monitor.js

var assert = require('assert');
var request = require('request');  
var util = require('util');
const requestPromise = util.promisify(request);

var urlsToMonitor = ['https://blog.newrelic.co.jp/', 'https://docs.newrelic.co.jp/'];

var insightKey = $secure.INSIGHTKEY;
var accountId = $secure.ACCOUNTID;

function treatAsUTC(date) {
    var result = new Date(date);
    result.setMinutes(result.getMinutes() - result.getTimezoneOffset());
    return result;
}

function daysBetween(startDate, endDate) {
    var millisecondsPerDay = 24 * 60 * 60 * 1000;
    return Math.round((treatAsUTC(endDate) - treatAsUTC(startDate)) / millisecondsPerDay);
}

function insertInsightsEvent(urlMonitored, certificateIssuer, daysToExpiration, expirationMilliseconds){
  var options = {
    uri: `https://insights-collector.newrelic.com/v1/accounts/${accountId}/events`,
    body: JSON.stringify([{
            'eventType': 'SSLCertificateCheck',
            'Url': urlMonitored,
            'Issuer': certificateIssuer,
            'DaysToExpiration': daysToExpiration,
            'ExpirationDate': expirationMilliseconds
        }
    ]),  
//    '[{"eventType":"SSLCertificateCheck","Url":"'+urlMonitored+'","Issuer":"'+certificateIssuer+'","DaysToExpiration":'+daysToExpiration+', "ExpirationDate":'+expirationMilliseconds+'}]',
    headers:{
        'X-Insert-Key': insightKey,
        'Content-Type': 'application/json'
    }
  };
  console.log("Posting event for: "+urlMonitored);
  request.post(options, function(error,response, body){
      console.log(response.statusMessage);
      console.log(`status code: ${response.statusCode}`);
      assert.ok(response.statusCode == 200, `${urlMonitored}のInsight Custom Eventの送信ステータスが200以外です`);  
      var info = JSON.parse(body);
      assert.ok(info.success == true, `${urlMonitored}のInsight Custom Eventの送信結果にtrue以外のレスポンスが含まれています: ${info.success}`);
      console.log('SSL cert check が完了してCustom Eventの送信が完了しました');
    });
}

function processSite(urlToMonitor)
{
  console.log(`チェック対象のサイト]: ${urlToMonitor}`);  

  var options = {
    url: urlToMonitor,
    method: 'HEAD',
    gzip: true,
    followRedirect: false,
    followAllRedirects: false
  };

  requestPromise(options).then((response) => {
    var certDetails = (response.req.connection.getPeerCertificate());
    var currentDate = new Date();
    var certExpirationDate = new Date(certDetails.valid_to);
    var daysToExpiration = daysBetween(currentDate, certExpirationDate);
    var certificateIssuer = certDetails.issuer.O;
  
    console.log(`証明書発行元: ${certificateIssuer}`);   
    console.log(`証明書期限日 ${certExpirationDate}`);   
    console.log(`テスト実施日: ${currentDate}`);
    console.log(`失効するまであと ${daysToExpiration}日`);
    console.log(`${options.url}のCustom EventをInsightに送信します...`);
      
    insertInsightsEvent(options.url, certificateIssuer, daysToExpiration, certExpirationDate.getTime());
  }).catch((error) => {
    assert.fail(error);
  });
}

urlsToMonitor.forEach(url => {processSite(url)});