mysql
              PMA_PORT: 3306
              PMA_ARBITRARY: 1
        restart: always
        ports:
              - 8081:80

Hope everyone can help!

Answer 1

Now I found that I made a mistake when connecting to the database through phpmyadmin. I got the second database and it's already running on port 3306. I have now switched to the existing database and the connection now works!