AWS API Gateway Binary Corruption

Question

I have a problem whereby my API Gateway + Lambda Integration is undergoing some form of content mapping by the API Gateway.

I have API Gateway with an endpoint which is using the Lambda Proxy Integration.

I have enabled the Binary Media Types: image/jpeg image/png image/webp image/* /

The endpoint takes an images, optimizes it to jpeg or webp depending on what browser you are using.

With Firefox it returns the image/jpeg as expected.

Viewing in Chrome (which returns the webp file) results in a square box being returned. (This all works on Elastic Beanstalk, so I know it is a gateway problem)

In Chrome I can see some sort of mapping is happening:

content-length: 4710
content-type: image/webp
status: 200
x-amz-apigw-id: UEG2ZE8vDoEFR8A=
x-amzn-remapped-content-length: 2580
x-amzn-requestid: 6217195f-20ae-11e9-9faf-ebf6a6f5765d
x-amzn-trace-id: Root=1-5c4b1e8f-cab2e4fd2564412ef5914509;Sampled=0

The value: x-amzn-remapped-content-length Is the length that should be returned. I'm not sure what processes is skewing the return of the data.

Proxy Integration Setup

API Gateway Configuration

Doolali Doolali · Accepted Answer · 2019-01-30T20:07:40

For anyone else stuck on this issue, I needed to register the binary types in my Lambda Entry Point, see below:

public class LambdaEntryPoint : Amazon.Lambda.AspNetCoreServer.APIGatewayProxyFunction
{
    protected override void Init(IWebHostBuilder builder)
    {
        // Register any MIME content types you want treated as binary
        RegisterResponseContentEncodingForContentType("image/jpeg", ResponseContentEncoding.Base64);
        RegisterResponseContentEncodingForContentType("image/webp", ResponseContentEncoding.Base64);
        RegisterResponseContentEncodingForContentType("image/png", ResponseContentEncoding.Base64);

        builder
            .UseStartup<Startup>();
    }
}

AWS API Gateway Binary Corruption

1 Answers