Enforcing usage plans when authenticating with JWT tokens using lambda authorizers

Question

In my API Gateway I authenticate the users with an authorizer lambda which validates Cognito JWT tokens. Despite having a customized flow which is not relying on API Keys, I want to enable usage plan enforcement by the API Gateway. How do I do that? Nothing I did so far had worked.

What have I tried so far?

I am generating a policy like this:

{
  "principalId": "testuser",
  "policyDocument": {
    "Version": "2012-10-17",
    "Statement": [
      {
        "Action": "execute-api:Invoke",
        "Effect": "Allow",
        "Resource": [
          "arn:aws:execute-api:eu-central-1:<accountnr>:<sth>/test/GET/*"
        ]
      }
    ]
  },
  "context": {
    "attribute1": "value1",
    "attribute2": "value2"
  },
  "usageIdentifierKey": "<api key>"
}

I have API key source set to Authorizer.

According to documentation I need to specify the attribute usageIdentifierKey if I want to use a usage plan assigned to the specified API key.

It does not work no matter if:

1. The attribute usageIdentifierKey is not present.
2. The attribute usageIdentifierKey value is set to the API key id/value/name/...

Answer 1

Stupid me. I forgot to deploy the usage plan into the stage. After the deployment everything works. I will leave it here for future generations.