s3files.js

'use strict';
const AWS = require('aws-sdk');
var s3 = new AWS.S3( { params: {Bucket: 'www-static.aws.roorkee.org', region: 'us-east-1'}});

module.exports.upload = async (event) => {
    
    let createResponse = (respObject, httpCode) => {
        return {
            statusCode: httpCode,
            body: JSON.stringify(respObject),
            headers: {
                'Content-Type': 'application/json',
                'Access-Control-Allow-Origin':'*',
                'Access-Control-Allow-Headers': '*',
                'Access-Control-Allow-Methods': 'GET, POST, OPTIONS, DELETE',
                "Access-Control-Allow-Credentials" : true,
                'Version':'17.10.15.4'
            }
        }
    }

    let uploadFile = async(event) => {
        let parsedBody = JSON.parse(event.body);
        let buf = new Buffer(parsedBody.data.replace(/^data:image\/\w+;base64,/, ""),'base64');

        var params = {
            Key: parsedBody.name, 
            Body: buf,
            ContentEncoding: parsedBody.type
        };
        
        try{
            var resp = await s3.putObject(params).promise();
            console.log(JSON.stringify(resp));
            return createResponse(resp, 200);
        }
        catch(err){
            console.log(JSON.stringify(err));
            return createResponse(err, 415)
        }
    }

    let getFilesList = async(event) => {
        var folder = `${event.pathParameters.env}/up/usr/${event.pathParameters.id}/`;
        console.log(`Folder ${folder}`);

        var params = { 
            Delimiter: '/',
            Prefix: folder,
            Bucket: 'www-static.aws.roorkee.org'
        }
        
        try{
            var listResp = await s3.listObjectsV2(params).promise();
            let files = [];
            if (listResp && listResp.Contents && listResp.Contents.length > 0){
                listResp.Contents.forEach(element => {
                    if (element.Size > 0){
                        files.push(element);
                    }
                });
            }
            return createResponse(files, 200);
        }
        catch(err){
            console.log(JSON.stringify(err));
            return createResponse(err, 415)
        }
    }

    if (event.httpMethod == 'POST'){
        return await uploadFile(event);
    }
    else if (event.httpMethod == 'GET'){
        return await getFilesList(event);
    }
    else{
        return createResponse({'message':'Unsupported HTTP method'}, 405)
    }
};