aws to slack lambda function (node.js)

aws_to_slack.js

console.log('Loading function');

const https = require('https');
const url = require('url');
const slack_url = 'https://hooks.slack.com/xxxxx';
const slack_req_opts = url.parse(slack_url);
slack_req_opts.method = 'POST';
slack_req_opts.headers = {'Content-Type': 'application/json'};

exports.handler = function(event, context) {
  (event.Records || []).forEach(function (rec) {
    if (rec.Sns) {
      var req = https.request(slack_req_opts, function (res) {
        if (res.statusCode === 200) {
          context.succeed('posted 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);
      });

      // この辺で適当にslack postするテキストを調整する.
      var message = JSON.parse(rec.Sns.Message);
      var status = message.NewStateValue;
      if (status === "ALARM") {
          status = ":exclamation: " + status;
      }
      if (status === "OK") {
          status = ":+1: " + status;
      }
      var str = "*" +
                status +
                ": " +
                message.AlarmDescription +
                "*" +
                "\n" +
                message.NewStateReason;

      req.write(JSON.stringify({text: str}));

      req.end();
    }
  });
};