How to upload an object into Amazon S3 in Lambda

Question

Can't seem to upload an object into S3 in Lambda. Everything works fine locally. No errors in logs that would show what's going wrong.

Code below:

console.log('Loading function');
var AWS = require('aws-sdk');
var s3 = new AWS.S3();

exports.handler = function(event, context) {
    //console.log(JSON.stringify(event, null, 2));
    var s3 = new AWS.S3();
    var param = {Bucket: 'flow-logs', Key: 'test-lambda-x', Body: 'me me me'};
    console.log("s3");
    s3.upload(param, function(err, data) {
        if (err) console.log(err, err.stack); // an error occurred
        else console.log(data);           // successful response
    });
    console.log('done');
    context.done();
};

Runs successfully without error, but the callback in s3.upload doesn't seem to be called. No object in the bucket is created.

Verified IAM role permissions weren't a problem by granting full access, as well as testing out locally.

Answer 1

I suspect you are calling the context.done() function before s3.upload() has a chance to return. If you move context.done() into the upload response code block, it should work.

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

exports.handler = function(event, context) {
    //console.log(JSON.stringify(event, null, 2));
    var s3 = new AWS.S3();
    var param = {Bucket: 'flow-logs', Key: 'test-lambda-x', Body: 'me me me'};
    console.log("s3");
    s3.upload(param, function(err, data) {
        if (err) console.log(err, err.stack); // an error occurred
        else console.log(data);           // successful response

        console.log('actually done!');
        context.done();
    });

    console.log('done?');
    //context.done();
};