projeto-hit/TEST_SERVER1/whats/helpers/mysql_conn.js

const dotenv = require('dotenv');
dotenv.config({ path: `${process.cwd()}/.env` });
const path = require('path')   


// Ubicua Plataform - MYSQL Module
try{
    var mysql_npm = require('mysql');
}catch(err){
    console.log("Cannot find `mysql` module. Is it installed ? Try `npm install mysql` or `npm install`.");
}


var db_config = {
        host         : process.env.DB_HOST,
        user         : process.env.DB_USER,
        password     : process.env.DB_PASS,
        database     : process.env.DB,
        charset      : 'utf8mb4_general_ci',        
        port         : process.env.DB_PORT
    };

//-
//- Connection configuration
//-
// var db_config = {
//     host         : 'localhost',
//     user         : 'whaticket',
//     password     : '9147teste',
//     database     : 'db_cdnwork',
//     charset      : 'utf8mb4_general_ci',
//     port         : '6603'
// };




// var db_config = {
//     host         : '172.31.187.7',
//     user         : 'todoo',
//     password     : '7901228899',
//     database     : 'db_cdnwork',
//     charset      : 'utf8mb4_general_ci'
// };
 


//-
//- Create the connection variable
//-
var connection = mysql_npm.createPool(db_config);


//-
//- Establish a new connection
//-
connection.getConnection(function(err){
    if(err) {
        // mysqlErrorHandling(connection, err);
        console.log("\n\t *** Cannot establish a connection with the database. ***");

        connection = reconnect(connection);
    }else {
        console.log("\n\t *** New connection established with the database. ***")
    }
});


//-
//- Reconnection function
//-
function reconnect(connection){
    console.log("\n New connection tentative...");

    //- Create a new one
    connection = mysql_npm.createPool(db_config);

    //- Try to reconnect
    connection.getConnection(function(err){
        if(err) {
            //- Try to connect every 2 seconds.
            setTimeout(reconnect(connection), 2000);
        }else {
            console.log("\n\t *** New connection established with the database. ***")
            return connection;
        }
    });
}


//-
//- Error listener
//-
connection.on('error', function(err) {

    //-
    //- The server close the connection.
    //-
    if(err.code === "PROTOCOL_CONNECTION_LOST"){    
        console.log("/!\\ Cannot establish a connection with the database. /!\\ ("+err.code+")");
        return reconnect(connection);
    }

    else if(err.code === "PROTOCOL_ENQUEUE_AFTER_QUIT"){
        console.log("/!\\ Cannot establish a connection with the database. /!\\ ("+err.code+")");
        return reconnect(connection);
    }

    else if(err.code === "PROTOCOL_ENQUEUE_AFTER_FATAL_ERROR"){
        console.log("/!\\ Cannot establish a connection with the database. /!\\ ("+err.code+")");
        return reconnect(connection);
    }

    else if(err.code === "PROTOCOL_ENQUEUE_HANDSHAKE_TWICE"){
        console.log("/!\\ Cannot establish a connection with the database. /!\\ ("+err.code+")");
    }

    else{
        console.log("/!\\ Cannot establish a connection with the database. /!\\ ("+err.code+")");
        return reconnect(connection);
    }

});


//-
//- Export
//-
module.exports = connection;