aPulse

A one-file NodeJS server status monitoring/notification tool.

Demo

Visit https://apulse.ybouane.com for a demo!

Features

• Highly and easily configurable, edit the config.js file to add test endpoints and configure the watcher
• Supports sending outage notifications by: Telegram, Discord, Slack, SMS (Twilio API), Email (SendGrid API)
• Uses the Fetch API to test server-responses, you can configure GET, POST, PUT... requests and have full control over the fetch options.
• Check content for validity, HTTP status...
• Measures latency
• Minimal and easy to use dashboard
• Easy to setup. Run the watcher.js script and open the static/index.html page to view the dashboard.
• Auto-reload of the config file (no need to restart the watcher)
• No dependencies

How does it work

aPulse can be configured through the "config.js" file and it looks like this

export default {
    interval            : 15, // Interval in minutes between each pulse
    nDataPoints         : 90, // Number of datapoints to display on the dashboard
    responseTimeGood    : 300, // In milliseconds, this and below will be green
    responseTimeWarning : 600, // In milliseconds, above this will be red
    timeout             : 5000, // In milliseconds, requests will be aborted above this
    verbose             : true, // Whether or not to output pulse messages in the console
    readableStatusJson  : true, // Format status.json to be human readable
    logsMaxDatapoints   : 200, // Maximum datapoints history to keep (per endpoint)
    telegram            : {}, // optional, tokens to send notifications through telegram
    slack               : {}, // optional, tokens to send notifications through slack
    discord             : {}, // optional, tokens to send notifications through discord
    twilio              : {}, // optional, tokens to send notifications through twilio (SMS)
    sendgrid            : {}, // optional, tokens to send notifications through sendgrid (Email)
    consecutiveErrorsNotify         : 1, // After how many consecutive Errors events should we send a notification
    consecutiveHighLatencyNotify    : 3, // After how many consecutive High latency events should we send a notification
    sites               : [ // List of sites to monitor
        {
            id              : 'google', // optional
            name            : 'Google',
            endpoints       : [ // Each site is a bunch of endpoints that can be tested
                {
                    id              : 'homepage', // optional
                    name            : 'Homepage', // optional
                    link            : 'https://www.google.com', // optional, for notifications and dashboard only, [defaults to endpoint.url], can be disabled by setting it to false
                    url             : 'https://www.google.com', // required
                    request         : { // optional, fetch options
                        method: 'GET',
                    },
                    mustFind        : 'Feeling Lucky', // optional, String | Array | Regex | Function | AsyncFunction
                    mustNotFind     : /Page not found/i, // optional, String | Array | Regex | Function | AsyncFunction
                    customCheck     : async (content, response)=>{return true;}, // optional, Function | AsyncFunction -> Run your own custom checks return false in case of errors
                    validStatus     : [200], // optional, Which http status should be considered non errors [defaults to 200-299]
                }
            ]
        }
    ],
};

Installation

Clone the repo:

git clone https://github.com/ybouane/aPulse.git

Either run the watcher.js script directly (you need to keep it running in the background)

cd aPulse

node watcher.js

Or use a tool like PM2 (prefered method):

npm install pm2 -g

Start watcher.json

pm2 start pm2.json

Configure pm2 to automatically start during startup

pm2 startup

Save current pm2 processes list

pm2 save

Serving the status page

The watcher.js script only takes care of running the status checks and updates the status.json file in the static/ folder. If you want to view the final result, you simply need to serve the files in the static/ folder. You can use Nginx with a config like:

# Pulse
server {
    root /var/www/apulse/static/;
    index index.html;
    server_name apulse.ybouane.com;
    location /favicon.ico {
        return 301 "/favicon.png";
    }
    listen 80;
}

Or use any other tool to serve those files like the npm http-server package:

cd static
npx http-server -o ./