django アプリケーション毎に データベースを分ける

settings.py

INSTALLED_APPS = [
    ...
    'app1.apps.App1Config',
    'app2.apps.App2Config',
]


DATABASES = {
    'default': {
        ....
    },
    'db2': {
        ....
    },
}
DATABASE_ROUTERS = ['config.db_router.DbRouter']

modelに追加

※重要
ここのapp_labelをmodel_routerで識別する

class User(models.Model):
	class Meta:
		app_label = 'apiv2'

ファイル追加

config/db_router.py

class DbRouter:
	def db_for_read(self, model, **hints):

		if model._meta.app_label == 'apiv1':
			return 'default'
		if model._meta.app_label == 'apiv2':
			return 'db2'
		return None

	def db_for_write(self, model, **hints):
		if model._meta.app_label == 'apiv1':
			return 'default'
		if model._meta.app_label == 'apiv2':
			return 'db2'
		return None

	def allow_relation(self, obj1, obj2, **hints):
		return True

	def allow_migrate(self, db, app_label, model=None, **hints):
		if app_label == 'auth' or app_label == 'contenttypes' or app_label == 'sessions' or app_label == 'admin':
			return db == 'default'
		if app_label == 'apiv1':
			return db == 'default'
		if app_label == 'apiv2':
			return db == 'db2'
		return None

migrate

CORS_ORIGIN_ALLOW_ALL
CORS_ORIGIN_WHITELIST
が邪魔するので一旦コメントアウト

docker-compose run back ./manage.py makemigrations
docker-compose run back ./manage.py migrate --database=db2