mysqldump + docker 错误：执行备份时主机错误1045

Question

尝试使用backup容器自动备份位于dbmr容器上的数据库db_prod

mysqldump -h dbmr -u backup -p --databases 'db_prod' | gzip > /opt/mysql/backup/test.sql.gz

但出现错误

mysqldump: Got error: 1045: "Access denied for user 'backup'@'172.29.0.2' (using password: YES)" when trying to connect

问题是主机172.29.0.2错误； 应该是backup

我创建了这个用户

CREATE USER 'backup'@'backup' IDENTIFIED BY 'password';
GRANT SELECT, SHOW VIEW, TRIGGER, LOCK TABLES ON `db_prod`.* TO 'backup'@'backup';
FLUSH PRIVILEGES;

用户无法从主机backup连接

我有这个docker compose

version: "3"
services:

  dbmr:
    container_name: dbmr
    restart: always
    env_file: .env
    environment:
      MYSQL_ROOT_PASSWORD: "${MYSQL_ROOT_PASSWORD}"
      MYSQL_DATABASE: "${MYSQL_DATABASE}"
    ports:
      - "3306:3306"
    networks:
      - db_net

  database-backup:
    container_name: backup
    env_file: .env
    restart: always
    networks:
      - db_net

networks:
  db_net: