NodeJS: Getting the S3 object content with the AWS Lambda Function

aws-lambda-s3-get-content-object.js

var aws = require('aws-sdk');
var s3 = new aws.S3();

exports.handler = (event, context, callback) => {
    
    //Verifica se o objeto existe (chamada através de evento no S3)
    if ((event) && (event.Records) && (event.Records[0]) && (event.Records[0].s3) && (event.Records[0].s3.bucket) && (event.Records[0].s3.object)){
        
        //Recupera informações de bucket e do objeto
        var _bucket = event.Records[0].s3.bucket.name;
        var _key = event.Records[0].s3.object.key;
        
        if ((_bucket) && (_key)){
            
            var _content = null;
            getContentObject(_bucket, _key).then(function(v) { // `delay` returns a promise
                _content = v;
                
                //Verifica se tem conteúdo no arquivo
                if(_content){
                    /*TODO */
                }
                else {
                    deleteObject(_bucket, _key);
                }
            }).catch(function(v) {
                
                //Se ocorreu algum erro na leitura do arquivo, então remove o arquivo do bucket
                deleteObject(_bucket, _key);  
            });
        }    
    }
    
    // TODO implement
    callback(null, 'Hello from Lambda');
};


function getContentObject(bucket, key){
    return new Promise(function(resolve, reject) {
        // Only `delay` is able to resolve or reject the promise
        s3.getObject({ Bucket: bucket, Key: key}, function(err, data) {
            if (err){ 
                console.log(err, err.stack); 
                resolve(null);
            }    
            else {
                resolve(data.Body.toString('utf-8'));
            }
        });   
    });
}

function deleteObject(bucket, key){
    s3.deleteObject({ Bucket: bucket, Key: key}, function(err, data) {
        if (err) console.log(err, err.stack);
        else     console.log(data);
    });
}