Stephanie Jerome SoftwareSage💻

How to Deploy a Node.js App Using Docker

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Jerome Stephanie
·

3 min read

Introduction

In today’s fast-paced tech world, developers prioritize deploying applications efficiently. Docker, a powerful containerization platform, has revolutionized how we build, ship, and run applications. With Docker, you can package your Node.js app with all its dependencies into a container, ensuring it works seamlessly across different environments. This tutorial will walk you through deploying a simple Node.js app using Docker.

Step 1: Install Docker and Set Up Your Environment

Before we begin, make sure Docker is installed on your system.

  1. Download Docker from the official website

  2. Follow the installation guide for your operating system.

  3. Verify the installation by running the following command in your terminal:

docker --version

If you see the Docker version displayed, you're ready to proceed.

Step 2: Write a Simple Node.js Application

Let’s create a basic Node.js application. Follow these steps:

  1. Create a new folder and navigate to it:
mkdir node-docker-app && cd node-docker-app
  1. Initialize a Node.js project and install Express:
npm init -y
npm install express
  1. Create an index.js file with the following content:
const express = require('express');
const app = express();
const PORT = 3000;

app.get('/', (req, res) => {
    res.send('Hello, Dockerized World!');
});

app.listen(PORT, () => {
    console.log(`App running on http://localhost:${PORT}`);
});
  1. Test your app locally by running:
node index.js

Open your browser and visit http://localhost:3000. You should see "Hello, Dockerized World!"

Step 3: Create a Dockerfile

A Dockerfile is a script defining how to build your application's Docker image. Create a file named Dockerfile in your project folder add the following:

# Use the official Node.js image as the base image
FROM node:16

# Set the working directory
WORKDIR /app

# Copy package.json and package-lock.json
COPY package*.json ./

# Install dependencies
RUN npm install

# Copy the rest of the application files
COPY . .

# Expose the port your app runs on
EXPOSE 3000

# Command to run the application
CMD ["node", "index.js"]

Step 4: Build and Run the Docker Image

Now, let’s containerize your Node.js app.

  1. Build the Docker image:
docker build -t node-docker-app .
  1. Run the Docker container:
docker run -p 3000:3000 node-docker-app
  1. Open your browser and visit http://localhost:3000 to see your app running inside a Docker container!

Step 5: Push the Image to Docker Hub and Deploy

To share your Docker image or deploy it to a server, you can push it to Docker Hub.

  1. Log in to Docker Hub:
docker login
  1. Tag your image:
docker tag node-docker-app your-dockerhub-username/node-docker-app
  1. Push the image:
docker push your-dockerhub-username/node-docker-app
  1. You can now pull and run this image on any server:
docker run -p 3000:3000 your-dockerhub-username/node-docker-app

Conclusion

Docker makes deploying applications consistent and efficient by packaging everything into a container. With just a few commands, you’ve created, containerized, and deployed a Node.js app. By leveraging Docker, you eliminate the classic "it works on my machine" problem, ensuring your app runs reliably across all environments. Start integrating Docker into your workflow and unlock a new level of productivity!

DockerNode.jsdeploymentTutorialWeb Development