Problems with "Accept-Encoding: br" header

[phbender]

I have deployed a lambda bwhind API Gateway using axum etc., have been happy for a couple of minutes and now am completely lost.

This works:

• curl -H "Accept-Encoding: gzip, deflate" -i https:/my-api

This does not work:

• curl -H "Accept-Encoding: gzip, deflate, br" -i https:/my-api
• (note the br encoding here)

What I observe:

• The Gateway logs tell me that the handler has returned a 200 and a byte size which I totally expect (5 for hello response)
• The browser (or curl, ...) tells me 503.

HTTP/2 503 
date: Tue, 06 Dec 2022 15:37:19 GMT
content-length: 35
apigw-requestid: cuwzYlQfoAMEJXQ=

{"message":"Internal Server Error"}%  

Does this sound familiar to someone here? The fact that the logs show the "correct" reponse tells me that the lambda either does not see or at least not act based on that header (indicator: the size). On the other hand I cannot imagine AWS having problems with br encoding.

[bnusunny]

Hello, this should work. Are you using REST API endpoint?

[phbender]

Hi bnsunny, I found the error, it has been very subtle. See answer below.

[phbender]

I specified the payload format version to be "1.0" instead of "2.0". I read about this parameter before but I would have expected it to explode with much more noise.

Double checked: by switching back and forth between both settings, I get the behaviour described above.

Bottom line: To deploy a Lambda handler using this crate, it can be deployed using code like this:

resource "aws_apigatewayv2_api" "lambda" {
  name          = "some-gateway-name"
  protocol_type = "HTTP"
}

resource "aws_apigatewayv2_stage" "lambda" {
  api_id = aws_apigatewayv2_api.lambda.id

  name        = "v1"
  auto_deploy = true
}

resource "aws_apigatewayv2_integration" "lambda_app" {
  api_id = aws_apigatewayv2_api.lambda.id

  integration_uri    = aws_lambda_function.lambda_app.invoke_arn
  integration_type   = "AWS_PROXY"
  integration_method = "POST"
  payload_format_version = "2.0"
}

[bnusunny]

Yeah, for HTTP Endpoint, only payload format version 2.0 is supported.