Serve zip file from AWS Lambda

Question

I need an endpoint (serverless) that serves a series of files compressed in a zip file. To do this I am using node-zip. This works locally to create a simple zip file with a flat file text:

const fs = require('fs')
const zip = new require('node-zip')()

const flat_text = 'This is a flat text file'

zip.file('a_file.txt', flat_text)
fs.writeFileSync('/tmp/a_file.zip', zip.generate({base64: false, compression: 'DEFLATE'}), 'binary')

But when I try to implement it in a lambda the downloaded zip file is corrupted:

module.exports.weekly = async (event, context) => {
    const flat_text = 'This is a flat text file'
    zip.file('a_file.txt', flat_text)
    return {
        headers: {
            'Content-Type': 'application/zip, application/octet-stream',
            'Content-disposition': `attachment; filename=${`any_name_${new Date().toJSON().slice(0, 10)}.zip`}`
        },
        body:  zip.generate({base64: false, compression: 'DEFLATE'}),
        statusCode: 200
    }
}

Why do I get a corrupted zip file?

Update

What I did in the end to fix this:

Change the body of the request to a base64 string (jszip: generateAsync({type: 'base64'}))
Make the API Gateway serve binary content: https://medium.com/nextfaze/binary-responses-with-serverless-framework-and-api-gateway-5fde91376b76

Did you try adding `isBase64Encoded : true` in the response object? — A.Khan, Feb 04 '19 at 15:19
@AtharKhan since the zip is not generated as a base64 string I didnt try that — Purefan, Feb 04 '19 at 15:36
@AtharKhan but I switched to base 64 when generating the zip and when sending the response and that worked. If you write it as a response I will mark it as correct. Thank you! — Purefan, Feb 04 '19 at 15:37
@onassar I no longer have access to that codebase but it was pretty straightforward, are you having problems with node-zip? — Purefan, Sep 09 '21 at 22:12
Ended up just going directly w/ `jszip` so it's fine. thanks for the reply! — onassar, Sep 10 '21 at 06:03

score 4 · Accepted Answer · answered Feb 04 '19 at 15:42

4

You can try encoding the response as Base64 encoded string by adding isBase64Encoded: true in the response object.

answered Feb 04 '19 at 15:42

A.Khan

3,826
21
25

score 0 · Answer 2 · answered Dec 01 '20 at 09:45

0

The Easiest way to do it is by Zipping the file and putting in back in the same bucket and then getting SignedUrl for that file.

answered Dec 01 '20 at 09:45

yodellingbutters

285
6
20

Serve zip file from AWS Lambda

Update

2 Answers2