Send DynamoDB inserts of elmah logs to slack

elmah-dynamodb-lamda.js

console.log('Loading function');

const https = require('https');
const url = require('url');
// set up slack inbound webhook url
const slack_url = 'XXXXXXXXXXXX';
const slack_req_opts = url.parse(slack_url);
const elmah_details_url = 'https://website/elmah.axd/detail?id=';
slack_req_opts.method = 'POST';
slack_req_opts.headers = {'Content-Type': 'application/json'};

exports.handler = function(event, context) {
  //console.log("%j", event);
  var total = event.Records.length;
  var count = 0;

  (event.Records || []).forEach(function (rec) {
    console.log('received event:', rec.eventID);
    
    var req = https.request(slack_req_opts, function (res) {
      if (res.statusCode === 200) {
        count++;
        if(total === count) {
          console.log('posted all', count, 'records to slack');
          context.succeed('posted to slack');
        }
        else {
          console.log('posted', count, 'of', total, 'records to slack');
        }
      } else {
        context.fail('status code:', res.statusCode);
      }
    });
      
    req.on('error', function(e) {
      console.log('problem with request:', e.message);
      context.fail(e.message);
    });
      
    var dynamodb = rec.dynamodb;

    error = {
      errorId: dynamodb.Keys.ErrorId.S,
      type: dynamodb.NewImage.Type.S,
      message: dynamodb.NewImage.Message.S,
      user: (user = dynamodb.NewImage.User) ? user.S : null,
      link: elmah_details_url + dynamodb.Keys.ErrorId.S
    };

    fields = [];
      
    fields.push({
      title: 'type',
      value: error.type,
      short: true
    });
      
    if (error.user) {
      fields.push({
        title: 'user',
        value: error.user,
        short: true
      });
    }

    var payload = {
      attachments: [
        {
          title: error.message,
          title_link: error.link,
          fallback: error.message,
          fields: fields
        }
      ]
    }
    
    req.write(JSON.stringify(payload));
      
    req.end();
  });
}