Extract zip file from S3 bucket with AWS Lambda function with Node.js and upload to another bucket

Question

Iam playing with AWS Lambda with Node.js. I have created a lambda function and configure it with S3 event. I want to extract zip file which is uploaded on S3 and upload extracted file to another folder on same bucket.

I am getting the bucket and file information from following code but after that I don't know how to extract and upload to s3.

Any suggestion or chunk of code will be helpful for me.

'use strict';

console.log('Loading function to get all latest object from S3 service');

const aws = require('aws-sdk');

const s3 = new aws.S3({ apiVersion: '2006-03-01' });


exports.handler = (event, context, callback) => {
    console.log('Received event:', JSON.stringify(event, null, 2));

    // Get the object from the event and show its content type
    const bucket = event.Records[0].s3.bucket.name;
    const key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, ' '));
    const params = {
        Bucket: bucket,
        Key: key,
    };
    s3.getObject(params, (err, data) => {
        if (err) {
            console.log(err);
            const message = `Error getting object ${key} from bucket ${bucket}. Make sure they exist and your bucket is in the same region as this function.`;
            console.log(message);
            callback(message);
        } else {
            console.log('CONTENT TYPE:', data.ContentType);
            callback(null, data);
        }
    });
};

Answer 1

You can use zlib to unzip the buffer that you get from s3.

s3.getObject(params, (err, data) => {
    if (err) {
        console.log(err);
        const message = `Error getting object ${key} from bucket ${bucket}. Make sure they exist and your bucket is in the same region as this function.`;
        console.log(message);
        callback(message);
    } else {
        zlib.gunzip(data.Body, function (err, result) {
            if (err) {
                console.log(err);
            } else {
                var extractedData = result;
                s3.putObject({
                Bucket: "bucketName",
                Key: "filename",
                Body: extractedData,
                ContentType: 'content-type'
                }, function (err) {
                     console.log('uploaded file: ' + err);
                });
            }
        });
    }
});

I think the above function will help you.