Docker Mysql SQLSTATE[HY000] [2002] Connection refused.

Oi !

Estou criando meu ambiente de desenvolvimento em docker. Mas estou com alguns problemas:

Eu consigo me conectar no container mysql por um SGBD, porém eu não consigo me conectar através do php-fpm, gera um erro :

SQLSTATE[HY000] [2002] Connection refused. 

Segue minha configuração:

docker-compose.yml

version: "3"
services:
  nginx:
    image: "nginx:1.17.2"
    container_name: "nginx-php-general"
    volumes: 
      - "./nginx/www:/usr/share/nginx/html/"
      - "./nginx/config/1-web.conf:/etc/nginx/conf.d/1-web.conf"
      - "./nginx/logs/web.access.log:/var/log/nginx/web.access.log"
      - "./nginx/logs/web.error.log:/var/log/nginx/web.error.log"
    ports:
      - "80:80"
    networks:
      - "networks-php-general"
    depends_on: 
      - "php-fpm"
  php-fpm:
    build: 
      "./php"
    container_name: "php-fpm-php-general"
    # Since PHP is running in its own environment (container) it doesn't have access to the code.
    # In order to fix this, we need to mount the code folder in the PHP container too. 
    # This way Nginx will be able to serve any static files, and PHP will be able to find the files 
    # it has to interpret. One final change to the docker-compose.yml
    volumes: 
      - "./nginx/www:/usr/share/nginx/html/"
    networks:
      - "networks-php-general"
  mysql: 
    image: "mysql:8.0.17"
    container_name: "mysql-php-general"
    environment:
      MYSQL_ROOT_PASSWORD: ""
      MYSQL_ALLOW_EMPTY_PASSWORD: "yes"
      MYSQL_DATABASE: "default-base"
      MYSQL_USER: "guest"
      MYSQL_PASSWORD: ""
    ports:
      - "3306:3306"
    networks:
      - "networks-php-general"

networks:
  networks-php-general:
    driver: "bridge"

conexao.php

<?php
try {
    $dbh = new PDO('mysql:host=mysql-php-general;port=3306;dbname=default-base', 'guest', '');
} catch (PDOException $e) {
    print "Error!: " . $e->getMessage() . "<br/>";
    die();
}

Fora a conexão entre container mysql e php-fpm as demais partes estão funcionando certinho.

Quem puder me ajudar ficar muito grato, estou quebrando a cabeça para saber o que está acontecendo.

Vlw!