Deploying Nodejs Express js App on heroku-CodePudding

I'm trying to deploy my app on heroku, but I'm always getting this error

2022-08-11T12:49:12.131468 00:00 app[web.1]: Error: connect ECONNREFUSED 127.0.0.1:3306
2022-08-11T12:49:12.131469 00:00 app[web.1]: at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1247:16) {
2022-08-11T12:49:12.131470 00:00 app[web.1]: errno: -111,
2022-08-11T12:49:12.131470 00:00 app[web.1]: code: 'ECONNREFUSED',
2022-08-11T12:49:12.131470 00:00 app[web.1]: syscall: 'connect',
2022-08-11T12:49:12.131471 00:00 app[web.1]: address: '127.0.0.1',
2022-08-11T12:49:12.131471 00:00 app[web.1]: port: 3306,
2022-08-11T12:49:12.131471 00:00 app[web.1]: fatal: true
2022-08-11T12:49:12.131472 00:00 app[web.1]: }
2022-08-11T12:49:12.131494 00:00 app[web.1]:
2022-08-11T12:49:12.131494 00:00 app[web.1]: Node.js v18.7.0

Could anybody help me solve this problem? This is the server.js

const express = require('express')
const app = express()

app.set('view engine', 'ejs')

const filterByDateRouter = require('./routes/filterByDate');
const filterByLogsRouter = require('./routes/filterByLogs');
const mainPageRouter = require('./routes/index'); 

app.use("/filterByDate", filterByDateRouter)
app.use("/filterByLogs", filterByLogsRouter)
app.use("/",mainPageRouter)
app.use(express.static(__dirname   '/public/css'))
app.use(express.static(__dirname   '/public/js'))


app.listen(process.env.PORT || 3000)

this is the database connection:

var connection = mysql.createPool({
  host: process.env.DB_HOST,
  user: process.env.DB_USER,
  password: process.env.DB_PASSWORD,
  connectionLimit:10,
  database: process.env.DB_NAME,
});

I'm using clearMYSQL from heroku to deploy my database, and all the fields saved in the .env are right

CodePudding user response：

You can read the CLEARDB_DATABASE_URL and parse it:

const url = new URL(process.env.CLEARDB_DATABASE_URL);
const host = url.hostname;
const port = url.port || 3306;
const user = url.username;
const password = url.password;
const database = url.pathname.substring(1);
const connection = mysql.createPool({
  host,
  user,
  password,
  connectionLimit:10,
  database,
  port
});

CodePudding user response：

You are trying to connect to 127.0.0.1, while heroku doesn't host the database on the same container. Looking at the heroku-documentation, you will need to get the host from the config, by doing:

heroku config | grep CLEARDB_DATABASE_URL

This will return you a mysql://-url, which you should add as a variable. This is also described in the documentations and achievable by doing:

heroku config:set DATABASE_URL='<result-of-first-command>'

More information is available here.

CodePudding user response：

You can also add your enviroment variables that are provided by hosting providers. You can also add env variables in heroku from settings>Config Vars

https://i.stack.imgur.com/Qacht.png