json: cannot unmarshal object into Go struct field APIGatewayProxyRequest.body of type string on GET request about aws-lambda-go

[kkesley]

it turns out it's because I did not use lambda proxy integration. My bad.

[m1ch3lp3r3z]

Hi @kkesley I'm having the same issue after enabling lambda integration in my serverless.yml, because I need it for custom status codes (302). Could you please describe little more how you solved the problem?. Thank you!

[kkesley]

Hi @m1ch3lp3r3z TBH I made a mistake by not providing any details to my issue and I forgot about the issue I was having. Can you provide an example for your serverless.yml detail? I might still remember when I see your configuration.

[m1ch3lp3r3z]

Hi @kkesley, thank you for your quick reply. I'm trying to implement a lambda function that will receive data from a contact us form (application/x-www-form-urlencoded) and will return a 302 status code and Location header. My handler definition in serverless.yml looks like:

functions:
  contactUs:
    handler: go/bin/handlers/contact_us
    warmup:
      enabled: false
    events:
      - http:
          path: ${self:custom.apiVersion}/contact-us
          method: post
          cors: false
          integration: lambda
          response:
            statusCodes: 
              302:
                pattern: '' # Default response method
                headers:
                  Content-Type: "'text/html'"
                  Location: integration.response.header.location

Since I added the lambda integration I'm getting this error from the API Gateway:

{"errorMessage":"json: cannot unmarshal object into Go struct field APIGatewayProxyRequest.body of type string","errorType":"UnmarshalTypeError"}

The request is not even reaching my function so I'm guessing API Gateway is trying to parse the input as a JSON, but I fail to see where to change that.

Thank you!

[kkesley]

@m1ch3lp3r3z for me, I'm not using integration: lambda and just send the response in the code.

return events.APIGatewayProxyResponse{
		Body:            "some string",
		IsBase64Encoded: false,
		Headers: map[string]string{
			"Content-Type":                "text/plain",
			"Access-Control-Allow-Origin": "*",
		},
		StatusCode: 302,
	}, nil

[m1ch3lp3r3z]

@kkesley I actually started there, as soon as I set the StatusCode: 302 in my returned Response object I get "message": "Missing Authentication Token" (403). I think API Gateway by default only allows success or error status codes (out of the lambda fn). Wondering if you don't have any other configuration related to the status code 302 in your serverless.yml

[kkesley]

@m1ch3lp3r3z Hmm... I didn't set the response field in the serverless.yml. Is it only happening for 302 status code or can you test another one? e.g. 202 or 400?

[m1ch3lp3r3z]

Wow... the problem is the Location header, If I remove it I get the 302 status code through, but then how to tell the browser where to redirect to?

FYI 202 Accepted works good and probably 4XX too.

Thank you for the help!!