AWS Lambda Function to send an SMS message via the Twilio API

AWSLambdaSimpleSMS.js

console.log('Loading event');

// Twilio Credentials 
var accountSid = '';
var authToken = '';
var fromNumber = '';

var https = require('https');
var queryString = require('querystring');

// Lambda function:
exports.handler = function (event, context) {

    console.log('Running event:', event);

    // Send an SMS message to the number provided in the event data.
    // End the lambda function when the send function completes.
    SendSMS(event.to, event.body,
                function (error, response) { context.done(error, response); });
};

// Sends an SMS message using the Twilio API
// to: Phone number to send to
// body: Message body
// completedCallback(status) : Callback with status message when the function completes.
function SendSMS(to, body, completedCallback) {

    // The SMS message to send
    var message = {
        To: to,
        From: fromNumber,
        Body: body
    };

    var messageString = queryString.stringify(message);

    // Options and headers for the HTTP request
    var options = {
        host: 'api.twilio.com',
        port: 443,
        path: '/2010-04-01/Accounts/' + accountSid + '/Messages.json',
        method: 'POST',
        headers: {
                    'Content-Type': 'application/x-www-form-urlencoded',
                    'Content-Length': Buffer.byteLength(messageString),
                    'Authorization': 'Basic ' + new Buffer(accountSid + ':' + authToken).toString('base64')
                 }
    };

    // Setup the HTTP request
    var req = https.request(options, function (res) {

        res.setEncoding('utf-8');

        // Collect response data as it comes back.
        var responseString = '';
        res.on('data', function (data) {
            responseString += data;
        });

        // Log the responce received from Twilio.
        // Or could use JSON.parse(responseString) here to get at individual properties.
        res.on('end', function () {
            console.log('Twilio Response: ' + responseString);
            var r = JSON.parse(responseString);
            if (!r.sid) {
                completedCallback(JSON.stringify(r));
            } else {
                completedCallback(null, r);
            }
        });
    });

    // Handler for HTTP request errors.
    req.on('error', function (e) {
        console.error('HTTP error: ' + e.message);
        completedCallback(JSON.stringify(e));
    });

    // Send the HTTP request to the Twilio API.
    // Log the message we are sending to Twilio.
    console.log('Twilio API call: ' + messageString);
    req.write(messageString);
    req.end();

}

cloud-code-function.js

function getTwilioClient() {
    return {
        sendSms: function(data, callback) {
            var url = 'YOUR_AWS_API_GATEWAY_ENPOINT';

            Parse.Cloud.httpRequest({
                method: 'POST',
                url: url,
                body: data,
                headers: {
                    "Content-Type": "application/json",
                    "x-api-key": 'YOUR_AWS_API_GATEWAY_API_KEY'
                },
                success: function(res){
                    var json = JSON.parse(res.text);
                    if (json.errorMessage) {
                        callback(JSON.parse(json.errorMessage));
                    } else {
                        callback(null, json);
                    }
                },
                error: function(res){
                    console.log('ERROR RESPONSE: ' + JSON.stringify(res))
                    callback({
                        status: -1,
                        data: res.text
                    });
                }
            });
        }
    };
}

var client = getTwilioClient();
client.sendSms({
        to: to,
        body: body
    },
    function(error, responseData){
      // handle response
    }
  });