'mysql' => [
                'read' => [
                    'host' => $host,
                    'username' => $username,
                    'password' => env('DB_PASSWORD_R', ''),
                ],
                'write' => [
                    'host' => explode(',', env('DB_HOST_W', '')),
                    'username' => env('DB_USERNAME_W', ''),
                    'password' => env('DB_PASSWORD_W', ''),
                ],
                'driver' => 'mysql',
                'port' => env('DB_PORT', '3306'),
                'database' => env('DB_DATABASE', ''),
                'charset' => 'utf8mb4',
                'collation' => 'utf8mb4_unicode_ci',
                'prefix' => '',
                'prefix_indexes' => false,
                'strict' => true,
                'engine' => null,
                // MySQLはUTC、LaravelはJSTの場合
                'timezone' => '+09:00',
                'sticky' => false,
            ],
        ],