app.js

'use strict';
const conf = require( './config' );
var nodemailer = require( 'nodemailer' );
const requests = require( 'request' );
const fs = require( 'fs' );
const { date } = require('assert-plus');
const { config } = require('process');

var transporter = nodemailer.createTransport( {
    host: conf.sender_mail.host,
    secure: true,
    auth: {
        user: conf.sender_mail.user,
        pass: conf.sender_mail.pass
    },
    tls:{
        rejectUnauthorized: false
    }
});

let errorMessage = '';
let errorUrls = [];
let pleskError = false;

setInterval( async () => {
    requests({
        url: 'https://' + conf.plesk_host.hostname + ':8443/api/v2/domains',
        headers: {
            'Content-Type': 'application/json',
            'Authorization': 'Basic ' + conf.plesk_host.login_data
        }
    }, (error, response, domains) => {

        if( error ) {
            pleskError = true;
            return;
        }

        pleskError = false;
        domains = JSON.parse( domains );
        errorMessage = "";

        domains.forEach( domain => {
            if( domain.hosting_type != "virtual" || domain.name.includes( '*' ) )
                return;

            requests({
                url: 'https://' + domain.name,
            }, (error2, response2, body) => {

                if( conf.whitelisted_urls.includes( domain.name ) )
                    return;

                if( error2 ) {
                    let existing = errorUrls.find( url => url.domain === domain.name && url.statusCode === -1  );
                    if( existing )
                        existing.count++;
                    else
                        errorUrls.push( { statusCode: -1, domain: domain.name, count: 1 } );
                    return;
                }

                if( response2 != null ) {
                    if( response2.statusCode != 200 ) {
                        let existing = errorUrls.find( url => url.domain === domain.name && url.statusCode === response2.statusCode  );
                        if( existing )
                            existing.count++;
                        else
                            errorUrls.push( { statusCode: response2.statusCode, domain: domain.name, count: 1 } );    
                    }     
                    if( response2.statusCode == 200 ) {
                        let existingIndex = errorUrls.findIndex( url => url.domain === domain.name );
                        if( existingIndex != -1 )
                            errorUrls.splice(existingIndex, 1);
                    }
                }                   

            });
        });

    });
    sendMail();
}, 1000 * 60 * conf.period );



function sendMail() {

    let msg = '';
    if( !pleskError )
        msg = conf.receiver_mail.message_begin + '<br /><br />';
    else {
        msg = "Error connecting to plesk REST API!";
        fs.appendFile( 'error_log.txt', msg + '\n', () => {} );
    }

    if( errorUrls.length == 0 && !pleskError )
        return;

    let date = (new Date()).getFullYear() + '-' + ((new Date()).getMonth() + 1) + '-' + (new Date()).getDate() + ' ' + (new Date()).getHours() + ':' + (new Date()).getMinutes() + ':' + (new Date()).getSeconds();

    errorUrls.filter( url => url.count >= conf.checks_to_be_failed ).forEach( error => {
        let statusCode = error.statusCode;
        if( error.statusCode === -1)
            statusCode = 'Error fetching';
        
        msg += '<span style="color: red">' + statusCode + '</span> <a href="https://' + error.domain + '">https://' + error.domain + '</a> (' + error.count + ' pings)<br />';
    });
    errorUrls.forEach( error => 
        fs.appendFile( './monitoring_log.txt', date + " - " + error.statusCode + " " + error.domain + ' (' + error.count + ' pings)\n', () => {} )
    );

    var mailOptions = {
        from: conf.sender_mail.user,
        to: conf.receiver_mail.address,
        subject: conf.receiver_mail.subject,
        html: msg
    };
    if( msg != conf.receiver_mail.message_begin + '<br /><br />' )
        transporter.sendMail( mailOptions, (error, info) => {
            if ( error )
                fs.appendFile( 'error_log.txt', date + " - " + error + '\n', () => {} );
        });
}