概要

フォルダ構成

.
├─docker-compose.yml
└─mysql
   └─conf.d
      └─mysql.cnf

ファイル

docker-compose.yml

version: '3.8'
services:
  db:
    image: mysql:8.0
    ports:
      - '3306:3306'
    volumes:
      - ./mysql/conf.d:/etc/mysql/conf.d
      - mysql:/var/lib/mysql
    restart: always
    environment:
      MYSQL_ALLOW_EMPTY_PASSWORD: 1
      TZ: "Asia/Tokyo"
volumes:
  mysql:

mysql/conf.d/mysql.cnf

[mysqld]
default_authentication_plugin = mysql_native_password
skip-host-cache
skip-name-resolve

character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
init-connect = SET NAMES utf8mb4
skip-character-set-client-handshake

[client]
default-character-set = utf8mb4

[mysqldump]
default-character-set = utf8mb4

[mysql]
default-character-set = utf8mb4

コマンド

コンテナ起動

docker-compose up -d

mysql接続

docker-compose run db mysql -h db -u root

結果

# mysql -h db -u root
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.26 MySQL Community Server - GPL

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

以上

railsなどから接続する際にはdatabase.ymlにてhost: dbとしてやる