Amazon Lambda – E-mail via SNS the URL of an S3 file when created

I threw together the following Lambda function to send an e-mail via SNS (Amazon’s Simple Notification Service) whenever a file is created in S3 (Amazon’s Simple Storage Service.)  Yes, it’s barely commented and overly loggy, but you get the idea:

'use strict';

console.log('Loading function');

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 ${bucket}. Make sure they exist and your bucket is in the same region as this function.`;
 console.log(message);
 callback(message);
 } else {
 //console.log(err);
 const URLMessage = `https://s3-us-west-2.amazonaws.com/supportacdcalls/${key} `;
 const SuccessMessage = `Success getting object ${key} from bucket ${bucket}. `;
 console.log(SuccessMessage);
 console.log(URLMessage);
 //console.log('CONTENT TYPE:', data.ContentType);
 
 //Send SNS
 var sns = new aws.SNS();
 sns.publish({
 TopicArn: 'arn:aws:sns:us-west-2:xxxxxxxxxxxx:RecordingNotificationEmail',
 Message: JSON.stringify(URLMessage)
 }, function(err, data) {
 if(err) {
 console.error('error publishing to SNS');
 context.fail(err);
 } else {
 console.log('message published to SNS');
 context.done(null, data);
 }
 });
 
 
 
 callback(null, data.ContentType);
 }
 });
};