Cannot work CentOS, but Ubuntu work fine

[JmyW]

I have tried both CentOS 8 and Ubuntu 20.10.
It's quite simple, just able to make it work perfectly in Ubuntu 20.10.
But same docker-compose.yml cannot work in CentOS 8. I have tried many time re-installation of CentOS. Unfortunately just failed.
The docker compose is well completed. But when I visit 127.0.0.1:8000, it just feedback "502 Bad Gateway". Access 127.0.0.1:8080 for PhpMyAdmin, it appear the query of host/account/password. When I input the host/account/password, it gives message " mysqli::real_connect(): (HY000/2002): No route to host".

I tested the Ubuntu and CentOS back and forth twice on "same" machine. The Ubuntu can work everytime. The CentOS failed everytime.

[JmyW]

Anyone know how to resolve it? thanks in advance.

[bclincy]

Looks like CentOS Docker local networking working. You can add your own private network and use IP addresses.
You can use the IP vs the [https://docs.docker.com/config/containers/container-networking/](docker DNS)
In your PDO string you can replace it with the IP

networks:
  LEMP:
    ipam:
      driver: default
      config:
        - subnet: 172.21.0.0/16
  services:
    web:
        image: nginx:alpine
        volumes:
            - "./etc/nginx/default.conf:/etc/nginx/conf.d/default.conf"
            - "./etc/nginx/nginx_custom.conf:/etc/nginx/conf.d/nginx_custom.conf"
            - "./etc/ssl:/etc/ssl"
            - "./web:/var/www/html"
            - "./etc/nginx/default.template.conf:/etc/nginx/conf.d/default.template"
         networks:
             LEMP:
                 ipv4_address: 172.21.0.11
        env_file:
            - ".env"
        ports:
            - "8000:80"
            - "3000:443"
        environment:
            - NGINX_HOST=${NGINX_HOST}
        command: /bin/sh -c "envsubst '$$NGINX_HOST' < /etc/nginx/conf.d/default.template > /etc/nginx/conf.d/default.conf && nginx -g 'daemon off;'"
        restart: always
        depends_on:
            - php
            - mysqldb
    php:
        image: nanoninja/php-fpm:${PHP_VERSION}
        restart: always
        environment:
            - NGINX_HOST=${NGINX_HOST}
            - MYSQL_DATABASE=${MYSQL_DATABASE}
            - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD}
            - MYSQL_USER=${MYSQL_USER}
            - MYSQL_PASSWORD=${MYSQL_PASSWORD}
            - MYSQL_HOST=${MYSQL_HOST}
        volumes:
            - "./etc/php/php.ini:/usr/local/etc/php/conf.d/php.ini"
            - "./web:/var/www/html"
         networks:
             LEMP:
                 ipv4_address: 172.21.0.9
    composer:
        image: "composer"
        volumes:
            - "./web/app:/app"
        command: ["composer", "install"]
    myadmin:
        image: phpmyadmin/phpmyadmin
        container_name: phpmyadmin
        ports:
            - "8080:80"
        environment:
            - PMA_ARBITRARY=1
            - PMA_HOST=${MYSQL_HOST}
        restart: always
        depends_on:
            - mysqldb
         networks:
             LEMP:
                 ipv4_address: 172.21.0.10
    mysqldb:
        image: mysql:${MYSQL_VERSION}
        container_name: ${MYSQL_HOST}
        restart: always
        env_file:
            - ".env"
        environment:
            - MYSQL_DATABASE=${MYSQL_DATABASE}
            - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD}
            - MYSQL_USER=${MYSQL_USER}
            - MYSQL_PASSWORD=${MYSQL_PASSWORD}
        ports:
            - "8989:3306"
        volumes:
            - "./data/db/mysql:/var/lib/mysql"
            - ./data/sql-scripts/:/docker-entrypoint-initdb.d/ # sql file for loading initial data
         networks:
             LEMP:
                 ipv4_address: 172.21.0.7

[JmyW]

@bclincy Thanks for guidance. My server was a new creation, so I could decide which one I can install with less issue. Since the problem I posted before, therefore I decided to adopt the Debian Linux. And it works fine like Ubuntu. And I'm sorry I won't be back CentOS for further try. I leave this to comment by others if someone check it.