Uptime Event Emitter

An uptime event emitter for http and tcp servers.

Installation

npm install ping-monitor

How to use

const Monitor = require('ping-monitor');

const myWebsite = new Monitor(options);

myWebsite.on(event, function(response, state) {
    // Do something with the response
});

Methods

• stop - stop an active monitor
• restart - stop and start an active monitor

Options

• address - Server address to be monitored
• website - Website address to be monitored
• port - Server port (optional).
• interval (defaults to 15 mins) - time interval for polling requests.
• httpOptions - allows you to define your http/s request with more control. A full list of the options can be found here: https://nodejs.org/api/http.html#http_http_request_url_options_callback
• expect - allows you define what kind of a response you expect for your endpoint. At the moment expect accepts 1 prop (more to be added in future versions), statusCode a http status code.
• config { intervalUnits } - configuration for your Monitor, currently supports one property, intervalUnits. intervalUnits specifies which to time unit you want your Monitor to use. There are 4 options, milliseconds, seconds, minutes (default), and hours.
• ignoreSSL - ignore broken/expired certificates

Expect Object

expect {
  statusCode: Integer, // http status codes
  contentSearch: String
}

// http Get
const myApi = new Monitor({
    website: 'http://api.ragingflame.co.za',
    title: 'Raging Flame',
    interval: 5,

    config: {
      intervalUnits: 'minutes' // seconds, milliseconds, minutes {default}, hours
    },

    httpOptions: {
      path: '/users',
      method: 'get',
      query: {
        id: 3
      }
    },
    expect: {
      statusCode: 200
    }
});

// http Post
const myApi = new Monitor({
    website: 'http://api.ragingflame.co.za',
    title: 'Raging Flame',
    interval: 10,

    config: {
      intervalUnits: 'minutes' // seconds, milliseconds, minutes {default}, hours
    },

    httpOptions: {
      path: '/users',
      method: 'post',
      query: {
        first_name: 'Que',
        last_name: 'Fire'
      },
      body: 'Hello World!'
    },
    expect: {
      statusCode: 200
    }
});

Emitted Events

• up - All is good website is up.
• down - Not good, website is down.
• stop - Fired when the monitor has stopped.
• error - Fired when there's an error
• timeout - Fired when the http request times out

response object

• object.website - website being monitored.
• object.address - server address being monitored.
• object.port - server port.
• object.time - (aka responseTime) request response time.
• object.responseMessage - http response code message.
• object.responseTime - response time in milliseconds.
• object.httpResponse - native http/s response object.

state object

• object.id null - monitor id, useful when persistence.
• object.title null - monitor label for humans.
• object.isUp true - flag to indicate if monitored server is up or down.
• object.created_at <Date.now()> - monitor creation date.
• object.isUp true - current uptime status of the monitor.
• object.port null - server port.
• object.totalRequests 0 - total requests made.
• object.totalDownTimes 0 - total number of downtimes.
• object.lastDownTime <Date.now()> - time of last downtime.
• object.lastRequest <Date.now()> - time of last request.
• object.interval 5 - polling interval in minutes
• object.website null - website being monitored.
• object.address null - server address being monitored.
• object.port null - server port.

Website Example

'use strict';

const Monitor = require('ping-monitor');


const myMonitor = new Monitor({
    website: 'http://www.ragingflame.co.za',
    title: 'Raging Flame',
    interval: 10 // minutes
});


myMonitor.on('up', function (res, state) {
    console.log('Yay!! ' + res.website + ' is up.');
});


myMonitor.on('down', function (res) {
    console.log('Oh Snap!! ' + res.website + ' is down! ' + res.statusMessage);
});


myMonitor.on('stop', function (website) {
    console.log(website + ' monitor has stopped.');
});


myMonitor.on('error', function (error) {
    console.log(error);
});

TCP Example

'use strict';

const Monitor = require('ping-monitor');


const myMonitor = new Monitor({
    address: '162.13.124.139',
    port: 8080,
    interval: 5 // minutes
});


myMonitor.on('up', function (res, state) {
    console.log('Yay!! ' + res.address + ':' + res.port + ' is up.');
});


myMonitor.on('down', function (res, state) {
    console.log('Oh Snap!! ' + res.address + ':' + res.port + ' is down! ');
});


myMonitor.on('stop', function (res, state) {
    console.log(res.address + ' monitor has stopped.');
});


myMonitor.on('error', function (error, res) {
    console.log(error);
});


myMonitor.on('timeout', function (error, res) {
    console.log(error);
});

Change log

v0.6.1

Changes

• Added auto id generation opt-out

  let ping = new Monitor({
    website: 'https://google.com',
    interval: 5,
    config: {
      intervalUnits: 'minutes',
      generateId: false // defaults is true
    }
  });

  ping.on('up', function (res, state) {
    //state.id === null
    console.log('Yay!! Google is up');
  });


  ping.on('error', function (error, res) {
    console.error(error);
  });

v0.6.0

Changes

• Code refactoring
• Removed active from props (redundant)
• Removed host from props (not used)
• Added ignoreSSL to support websites with expired certificates

  let ping = new Monitor({
    website: 'https://wrong.host.badssl.com',
    interval: 1,
    config: {
      intervalUnits: 'minutes' // seconds, milliseconds, minutes {default}, hours
    },
    ignoreSSL: true
  });

  ping.on('up', function (res, state) {
    console.log('Yay!! Service is up');
  });


  ping.on('error', function (error, res) {
    console.error(error);
  });

v0.5.2

Changes

• Added support for configuring interval units

  let ping = new Monitor({
    website: 'https://webservice.com',
    interval: 1,
    config: {
      intervalUnits: 'minutes' // seconds, milliseconds, minutes {default}, hours
    }
  });

  ping.on('up', function (res, state) {
    console.log('Yay!! Service is up');
  });


  ping.on('error', function (error, res) {
    console.error(error);
  });

v0.5.1

Changes

• Added Support for content search in HTTP/HTTPS - courtesy of @pbombnz

  let ping = new Monitor({
    website: 'https://ecommorce-shop.com/playstation5',
    interval: 0.1,
    expect: {
      contentSearch: 'In stock'
    }
  });

  ping.on('up', function (res, state) {
    console.log('Yay!! Content cantains the phrase "In stock"');
  });


  ping.on('error', function (error, res) {
    console.error(error);
  });

v0.5.0

Changes

• Added timeout event to Monitor instance. This event is passed from the htt/s module.

  myMonitor.on('timeout', function (error, res) {
    console.log(error);
  });

  // also make sure that you are handling the error event
  myMonitor.on('error', function (error, res) {
    console.log(error);
  });

• Dependencies update

Please note: When the timeout event is fired, it is followed by the error event which is created when we manually abort the http request.

v0.4.4

Dependencies update

v0.4.3

Changes

• Added the native http/s response object in the Monitor response object
• Added Post support in your Monitor instances.

You can now include a body in your httpOptions:

// http Post
const myApi = new Monitor({
    website: 'http://api.ragingflame.co.za',
    title: 'Raging Flame',
    interval: 10 // minutes

    // new options
    httpOptions: {
      path: '/users',
      method: 'post',
      query: {
        first_name: 'Que',
        last_name: 'Fire'
      },
      body: 'Hello World!'
    },
    expect: {
      statusCode: 200
    }
});

myApi.on('up', function (res, state) {
  /*
    response {
      responseTime <Integer> milliseconds
      responseMessage <String> response code message
      website <String> url being monitored.
      address <String> server address being monitored
      port <Integer>
      httpResponse <Object> native http/s response object
    }

    state {
      created_at <Date.now()>
      isUp <Boolean>
      port: <Integer>
      totalRequests <Integer>
      lastDownTime <Date.now()>
      lastRequest <Date.now()>
      interval <Integer>
    }
  */
});

v0.4.2

Changes

Added some utility methods used when updating a monitor and added immediate ping on monitor creation.

• Added pause method to Monitor.
• Added unpause method to Monitor.

Tip: See options section to learn how they work.

v0.4.1

Changes

Changes in v0.4.1 give you more control to define your http requests and what response to expect.

• Added httpOptions prop to Monitor instance options.
• Added expect prop for naming your your monitor.

Tip: See options section to learn how they work.

v0.4.0

Changes

Most of the changes introduced in this version were introduced to support database persistence.

• Added id prop, useful when you add database persistence.
• Added title prop for naming your your monitor.
• Added active prop to flag if monitoring is active.
• Added totalDownTimes prop for keeping record of total downtimes.
• Added isUp prop to indicate if monitored server is up or down.
• Added website, address, totalDownTimes, active, active props to the emitted state object
• Added eslinting (2015) and cleaned up the code a bit
• *breaking change: * the stop event now takes a callback that accepts 2 arguments, response && state (same as the up and down events).

v0.3.1

New Feature

• Added a state object in the response that returns useful monitoring data

• State object

  const Monitor = require('ping-monitor');

  const myMonitor = new Monitor(options);

  myMonitor.on(event, function(response, state) {
    /*
      response {...}
      state {
        created_at <Date.now()>
        isUp <Boolean>
        port: <Integer>
        totalRequests <Integer>
        lastDownTime <Date.now()>
        lastRequest <Date.now()>
        interval <Integer>
      }
    */
  });

Changes made

• The event handler now accepts to arguments response and state, please see above examples.

v0.3.0

• Brought back error event - required for handling module usage related errors
• Added responseTime to the response object
• Added support for tcp servers

v0.2.0

• Code cleanup and upgrade to ES6
• Removed the error event - now being handled internally
• Bug fixed: Unreachable resource not handled #9

Testing

npm test

License

(MIT License)

Copyright (c) 2013 - 2018 Qawelesizwe Mlilo [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.