fc_monitor_epl.js

   1 // monitor EPL and send an email if unreachable
   2
   3
   4 // Prerequisites
   5 var http = require('http');
   6 var Mailer = require('./mailer.js');
   7
   8 // globals
   9 var mailto = ['info@finalsclub.org', 'snow@sleepless.com'];
  10
  11 var msgs = [];
  12 function dlog(msg) {
  13         msgs.push(msg);
  14         console.log(msg);
  15 }
  16
  17
  18 function main() {
  19
  20         var numRetries = 2;
  21         var fc1Opts = {
  22                 host: 'finalsclub.org',
  23                 port: 9001,
  24                 path: '/',
  25                 method: 'GET',
  26                 timeout: 15 * 1000
  27         };
  28
  29         var errs = [];
  30
  31         var date = new Date().toString();
  32         var url = 'http://' + fc1Opts.host + ':' + fc1Opts.port + fc1Opts.path;
  33         dlog('FinalsClub EPL health check monitor');
  34         dlog('date: ' + date);
  35         dlog('url: ' + url);
  36         dlog('');
  37
  38         checkAlive(fc1Opts, numRetries, function (success, errMsg) {
  39                 var url = fc1Opts.host + ':' + fc1Opts.port + fc1Opts.path;
  40                 if (success) {
  41                         dlog('host is alive');
  42                         dlog('');
  43                 } else {
  44                         dlog('FAILED');
  45                         dlog('host is dead - final error: ' + errMsg);
  46                         dlog('');
  47
  48                         sendEmailAlert(url, msgs, date);
  49                 }
  50         });
  51 }
  52
  53 function checkAlive(httpOptions, retries, cb) {
  54         var errs = [];
  55         checkAlive2(httpOptions, retries, errs, cb);
  56 }
  57
  58 function checkAlive2(httpOptions, retries, errs, cb) {
  59         checkAliveWorker(httpOptions, function (success, errMsg) {
  60                 if (success || retries <= 0) {
  61                         cb(success, errMsg);
  62                 } else {
  63                         dlog('Error: ' + errMsg + '\n\nretrying...');
  64                         checkAlive2(httpOptions, retries - 1, errs, cb);
  65                 }
  66         });
  67 }
  68
  69 function checkAliveWorker(httpOptions, cb) {
  70
  71         var timeoutDelayMS = httpOptions.timeout || 30 * 1000;
  72
  73         // declare req var before using it's reference in timeout handler
  74         var req = null;
  75
  76         // init request timeout handler
  77         var timeoutId = setTimeout(function () {
  78                 clearTimeout(timeoutId);
  79
  80                 if (cb) {
  81                         cb(false, 'timeout');
  82                         cb = null;
  83                 }
  84                 req.abort();
  85         }, timeoutDelayMS);
  86
  87         // init request now
  88         req = http.request(httpOptions, function (res) {
  89                 // console.log('STATUS: ' + res.statusCode);
  90                 // console.log('HEADERS: ' + JSON.stringify(res.headers));
  91                 res.setEncoding('utf8');
  92                 res.on('data', function (chunk) {
  93                         // console.log('BODY: ' + chunk);
  94                         if (timeoutId) {
  95                                 clearTimeout(timeoutId);
  96                                 timeoutId = null;
  97                         }
  98
  99                         if (cb) { cb(true, null); }
 100                         cb = null;
 101                 });
 102
 103                 if (res.statusCode != 200) {
 104                         if (timeoutId) {
 105                                 clearTimeout(timeoutId);
 106                                 timeoutId = null;
 107                         }
 108
 109                         var msg = ['invalid response code',
 110                                                 'status: ' + res.statusCode,
 111                                                 'headers: ' + JSON.stringify(res.headers)];
 112
 113                         if (cb) { cb(false, msg.join('\n')); }
 114                         cb = null;
 115                 }
 116         });
 117
 118         req.on('error', function (e) {
 119                 console.log('problem with request: ' + e.message);
 120                 if (timeoutId) {
 121                         clearTimeout(timeoutId);
 122                         timeoutId = null;
 123                 }
 124
 125                 if (cb) { cb(false, e.message); }
 126                 cb = null;
 127         });
 128
 129         // close the request
 130         req.end();
 131 }
 132
 133
 134 function sendEmailAlert(url, msgs, date) {
 135         var awsAccessKey = process.env.AWS_ACCESS_KEY_ID;
 136         var awsSecretKey = process.env.AWS_SECRET_ACCESS_KEY;
 137         var mailer = new Mailer(awsAccessKey, awsSecretKey);
 138
 139         for (var i in mailto) {
 140                 var email = mailto[i];
 141                 dlog('sending email alert to: ' + email);
 142                 var details = msgs.join('\n');
 143                 var message = {
 144                         'to': email,
 145                         'subject': 'FinalsClub.org EPL Monitor Warning',
 146                         'template': 'systemEPLMonitorFailed',
 147                         'locals': {
 148                                 'url': url,
 149                                 'msgs': details,
 150                                 'date': date
 151                         }
 152                 };
 153
 154
 155                 mailer.send(message, function (err, result) {
 156                         if (err) {
 157                                 dlog('Error sending email\nError Message: ' + err.Message);
 158                         } else {
 159                                 dlog('Successfully sent email.');
 160                         }
 161                 });
 162         }
 163 };
 164
 165 main();
 166