AWS MediaConnect CloudFormation中srt-listener协议正确取值咨询

问题描述 #

我编写了如下AWS CloudFormation模板：

Resources:
  MediaConnectFlowSource:
    Type: 'AWS::MediaConnect::FlowSource'
    Properties:
      Description: SRTSource
      Name: SRTSource
      WhitelistCidr: 0.0.0.0/0
      Protocol: srt-listener
  MediaConnectFlow:
    Type: 'AWS::MediaConnect::Flow'
    Properties:
      Name: testStream
      Source: !Ref MediaConnectFlowSource
  MediaConnectFlowOutput:
    Type: 'AWS::MediaConnect::FlowOutput'
    Properties:
      CidrAllowList: 0.0.0.0/0
      FlowArn: !Ref MediaConnectFlow
      Name: SRTOutput
      Protocol: srt-listener

尝试创建资源时触发以下验证错误：

Properties validation failed for resource MediaConnectFlowSource with message: #/Protocol: #: only 1 subschema matches out of 2 #/Protocol: failed validation constraint for keyword [enum]

查阅CloudFormation文档发现，MediaConnect Flow Source的允许协议枚举值未列出srt-listener，但SDK和MediaConnect控制台中存在该枚举值。尝试了SRT-listener、srt listener等多种写法均报错，请问srt-listener协议的正确取值是什么？

解决方案 #

MediaConnect FlowSource的srt-listener协议在CloudFormation中的正确枚举值是**SRT_LISTENER**（大写字母+下划线分隔）。

AWS CloudFormation对资源属性的枚举值要求通常采用大写下划线格式，和控制台/SDK显示的短横线小写格式存在差异，这是导致验证报错的核心原因。

修改后的关键字段示例：

# MediaConnectFlowSource部分
Protocol: SRT_LISTENER

# MediaConnectFlowOutput部分
Protocol: SRT_LISTENER

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