Tutorial: Dockerize a Node.js Express app with a Redis database

1. Make sure the JavaScript Debugger, Node.js, Node.js Remote Interpreter, and Docker required plugins are enabled on the Settings | Plugins page, tab Installed. For more information, refer to Managing plugins.

2. Download, install, and configure Docker as described in Docker.

1. Click New Project on the Welcome screen or select File | New | Project from the main menu.

2. In the dialog that opens, select Node.js in the left-hand pane.

3. Specify the location of the application and its name, for example, counter.

4. Specify the local Node.js runtime to use. Accept the suggested installation or select another one from the list, or even click Download if you do not have Node.js on your machine yet. Learn more from Create a new Node.js application.

   

5. Click Create.

1. Open the Project tool window Alt+1, right-click the project folder, select New from the context menu, and then select JavaScript File.

   

2. In the popup dialog that appears, specify the name of the file, for example, index.js.

   

   WebStorm creates a file index.js and opens it in the editor.

3. In the index.js file, enter the following code:

   const express = require('express'); const redis = require('redis'); const app = express(); // The host name 'redis-server' will be specified in docker-compose.yml const client = redis.createClient({ url: 'redis://redis-server:6379' }); client.on('error', (err) => console.log('Redis Client Error', err)); app.get('/', async (req, res) => { try { // The `incr` command atomically increments the value stored at the key by 1. // If the key does not exist, it is created with the value 0 before the increment. const visits = await client.incr('visits'); res.send(`The number of visits is ${visits}`); } catch (err) { res.status(500).send('Error while accessing Redis'); } }); // First we connect to Redis, and then we run the server app.listen(3000, async () => { await client.connect(); console.log('Server running at port 3000'); });

4. WebStorm detects that the Express framework and the client to work with Redis are missing and highlights the references to them as unresolved.

   Place the cursor at an unresolved reference, press Alt+Enter, and then select Install 'express' as dev dependency or Install 'redis' as dev dependency.

   

Create a Dockerfile

1. From the context menu of the project folder, select New, and then select Dockerfile.

   

2. Open the newly created Dockerfile and type the following code:

   # Specify a light-weight Node.js image FROM node:22-alpine # Specify the working directory inside the container WORKDIR /usr/src/app COPY package*.json ./ RUN npm install --production COPY . . # Expose the container's port EXPOSE 3000 # Specify the command to launch application CMD ["node", "index.js"]

Create a docker-compose.yml file

1. From the context menu of the project folder, select New and then select Docker Compose File.

   

   In the popup that opens, accept the default Docker Compose file name or specify a custom one and press Enter.

   

2. Open the newly created docker-compose.yml and type the following code:

   services: redis-server: image: redis:alpine web: # The build directive instructs Docker Compose to build # an image of our application based on the Dockerfile # from the current folder build: . # Bind the local port with port inside the container ports: - "3000:3000" # The depends_on directive ensures that # the container starts after the redis-server depends_on: - redis-server

• In the docker-compose.yml, click next to services and select Run on Docker from the context menu to run the docker compose up -d command.

  

Check whether the application works as expected

1. Open the browser at http://localhost:3000. The page opens showing The number of visits is 1.

2. Refresh the page several times to see that the counter increments.