Unable to connect to Heroku's database using sequelize-typescript

Question

My Express API using sequelize-typescript cannot connect to Heroku's PostgreSQL database.

The Heroku app was initialized by running the following commands:

heroku create <my-app-name>
heroku addons:create heroku-postgresql:hobby-dev
git push heroku master

This application runs without problems in my local environment.

I can confirm that the DATABASE_URL environment variable is correct on Heroku.

My package.json scripts also seem to be correct:

"scripts": {
  "build": "tsc",
  "dev": "node_modules/.bin/nodemon",
  "postinstall": "npm run build",
  "start": "node dist/server/server.js"
}

---

What I've tried to solve the problem from most important to least:

1. Setting NPM_CONFIG_PRODUCTION=false by doing heroku config:set. I did this after reading through this SO thread, which pointed to this Heroku document. I think the idea is that this tells Heroku to skip the step where it prunes the devDependencies so Heroku can compile the TypeScript files into Javascript.

2. Setting dialectOptions: { ssl: true } in my Sequelize connection when process.env.NODE_ENV === 'production'. I did this after reading a couple of SO documents on this topic.

3. Providing the Sequelize connection with the username and password fields. I did this by doing:

// In the terminal
heroku config:set DB_USER=<database user from Heroku database credentials>
heroku config:set DB_PASSWORD=<database password from Heroku database credentials>

// In Sequelize connection
export const connection = new Sequelize({
    dialect: 'postgres',
    protocol: 'postgres',
    username: process.env.DB_USER || '',
    password: process.env.DB_PASSWORD || '',
    database: process.env.DATABASE_URL || 'fitnius-db',
    logging: false,
    dialectOptions: { ssl },
    models: [__dirname + '/models', __dirname + '/models' + '/joins']
})

4. Adding @types/pg as a dependency

5. Deleting my Heroku app and instantiating a new one

6. Removing "node_modules" from "exclude": [] in tsconfig.json

7. Removing all environment variables from nodemon.json

8. Creating a Procfile and adding web: node dist/server/server.js inside of it

9. Moving, @types/express and @types/sequelize around between dependencies and devDependencies. I was desperate and read through this document from Sequelize.

   • Also, installing @types/node and @types/validator as dependencies

10. Setting build script to "build": "tsc -p ." (Not exactly sure what the -p flag does... but I did it)

11. Setting a relative path to the compiled server file in my start script:

    • "start": "node ./dist/server/server.js"

Question: How can I get Sequelize to establish a connection to Heroku's PostgreSQL database and get my application running?

Below is relevant code pertaining to the issue.

---

Error log from heroku logs --tail

{ SequelizeConnectionRefusedError: connect ECONNREFUSED 127.0.0.1:5432
at connection.connect.err (/app/node_modules/sequelize/lib/dialects/postgres/connection-manager.js:170:24)
at Connection.connectingErrorHandler (/app/node_modules/pg/lib/client.js:191:14)
at Connection.emit (events.js:198:13)
at Socket.reportStreamError (/app/node_modules/pg/lib/connection.js:72:10)
at Socket.emit (events.js:198:13)
at emitErrorNT (internal/streams/destroy.js:91:8)
at emitErrorAndCloseNT (internal/streams/destroy.js:59:3)
at process._tickCallback (internal/process/next_tick.js:63:19)
name: 'SequelizeConnectionRefusedError',
parent:
{ Error: connect ECONNREFUSED 127.0.0.1:5432
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1106:14)
errno: 'ECONNREFUSED',
code: 'ECONNREFUSED',
syscall: 'connect',
address: '127.0.0.1',
port: 5432 },

at=error code=H10 desc="App crashed" method=GET path="/" 
host=fitnius-web-api.herokuapp.com 
request_id=c8c76ce3-8201-4733-99fb-bee4121b09d1 fwd="100.1.44.6" 
dyno= connect= service= status=503 bytes= protocol=https

Sequelize connection

import { Sequelize } from 'sequelize-typescript'

const ssl = process.env.NODE_ENV === 'production'

export const connection = new Sequelize({
    dialect: 'postgres',
    protocol: 'postgres',
    database: process.env.DATABASE_URL || 'fitnius-db',
    logging: false,
    dialectOptions: { ssl },
    models: [__dirname + '/models', __dirname + '/models' + '/joins']
})

Express server

import app from './app'
import { connection } from '../database/connection'

const PORT = process.env.PORT || 3000
connection
    .sync()
    .then(() => {
        app.listen(PORT, () => console.log(`Server is running on port ${PORT}`))
    })
    .catch(err => console.log(err))

tsconfig.json

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs",
    "outDir": "dist",
    "strict": true,
    "declaration": true,
    "esModuleInterop": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "sourceMap": true,
    "lib": ["es6", "dom"]
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", ".vscode"]
}

package.json

{
  "name": "fitnius-server",
  "version": "1.0.0",
  "description": "",
  "main": "dist/server/server.js",
  "scripts": {
    "build": "tsc",
    "dev": "node_modules/.bin/nodemon",
    "postinstall": "npm run build",
    "start": "node dist/server/server.js"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@types/express": "^4.17.0",
    "@types/graphql": "^14.2.3",
    "@types/pg": "^7.4.14",
    "@types/sequelize": "^4.28.4",
    "express": "^4.17.1",
    "express-graphql": "^0.9.0",
    "graphql": "^14.4.2",
    "pg": "^7.12.0",
    "reflect-metadata": "^0.1.13",
    "sequelize": "^5.12.3",
    "sequelize-typescript": "^1.0.0-beta.3"
  },
  "devDependencies": {
    "nodemon": "^1.19.1",
    "ts-node": "^8.3.0",
    "typescript": "^3.5.3"
  }
}

Directory tree

root
  dist (compiled by tsc)
  node_modules
  src
    database
      models
      connection.ts (Sequelize connection)
    server
      app.ts
      server.ts (Express server)
  nodemon.json
  tsconfig.json
  package.json

Answer 1

After digging through sequelize-typescript's npm package, I found out the database parameter does not refer to the entire database's url.

I was able to solve the problem by parsing the following from Heroku's database url. I used this database url parser as my solution.

interface ParsedDatabaseOptions {
    protocol: string | undefined
    host: string | undefined
    username: string | undefined
    password: string | undefined
    database: string | undefined
}

After converting the parser into a rough TypeScript version, which can be found here, I then created a conditional by checking if NODE_ENV === 'production' and set my database options to either:

import { Sequelize } from 'sequelize-typescript'
// parseDatabaseUrl is currently a wonky piece of code
import parseDatabaseUrl from '../utils/parse-database-url'

const optionsProduction = parseDatabaseUrl(process.env.DATABASE_URL)
const optionsDevelopment = { database: <your local database> }

// Create conditional Sequelize database options here
const sequelizeOptions = process.env.NODE_ENV === 'production'
    ? optionsProduction
    : optionsDevelopment

const connection = new Sequelize({
    dialect: 'postgres',
    logging: false,
    ...sequelizeOptions, // Spread options here
    models: ...
})

Answer 2

1. Go to heroku's dashboard.
2. Go to your apps resources tab
3. Click on the database link
4. It'll take you to database's overview
5. Go to settings tab of database
6. Click on view credentials to view the db connection credentials