Phpmyadmin and mysql connection fails after docker-compose down and up again-CodePudding

This is my docker-compose.yml file to launch PMA and mysql:

version: '3.8'
services:
 
  mysql_db:
    image: mysql:8.0.28
    ports:
      - "64121:3306"
    environment:
      - MYSQL_ROOT_PASSWORD=rootsecretpassword
      - MYSQL_DATABASE=dbname
      - MYSQL_USER=db-username
      - MYSQL_PASSWORD=db-password
    volumes:
      - mysql_data:/var/lib/mysql

  phpmyadmin:
    image: phpmyadmin/phpmyadmin:5.1.2
    ports:
      - "64122:80"
    environment:
      - MAX_EXECUTION_TIME=600 
      - UPLOAD_LIMIT=800M
      - PMA_HOST=mysql_db
      - PMA_PORT=3306
      - PMA_ARBITRARY=1
    depends_on:
      - mysql_db


volumes:
  mysql_data:

docker-compose up --build

Then, I can reach localhost:64122 to see PMA(phpmyadmin) and I can login using credentials and everything works fine, But after running docker-compose down and docker-compose up --build I can't login to PMA and it says:

 Cannot log in to the MySQL server
 mysqli::real_connect(): (HY000/1130): Host 'SOME IP ADRESS' is not allowed to connect to this MySQL server

So, what happens during down and up in docker that makes this error?

CodePudding user response：

Database user can connect only from localhost by default

SELECT host FROM mysql.user WHERE user = "db-username";

Update user table:

GRANT ALL ON dbname.* to 'db-username'@'%' IDENTIFIED BY 'db-password';
FLUSH PRIVILEGES;
SELECT host FROM mysql.user WHERE user = "db-username";