在AWS ApiGateway上找不到JSONObject [\\“ body \\”]

Question

I'm developing an API Gateway to get data (image) from a sensor and send to DynamoDB at AWS. I already have the endpoint and API key. However, I get the following error when testing the API:

Request: /?image=12345  
Status:  
Latency: ms  
Response Body  
{  
  "cause": "JSONObject[\"body\"] not found.",  
  "logref": "12345-11d8-888888",  
  "message": ""  
}  

IAM roles and policies are ok. The Python code posts via requests the following payload

payload={"image": [1,2,3,4,5]}

Given that:

requests.posts(API_URL,files=payload,headers={'api-key':'12345abcd'})

My Body Mapping Template is:

{"body" : $input.json('$')}

But this Body Mapping is generating an alert in Request Body of GET (inappropriate request validator).

As you can see in the following image, I'm getting 4xx errors for all API Requests.

DynamoDB is not receiving the payload. Can someone give me a slight idea of the possible causes for this?

Answer 1

I found the solution. There were a couple of things to be fixed:

1 - I mapped the JSON correctly using: https://www.liquid-technologies.com/online-json-to-schema-converter

So, for:

{
  "MessageID" : {
    "S" : "12345"
  },
  "type" : {
"S" : "type"
  },
  "page" : {
"S" : "page"
  }
}

... sent by Python, the body mapping became:

{
  "MessageID" : {
    "S" : "$input.params('MessageID')"
  },
  "type" : {
    "S" : "$input.params('type')"
  },
  "page" : {
    "S" : "$input.params('page')"
  }
}

And the model:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "MessageID": {
      "type": "object",
      "properties": {
        "S": {
          "type": "string"
        }
      },
      "required": [
        "S"
      ]
    },
    "type": {
      "type": "object",
      "properties": {
        "S": {
          "type": "string"
        }
      },
      "required": [
        "S"
      ]
    },
    "page": {
      "type": "object",
      "properties": {
        "S": {
          "type": "string"
        }
      },
      "required": [
        "S"
      ]
    }
  },
  "required": [
    "MessageID",
    "type",
    "page"
  ]
}

Now I get:

<Response [200]>
ok
<Response [200]>
ok
<Response [200]>
ok
<Response [200]>
ok
<Response [200]>
ok
<Response [200]>
ok
<Response [200]>
ok
<Response [200]>
ok

And data is arriving at DynamoDB via Lambda function, clean and formatted, with no logs errors in API Gateway.