Error: connect ECONNREFUSED 127.0.0.1:3306 as AWS EC2 with nodes

Hi. I have Error and… I look around all of web site. but all of solution didn’t work. My setting is below information.

1. AWS : EC2(linux), route53, load balancer
2. nodJs with express
3. express listen port : 80
4. mysql : port 3306 (also, in EC2 security group, I’m authorize RDS server using RDS endpoint).

in my case, a little odd…

because of connecting domain, I should use port 80 in my EC2. but problem is if I set the port 80, then the linux block.

so, I use ‘sudo’, and then it’s work! but, the mysql to call the function give to me error like that Error: connect ECONNREFUSED 127.0.0.1:3306

if I change the express listen port to 3000 then mysql is good work! but another way, If I set the port at express as 3000 and use keyword ‘sudo’, then It will be same error

So, I think problem is related to use keyword ‘sudo’

do you know what happen???

I attach my source code… than you

const app = express();
const port = 3000;
app.use('/', express.static(__dirname + '/../public'));

app.post('/Master', (req, res) => {

    var name = req.body.name;
    var pwd = req.body.pwd;

    db.getMasterid(function(err, results){
        if(err) {
            res.send(500, "Server get  Error from Masterid");
            return;
        }
        

var pool = db.createPool({
    connectionLimit : 10,
    host            : process.env.MYSQL_HOST,
    user            : process.env.MYSQL_USER,
    password        : process.env.MYSQL_SECRET,
    database        : process.env.MYSQL_DB,
    port            : '3306',
    ssl             : "Amazon RDS",
})


exports.getMasterid = function(callback){
    var sql = 'select * from masterid';
    pool.getConnection((err, connection) => {
        if(err){
            console.log(err);
            callback(true);
            return;
        }
        connection.query(sql, (err, results, field) => {
            connection.release();
            if(err){
                console.log(err);
                callback(true);
                return;
            }
            callback(false, results);
        });
    });
};

Error Message

{ Error: connect ECONNREFUSED 127.0.0.1:3306
    at Object.exports._errnoException (util.js:1026:11)
    at exports._exceptionWithHostPort (util.js:1049:20)
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1081:14)
    --------------------
    at Protocol._enqueue (/home/ec2-user/mjlens/node_modules/mysql/lib/protocol/Protocol.js:141:48)
    at Protocol.handshake (/home/ec2-user/mjlens/node_modules/mysql/lib/protocol/Protocol.js:52:41)
    at PoolConnection.connect (/home/ec2-user/mjlens/node_modules/mysql/lib/Connection.js:130:18)
    at Pool.getConnection (/home/ec2-user/mjlens/node_modules/mysql/lib/Pool.js:48:16)
    at Object.exports.getMasterid (/home/ec2-user/mjlens/build/mysql_db/reservation_db.js:23:10)
    at /home/ec2-user/mjlens/build/main.js:111:30
    at Layer.handle [as handle_request] (/home/ec2-user/mjlens/node_modules/express/lib/router/layer.js:95:5)
    at next (/home/ec2-user/mjlens/node_modules/express/lib/router/route.js:137:13)
    at Route.dispatch (/home/ec2-user/mjlens/node_modules/express/lib/router/route.js:112:3)
    at Layer.handle [as handle_request] (/home/ec2-user/mjlens/node_modules/express/lib/router/layer.js:95:5)
  code: 'ECONNREFUSED',
  errno: 'ECONNREFUSED',
  syscall: 'connect',
  address: '127.0.0.1',
  port: 3306,
  fatal: true }

[sidorares]

console.log({
    host            : process.env.MYSQL_HOST,
    user            : process.env.MYSQL_USER,
    password        : process.env.MYSQL_SECRET,
    database        : process.env.MYSQL_DB
 })

[XOneto9]

@sidorares Thank you!!!