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Run Express Locally for Elastic Beanstalk

Prerequisites

  • Node.js 18 or later installed.
  • A terminal in your project folder.
  • npm registry access for installing dependencies.
  • Basic familiarity with JavaScript modules and Express.

What You'll Build

You will create a minimal Express app that listens on process.env.PORT with a default of 8080, define a start command, and declare a Node engine version in package.json so the app aligns with Elastic Beanstalk Node.js expectations.

flowchart TD
    A[npm start] --> B[Node.js process]
    B --> C[Express app]
    C --> D[listen on process.env.PORT or 8080]
    D --> E[Local browser request]

Steps

  1. Initialize a new npm project and install Express.

    npm init --yes
npm install express

  2. Create app.js with an Elastic Beanstalk-compatible port pattern.

    const express = require("express");

const app = express();
const port = process.env.PORT || 8080;

app.get("/", (req, res) => {
    res.send("Hello from Elastic Beanstalk Node.js");
});

app.listen(port, () => {
    console.log(`Server listening on ${port}`);
});

  3. Update package.json scripts and engine constraints.

    {
    "name": "eb-nodejs-app",
    "version": "1.0.0",
    "private": true,
    "main": "app.js",
    "scripts": {
        "start": "node app.js"
    },
    "engines": {
        "node": ">=18"
    },
    "dependencies": {
        "express": "^4.19.2"
    }
}

  4. Run the application locally.

    npm start

  5. Test with a local request.

    curl --verbose http://127.0.0.1:8080/

Verification

  • Terminal shows Server listening on 8080 or another value from PORT.
  • HTTP request returns a 200 response and the example message body.
  • package.json contains both scripts.start and engines.node.
  • Source tree is ready for Elastic Beanstalk source bundle packaging.

See Also

Sources