CloudFormationのデプロイしてたらこんな感じのエラーが出ました。

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

使用していたCloudFormationテンプレートはこちらです。

AWSTemplateFormatVersion: 2010-09-09
Description: "API Gateway"
Parameters:
  FunctionName:
    Type: String
Resources:
  Api:
    Type: "AWS::ApiGateway::RestApi"
    Properties:
      Name: "api"
  ResourceAWS:
    Type: "AWS::ApiGateway::Resource"
    Properties:
      RestApiId: !Ref Api
      ParentId: !GetAtt Api.RootResourceId  
      PathPart: aws
  LambdaPermission:
    Type: "AWS::Lambda::Permission"
    Properties:
      FunctionName: !Sub "${FunctionName}"
      Action: "lambda:InvokeFunction"
      Principal: "apigateway.amazonaws.com"
  AWSResourceMethod:
    Type: "AWS::ApiGateway::Method"
    Properties:
      RestApiId: !Ref Api
      ResourceId: !Ref ResourceAWS
      AuthorizationType: NONE
      HttpMethod: GET
      Integration:
        Type: AWS
        IntegrationHttpMethod: "POST"
        Uri: !Sub "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/arn:aws:lambda:${AWS::Region}:${AWS::AccountId}:function:${FunctionName}/invocations"
    DependsOn: "LambdaPermission"

解決する方法

なんてことはないNoneをNONEにするだけ

AWSTemplateFormatVersion: 2010-09-09
Description: "API Gateway"
Parameters:
  FunctionName:
    Type: String
Resources:
  Api:
    Type: "AWS::ApiGateway::RestApi"
    Properties:
      Name: "api"
  ResourceAWS:
    Type: "AWS::ApiGateway::Resource"
    Properties:
      RestApiId: !Ref Api
      ParentId: !GetAtt Api.RootResourceId  
      PathPart: aws
  LambdaPermission:
    Type: "AWS::Lambda::Permission"
    Properties:
      FunctionName: !Sub "${FunctionName}"
      Action: "lambda:InvokeFunction"
      Principal: "apigateway.amazonaws.com"
  AWSResourceMethod:
    Type: "AWS::ApiGateway::Method"
    Properties:
      RestApiId: !Ref Api
      ResourceId: !Ref ResourceAWS
-      AuthorizationType: NONE
+      AuthorizationType: None
      HttpMethod: GET
      Integration:
        Type: AWS
        IntegrationHttpMethod: "POST"
        Uri: !Sub "arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/arn:aws:lambda:${AWS::Region}:${AWS::AccountId}:function:${FunctionName}/invocations"
    DependsOn: "LambdaPermission"

参考にしたサイトではNONEだったのでそれで動いていた時期があったのかもしれません。

感想

それにしてもエラーメッセージが不親切すぎる。NONEは受け入れられませんと言ってくれればいいのに