API Gateway: "Unable to determine service/operation name to be authorized"

[corymatheson]

When attempting to invoke a lambda via API-Gateway, I receive the following 502 error.

Endpoint response body before transformations: <AccessDeniedException> <Message>Unable to determine service/operation name to be authorized</Message> </AccessDeniedException>

This appears to only happen on endpoints that utilize Authorizers.
Current versions:
AWSTemplateFormatVersion: '2010-09-09' Transform: AWS::Serverless-2016-10-31

I followed the steps discussed by @lusentis and @jfuss here: [https://github.com//issues/59] but I didn't see any change as a result.
I also (unsuccessfully) attempted to manually add/remove permissions in the policy to track down the exact syntax that would work. As long an apigateway invoke permission exists, I get the 502, if no permissions exist I receive a 500 as expected.
The HTTP method doesn't seem to affect the result.

I would be happy to include an example of my setup if that would help.

[corymatheson]

Looks like the issue was with out API Swagger yml file. As indicated in the docs, x-amazon-apigateway-integration MUST be a POST for lamba integrations.

Thanks for pointing in the right direction. I was using the C# AWS SDK, making a 'PutIntegrationRequest'. I falsely set the 'IntegrationHttpMethod' to the same http method that I wanted to create on a resource, e.g. GET and I got the above error. Changing this to always be 'POST' did the trick :-)

[aruizeac]

Looks like the issue was with out API Swagger yml file. As indicated in the docs, x-amazon-apigateway-integration MUST be a POST for lamba integrations.

I can confirm this. I had a similar problem but using Terraform.

Thanks a lot!

[rafilkmp3]

yes you must use post with integration thanks @NurSpass

ex:

resource "aws_api_gateway_integration" "this" {
  rest_api_id             = aws_api_gateway_rest_api.api-gateway.id
  resource_id             = aws_api_gateway_resource.this.id
  http_method             = aws_api_gateway_method.this.http_method
  integration_http_method = "POST"
  type                    = "AWS_PROXY"
  uri                     = module.lambda.invoke_arn
}

[m1chae1bx]

Can anyone put a link on the docs stating that a POST method must be used instead of GET? I am quite confused. Thank you.

[davidhonig]

In Lambda proxy integration, the required setup is simple. Set the integration's HTTP method to POST, the integration endpoint URI to the ARN of the Lambda function invocation action of a specific Lambda function, and grant API Gateway permission to call the Lambda function on your behalf.
https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-integrations.html

[m1chae1bx]

Thanks @davidhonig!

[jzeelenberg]

OMG I am embarrassed to admit how much time I lost to this issue. Thank you so much @corymatheson and @davidhonig .

[gabrielolvv]

I tried changing my API Gateway request method to 'POST,' but I still encounter the error. Is there anything else that could help me? @jzeelenberg

[TomHartogs-Neople]

We have our integration_http_method set to POST but after every infra deploy we need to redeploy the API gateway stage @gabrielolvv. Currently trying to figure out why this is needed, but this might be of help for you.