Docker / phpmyadmin: Unable to connecto

Question

I have the following docker-compose file.

version: "3.7"
services:
  main:
    container_name: buspack_main
    build:
      context: .
      target: development
    volumes:
      - .:/usr/src/app
      - /usr/src/app/node_modules
    ports:
      - ${API_PORT}:${API_PORT}
    command: bash -c "npm install --save && npm run start:dev"
    env_file:
      - .env
    networks:
      - webnet
    depends_on:
      - db
    links:
      - db
    restart: always

  db:
    container_name: buspack_db
    image: mysql:5.7.33
    networks:
      - webnet
    environment:
      MYSQL_ROOT_PASSWORD: 123456
      MYSQL_DATABASE: "backendnest"
    ports:
      - 23306:3306
    restart: always
    volumes:
      - ./db:/var/lib/mysql:rw

  phpmyadmin:
    container_name: buspack_phpmyadmin
    image: phpmyadmin/phpmyadmin
    depends_on:
      - db
    restart: always
    ports:
      - '8030:80'
    environment:
      PMA_HOST: buspack_db
      MYSQL_ROOT_PASSWORD: 123456
networks:
  webnet:
volumes:
  db: {}

My problem Is that when I try to login with phpmyadmin I get the following error:

mysqli::real_connect(): php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution

And also

mysqli::real_connect(): (HY000/2002): php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution

Is there something I'm missing?

Answer 1

    networks:
      - webnet

add webnet network to phpmyadmin service

Answer 2

There are more options to solve the connection.

1. Add phpmyadmin container to webnet network as Def Soudani suggests. The YML example provided overrides the default network. Since the phpMyAdmin is lacking the network config, it won't be on the webnet docker network by default.
2. Remove all networks related config from the YML. Since compose already creates a default network (docs) for the containers within one YML file.
3. Use the PMA_ARBITRARY=1 (docs )which allows you to enter a database server hostname on login form.

Example of my YML setup with custom bridge networking:

version: '3.8'

services:
  mysql:
    image: mysql:5.7
    container_name: myapp-mysql-db
    restart: unless-stopped
    ports:
      - "3306:3306"
    environment:
      MYSQL_DATABASE: ${DB_DATABASE}
      MYSQL_ROOT_PASSWORD: ${DB_PASSWORD}
      MYSQL_PASSWORD: ${DB_PASSWORD}
      MYSQL_USER: ${DB_USERNAME}
    volumes:
      - ./database/dbdata:/var/lib/mysql
    networks:
      - myapp-network

  phpmyadmin:
    image: phpmyadmin:latest
    container_name: phpmyadmin
    ports:
      # 8080 is the host port and 80 is the docker port
      - 8080:80
    environment:
      PMA_HOST: mysql
      UPLOAD_LIMIT: 20M
      MYSQL_USERNAME: ${DB_USERNAME}
      MYSQL_ROOT_PASSWORD: ${DB_PASSWORD}
    restart: unless-stopped
    networks:
      # define your network where all containers are connected to each other
      - myapp-network

networks:
  myapp-network:
    driver: bridge