mssql.js

    /*
    MICROSOFT SQL
    */
    var sql = require(‘mssql’);
    var notifier = require(‘./notifier.js’)

    var config = {
        user: “username”,
        password: “Pass@word”,
        server: ‘mssql’,
        port : 1433,
        connectionTimeout : 10000
        }

    var poolPromise;

    getPool = () => {
        return poolPromise;
    }

    const limit_reconnect = 2;      /* or -1 for infinite */
    const delay_reconnect = 1000;   // delay in milliseconds between multiple tries
    var reconnect = 0;

    notifier.on(‘mssql_connect’, () => {
        new sql.ConnectionPool(config).connect()
            .then(pool => {
                poolPromise = pool;
                notifier.emit(‘mssql_connected’);
            })
            .catch(err => {
                notifier.emit(‘mssql_not_connected’);
            });
    });

    notifier.on(‘mssql_not_connected’, () => {
        reconnect++;
        if (limit_reconnect==-1 || reconnect<limit_reconnect) {
            setTimeout(function () {
                notifier.emit(‘mssql_connect’);
            }, delay_reconnect)
        }
        else {
            notifier.emit(‘mssql_connect_error’,‘failed to connect after ‘+limit_reconnect+’ tries …’);
        }
    });

    // startup — first try
    notifier.emit(‘mssql_connect’); // this also could be done in the main application …

    module.exports = {
        sql, getPool
    }