Terraform：如何在选项组的选项中添加多个option_settings

问题重现 #

尝试创建RDS选项组时，为单个选项添加多个配置值，最初使用了列表形式的配置：

option {
    option_name = "VALID_OPTION_NAME"
    option_settings = [
      {
        name  = "foobar1"
        value = "foobar1"
      },
      {
        name  = "foobar2"
        value = "foobar2"
      },
      {
        name  = "foobar3"
        value = "foobar3"
      },
      {
        name  = "foobar4"
        value = "foobar4"
      },
      {
        name  = "foobar5"
        value = "foobar5"
      }
    ]
  }

执行terraform validate后触发错误：

on rds.tf line 112, in resource "aws_db_option_group" "rds-option-group":
 112:     option_settings = [

An argument named "option_settings" is not expected here. Did you mean to
define a block of type "option_settings"?

注：AWS控制台原生支持单个选项添加多配置，因此Terraform必然有对应实现，但官方文档无相关示例，且未使用第三方模块的情况下，现有讨论线程无法提供有效帮助。

正确配置方案 #

option_settings是Terraform AWS Provider中aws_db_option_group资源的嵌套块，而非普通参数，需通过重复定义块的方式添加多组配置：

option {
    option_name = "xx"
    option_settings {
      name  = "xx"
      value = "xx"
    }
    option_settings {
      name  = "xx"
      value = "xx"
    }
    option_settings {
      name  = "xx"
      value = "xx"
    }
    option_settings {
      name  = "xx"
      value = "xx"
    }
  }

内容的提问来源于stack exchange，提问作者numbersgoup