Send Code Deploy deployment status to Slack via SNS using a Lambda function

sns_to_slack.js

var https = require('https');
var util = require('util');

exports.handler = function(event, context){
  console.log(JSON.stringify(event, null, 2));
  console.log('From SNS:', event.Records[0].Sns.Message);

  var postData = {
    "channel": "#server-deploys",
    "username": "AWS SNS via Lambda",
    "text": "*" + event.Records[0].Sns.Subject + "*",
    "icon_emoji": ":aws:"
  };

  var message = JSON.parse(event.Records[0].Sns.Message);
  var severity = "good";
  
  var error_information = "No news, good news";
  var final_error = "";
  var formated_message = "";
  var deployment_status = message.status;

  if (deployment_status == "CREATED"){
    severity = "warning";
  }else if (deployment_status == "FAILED"){
    severity = "danger";
    error_information = JSON.parse(message.errorInformation);
  }

  if (typeof(error_information) == "string"){
    final_error = error_information;
  }else{
    final_error = error_information.ErrorMessage;
  }

  formated_message = message.deploymentGroupName + 
                     " deployment *" + 
                     message.status + 
                     "*. Deployment for " + 
                     message.applicationName + 
                     " in region " + 
                     message.region + 
                     ".\n\nError information: " + 
                     final_error;

  postData.attachments = [
    {
        "color": severity, 
        "text": formated_message
    }
  ];

  var options = {
    method: 'POST',
    hostname: 'hooks.slack.com',
    port: 443,
    path: '/services/[TOKEN]'
  };

  var req = https.request(options, function(res){
    res.setEncoding('utf8');
    res.on('data', function(chunk){
      context.done(null);
    });
  });
  
  req.on('error', function(e){
    console.log('problem with request: ' + e.message);
  });    

  req.write(util.format("%j", postData));
  req.end();
};