AWS API Gateway Malformed Lambda Response

Question

The documentation states that the json should return containing a body,headers,and a status code all of which I have. However for whatever reason when I test it in API gateway it returns a malformed response.

This is the output of the method below it.

"{\\"body\\": 200, \\"headers\\": {\\"Content-type\\": \\"application/json\\"}, \\"statusCode\\": 200}"

def addnumbers(message, context):

    result = message['num1'] + 1
    print(result)
    resp = {
        "statusCode": 200,
         "body":  result,
        "headers": { "Content-type": "application/json"}
    }
    return (json.dumps(resp))

I am currently passing in num1=1 and it doesn't give any better error message. Any guidance would be appreciated.

Answer 1

Ok buckle in for an answer.

Make sure you have proxy integration enabled on whatever resource you want in your API.

Now go to your lambda. Look at how I was previously trying to pass in num1.I was trying to get it from the "Event" or message. This is where I was tripping up. Also note (you can't do a get with a body) Rather the input to the lambda should be like this.

{ "queryStringParameters": { "input": "Whatever the input is you want the lambda to test" } }

So now that we have our test configured for the lambda we need to code the lambda itself.

I put this code within :

def lambda_handler(event, context):

 number = "Hello, " + event['queryStringParameters']['input']

out = {}
out['statusCode'] = 200
out['body'] = number

return (out)

Now if you test it should be fine.

Go back to the API Gateway In the "Query Strings" Section put in input=randomname

It should now return with hello, randomname