Creating a Distroless Node.js 18 Container Image¶

About This Task¶

With an eLxr Server 12 development host, you can either obtain the source or create your own to build a distroless container image that runs a Node.js application as described in this procedure.

When planning your container image, certain frameworks such as Spring Boot, Quarkus, and Micronaut, prefer a build that produces a single runnable JAR, or an exploded application layout, over copying the artifact into the distroless image. This procedure provides such an example.

Before You Begin¶

You must have a development host with Docker installed.
You must have the Node.js Development Kit installed, with npm (Node.js Package Manager).

Procedure¶

Create a directory for the container project and navigate to it.
```
$ mkdir -p my-distroless-app && cd my-distroless-app
```

Create a app.js file.

This is for example purposes. For your own container application, substitute this code with you own.

const http = require('http');
const port = process.env.PORT || 8080;

const server = http.createServer((req, res) => {
  res.end('Hello from Node.js Distroless!');
});

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

Create a package.json file.
```
{
    "name": "distroless-example",
    "version": "1.0.0",
    "main": "app.js",
    "dependencies": {}
}
```
This example uses the lightweight bundled com.sun.net.httpserver.HttpServer available in the JDK, which keeps the application dependency-free.

Create a multi-stage Dockerfile and name it nodejs-distroless-example.Dockerfile.

This Dockerfile uses a build stage to install dependencies and a production stage that copies only the necessary files to the distroless container image.

Dockerfile
# Build stage
FROM node:18-slim AS build
WORKDIR /app
COPY package*.json ./
RUN npm install --production
COPY . .

# Production stage (distroless Node.js)
FROM elxrlinux/elxr:latest-distroless-nodejs18
WORKDIR /app
COPY --from=build /app /app
CMD ["app.js"]

Build the Docker image.

$ docker build -t nodejs-distroless-example .

Run the container.

$ docker run -p 8080:8080 nodejs-distroless-example .

Visit http://localhost:8080 to see the application respond.
```
Hello from Node.js Distroless!
```

Results¶

Now that you have completed the distroless Node.js container image, consider learning about creating distroless Java images. For details, see Creating a Distroless Java 17 Container Image.