Test case for replicating problems when attempting to run a Micronaut Lambda under an AWS ALB

See https://github.com/micronaut-projects/micronaut-core/issues/9160

Prerequisites

• Java 17
• AWS CLI
• CDK CLI

Setup:

Set your AWS credentials, typically either via environment variables or in ~/.aws/credentials

Modify infra/cdk.json to add your existing VPN to one of the environments (e.g. dev01-stack01)

Deploy

cd infra
cdk deploy -c config=dev01-stack01

Verification

External

If the deployment worked then one of the last lines should include a URL of your deployed Lambda. E.g: fubar-dev01-stack01-us-west-2.dns = fubar-dev01-stack01-alb-123456789.us-west-2.elb.amazonaws.com

The portion on the right is the endpoint to your Lambda. Hit that with curl: curl -v fubar-dev01-stack01-alb-123456789.us-west-2.elb.amazonaws.com

You should see something that includes lines similar to:

HTTP/1.1 200 OK OK
Server: awselb/2.0
Date: Wed, 26 Apr 2023 18:28:33 GMT
Content-Type: application/octet-stream

Note that content type should be application/json if this was working.

AWS Console

Go to the deployed Lambda in the AWS Console. Click on the 'Test' tab and look at the detailed response. It will look something like:

{
  "statusCode": 200,
  "multiValueHeaders": {
    "Content-Type": [
      "application/json"
    ],
    "Date": [
      "Wed, 26 Apr 2023 18:30:38 GMT"
    ]
  },

Note that that's appropriate for an API Gateway response, but not for a normal RESTful service. Also note that content type is correct here, but is buried in multiValuedHeaders.

Cleanup

Destroy what was deployed:

cd infra
cdk destroy -c config=dev01-stack01