Why does cloudformation give "Invalid method response 200" error, but manual deployment work? (AWS API Gateway Websocket) - aws-cloudformation

Question

I am getting this error when I deploy a simple websocket mock route.
Execution failed due to configuration error: Output mapping refers to an invalid method response: 200
First of all, I'm a little confused about what method response means, as in Websocket API, the terminology used is Route Response and Integration Response. I'm guessing this is referring to the Route Response.
The resources I have are:
Websocket API
Stage
Deployment
$connect route
$connect integration with mock (default maps to {"statusCode": 200})
$connect integration response (just passes the integration through)
$connect route response
The funny part is: to fix this, all I have to do is go to the console and click deploy API. I don't have to change any configuration. But that is not a good solution for me, as I want to run this on a CI/CD pipeline.
I'm guessing the problem is with the Route Response, as that is not configurable from the console. So something must be going on behind the scenes during console deployment, which I am missing during cloudformation deployment. Any ideas how to solve this?
Here's my Cloudformation Template.
Resources:
testWsApiBackendWsApi40DF2EE8:
Type: AWS::ApiGatewayV2::Api
Properties:
Name: testWsApi
ProtocolType: WEBSOCKET
RouteSelectionExpression: $request.body.action
testWsApiApiDeployment423ACBB9:
Type: AWS::ApiGatewayV2::Deployment
Properties:
ApiId:
Fn::GetAtt:
- testWsApiBackendWsApi40DF2EE8
- ApiId
DependsOn:
- MockWithAuthAwsStackwsMockRoute04DB7577
testWsApiApiStageF40CAAE0:
Type: AWS::ApiGatewayV2::Stage
Properties:
ApiId:
Fn::GetAtt:
- testWsApiBackendWsApi40DF2EE8
- ApiId
StageName: production
DeploymentId:
Fn::GetAtt:
- testWsApiApiDeployment423ACBB9
- DeploymentId
MockWithAuthAwsStackwsMockRoute04DB7577:
Type: AWS::ApiGatewayV2::Route
Properties:
ApiId:
Fn::GetAtt:
- testWsApiBackendWsApi40DF2EE8
- ApiId
RouteKey: $connect
Target:
Fn::Join:
- ""
- - integrations/
- Ref: MockWithAuthAwsStackwsMockIntegration36E7A460
MockWithAuthAwsStackwsMockIntegration36E7A460:
Type: AWS::ApiGatewayV2::Integration
Properties:
ApiId:
Fn::GetAtt:
- testWsApiBackendWsApi40DF2EE8
- ApiId
IntegrationType: MOCK
PassthroughBehavior: WHEN_NO_TEMPLATES
RequestTemplates:
$default: '{"statusCode":200}'
TemplateSelectionExpression: \$default
MockWithAuthAwsStackwsMockRouteResponseAEE0B8ED:
Type: AWS::ApiGatewayV2::RouteResponse
Properties:
ApiId:
Fn::GetAtt:
- testWsApiBackendWsApi40DF2EE8
- ApiId
RouteId:
Ref: MockWithAuthAwsStackwsMockRoute04DB7577
RouteResponseKey: $default
MockWithAuthAwsStackwsMockIntegrationResponse85928773:
Type: AWS::ApiGatewayV2::IntegrationResponse
Properties:
ApiId:
Fn::GetAtt:
- testWsApiBackendWsApi40DF2EE8
- ApiId
IntegrationId:
Ref: MockWithAuthAwsStackwsMockIntegration36E7A460
IntegrationResponseKey: $default
TemplateSelectionExpression: \$default
P.S I am actually using AWS CDK. The above template is the result of cdk synth. Let me know if you want to see the CDK code.

Answer 1

The reason why manual deployment using console works, while using cloudformation causes errors occasionally, is due to the order in which these resources are created. In the console, this is the order followed:
Routes, Integrations and Responses are created
They are associated with a stage
They are deployed to the specified stage
When using cloudformation, the order of creation of resources gets mixed up, resulting in them not being wired up properly. It seems that you have wired up the deployment to depend on the route being created first. You also need to make sure that the stage is created before the deployment. For this you could add an explicit DependsOn attribute, or an implicit reference to the stage within the deployment; perhaps in the stageName attribute as !Ref StageResource.
Or you could save the trouble and just add an autoDeploy: true to your stage, which will take care of the linking and order on its own.