データベースの設定

mysite/mysite/settings.py を追加/編集します。

mysite/mysite/settings.py

from pathlib import Path
import os  # 追加

mysite/mysite/settings.py

# SECRET_KEY = 'django-insecure-397uw9vefl&p92vxz72l+7zxk8nkd(33vlwcg1y_dihdjz0hfo'
SECRET_KEY = os.environ.get("SECRET_KEY")  # 変更

# SECURITY WARNING: don't run with debug turned on in production!
# DEBUG = True
DEBUG = os.environ.get("DEBUG") == "True"  # 変更

# ALLOWED_HOSTS = []
ALLOWED_HOSTS = ["localhost", "127.0.0.1", "[::1]"]  # 変更

mysite/mysite/settings.py

DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.mysql",
        # コンテナ内の環境変数をDATABASESのパラメータに反映
        "NAME": os.environ.get("MYSQL_DATABASE"),
        "USER": os.environ.get("MYSQL_USER"),
        "PASSWORD": os.environ.get("MYSQL_PASSWORD"),
        "HOST": "db",
        "PORT": 3306,
        "OPTIONS": {
            "init_command": "SET sql_mode='STRICT_TRANS_TABLES'",
        },
    }
}

docker-compose.dev.yml を編集し、データベース起動後にアプリケーションが起動するようにします。

docker-compose.dev.yml

version: '3.9'
services:
  app:
    container_name: django
    build:
      dockerfile: ./docker/app/Dockerfile
    ports:
      - 8000:8000
    env_file: ./docker/.env.dev
    command: poetry run python manage.py runserver 0.0.0.0:8000
    depends_on:
      db:
        condition: service_healthy
  db:
    container_name: mysql
    image: mysql:8
    volumes:
      - ./docker/db/data:/var/lib/mysql
      - ./docker/db/conf.d:/etc/mysql/conf.d
    env_file: ./docker/.env.dev
    ports:
      - "3306:3306"
    privileged: true
    healthcheck:
      test: mysqladmin ping -h 127.0.0.1 -u$$MYSQL_USER -p$$MYSQL_PASSWORD
      interval: 10s
      timeout: 10s
      retries: 3
      start_period: 30s

コンテナを起動します。

docker compose -f docker-compose.dev.yml up -d

コンテナが起動していることを確認します。

docker compose -f docker-compose.dev.yml ps

NAME                IMAGE                      COMMAND                  SERVICE             CREATED             STATUS                   PORTS
django              django-docker-sample-app   "poetry run python m…"   app                 6 minutes ago       Up 6 minutes             0.0.0.0:8000->8000/tcp, :::8000->8000/tcp
mysql               mysql:8                    "docker-entrypoint.s…"   db                  6 minutes ago       Up 6 minutes (healthy)   0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 33060/tcp

ログにエラーがないことを確認します。

docker compose -f docker-compose.dev.yml logs

マイグレーションファイルを生成します。

docker compose -f docker-compose.dev.yml exec app poetry run python manage.py makemigrations

Migrations for 'polls':
polls/migrations/0001_initial.py
   - Create model Question
   - Create model Choice

マイグレーションを実行します。

docker compose -f docker-compose.dev.yml exec app poetry run python manage.py migrate

Operations to perform:
Apply all migrations: admin, auth, contenttypes, polls, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying admin.0003_logentry_add_action_flag_choices... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying auth.0010_alter_group_name_max_length... OK
Applying auth.0011_update_proxy_permissions... OK
Applying auth.0012_alter_user_first_name_max_length... OK
Applying polls.0001_initial... OK
Applying sessions.0001_initial... OK

コンテナを終了します。

docker compose -f docker-compose.dev.yml down