How to parse body params on AWS lambda?

Question

On my AWS lambda function i have access to an event json which holds a parameter called: body. the issue is this is a raw body string (not parsed into individual parameters).

{
  input: {
    body: "------WebKitFormBoundarys3wLu6HlaCBrIExe\r\nContent-Disposition: form-data; name=\"foo\"\r\n\r\nbar\r\n------WebKitFormBoundarys3wLu6HlaCBrIExe\r\nContent-Disposition: form-data; name=\"media[]\"\r\n\r\nhthtth\r\n------WebKitFormBoundarys3wLu6HlaCBrIExe\r\nContent-Disposition: form-data; name=\"media[]\"\r\n\r\nlololol\r\n------WebKitFormBoundarys3wLu6HlaCBrIExe--\r\n"
  }
}

I'd like to take that and turn into:

{
  foo: 'bar',
  media: [
    "grgkoerpkge",
    "twepgbopcib"
  ]
}

I'd prefer not to use some bloated express server just to parse a body string.

P.S. I've tried to use body-parser but it seems like it only works with express as a middleware

You can find the solution [here](https://stackoverflow.com/questions/38599028/parse-multipart-form-data-from-body-as-string-on-aws-lambda) — sayan saha, Nov 01 '20 at 00:43

score 1 · Answer 1 · answered Oct 14 '21 at 08:44

1

const {URLSearchParams} = require('url')
const sp = new URLSearchParams(event.body)

answered Oct 14 '21 at 08:44

Oded Breiner

28,523
10
105
71

score 0 · Answer 2 · answered Jun 11 '20 at 15:39

0

Encountered similar issue recently, as content-type in request was plain text format, I used querystring, built in module in node js to parse body string, more about querystring

const querystring = require('querystring');

& in lambda handler,

var jsonData = querystring.parse(event.body);

answered Jun 11 '20 at 15:39

dc7

401
1
4
13

This only works when the body `Content-Type` is `application/x-www-form-urlencoded`, doesn't work for `multipart/form-data`. – sayan saha Oct 31 '20 at 23:30

score -1 · Answer 3 · answered Aug 07 '17 at 05:57

-1

Send it to your lambda as JSON.

Then, in your lambda (if you use lambda-proxy integration), parse it by using JSON.parse(event.body).

answered Aug 07 '17 at 05:57

Noel Llevares

15,018
3
57
81

2

I can't control what's sent to me - it's a webhook from a service – CodeOverload Aug 07 '17 at 20:20

score -1 · Answer 4 · answered Aug 13 '17 at 21:08

-1

You'r passing the params by form or with the "Content-Type" in the header "application/x-www-form-urlencoded".

You shoukd pass it with "application/json"

answered Aug 13 '17 at 21:08

Guerra

2,792
1
22
32

How to parse body params on AWS lambda?

4 Answers4