Enable CORS for API Gateway in Cloudformation template

Question

I'm creating AWS Cloudformation template for my environment and I can't find a way to enable CORS for API Gateway method.

I can configure it using AWS console (here is the official doc), but how can I do it in the Cloudformation template?

Answer 1

After some trial and error, I found that the following CloudFormation template snippet will produce an equivalent OPTIONS method when compared to the CORS console wizard:

OptionsMethod:
  Type: AWS::ApiGateway::Method
  Properties:
    AuthorizationType: NONE
    RestApiId:
      Ref: MyApi
    ResourceId:
      Ref: MyResourceOnWhichToEnableCORS
    HttpMethod: OPTIONS
    Integration:
      IntegrationResponses:
      - StatusCode: 200
        ResponseParameters:
          method.response.header.Access-Control-Allow-Headers: "'Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token'"
          method.response.header.Access-Control-Allow-Methods: "'POST,OPTIONS'"
          method.response.header.Access-Control-Allow-Origin: "'*'"
        ResponseTemplates:
          application/json: ''
      PassthroughBehavior: WHEN_NO_MATCH
      RequestTemplates:
        application/json: '{"statusCode": 200}'
      Type: MOCK
    MethodResponses:
    - StatusCode: 200
      ResponseModels:
        application/json: 'Empty'
      ResponseParameters:
          method.response.header.Access-Control-Allow-Headers: false
          method.response.header.Access-Control-Allow-Methods: false
          method.response.header.Access-Control-Allow-Origin: false

*Note 1: This is an example of taking the defaults for a POST. Obviously, you'll need to update Access-Control-Allow-Methods to include the values you need.

*Note 2: Kudos to the AWS CloudFormation team for recently introducing YAML support. If you need to convert to/from YAML/JSON, I have found this site handy: http://www.json2yaml.com/