balenalib/qemux86-alpine-node

This image is part of the balena.io base image series for IoT devices. The image is optimized for use with balena.io and balenaOS, but can be used in any Docker environment running on the appropriate architecture.

!balenalogo.

Some notable features in balenalib base images:

• Helpful package installer script called install_packages that abstracts away the specifics of the underlying package managers. It will install the named packages with smallest number of dependencies (ignore optional dependencies), clean up the package manager medata and retry if package install fails.

• Working with dynamically plugged devices: each balenalib base image has a default ENTRYPOINT which is defined as ENTRYPOINT ["/usr/bin/entry.sh"], it checks if the UDEV flag is set to true or not (by adding ENV UDEV=1) and if true, it will start udevd daemon and the relevant device nodes in the container /dev will appear.

For more details, please check the features overview in our documentation.

Image Variants

The balenalib images come in many flavors, each designed for a specific use case.

:<version> or :<version>-run

This is the defacto image. The run variant is designed to be a slim and minimal variant with only runtime essentials packaged into it.

:<version>-build

The build variant is a heavier image that includes many of the tools required for building from source. This reduces the number of packages that you will need to manually install in your Dockerfile, thus reducing the overall size of all images on your system.

How to use this image with Balena

This guide can help you get started with using this base image with balena, there are also some cool example projects that will give you an idea what can be done with balena.

What is Node.js?

Node.js is a software platform for scalable server-side and networking applications. Node.js applications are written in JavaScript and can be run within the Node.js runtime on Mac OS X, Windows, and Linux without changes.

Node.js applications are designed to maximize throughput and efficiency, using non-blocking I/O and asynchronous events. Node.js applications run single-threaded, although Node.js uses multiple threads for file and network events. Node.js is commonly used for real-time applications due to its asynchronous nature.

Node.js internally uses the Google V8 JavaScript engine to execute code; a large percentage of the basic modules are written in JavaScript. Node.js contains a built-in, asynchronous I/O library for file, socket, and HTTP communication. The HTTP and socket support allows Node.js to act as a web server without additional software such as Apache.

***.org/wiki/Node.js

!https://raw.githubusercontent.com/docker-library/docs/01c***b2fe592c1f93a13b4e289ada0e3a1/node/logo.png.

Supported versions and respective Dockerfile links :

https://github.com/balena-io-library/base-images/tree/master/balena-base-images/node/qemux86/alpine/

For more information about this image and its history, please see the https://github.com/balena-io-library/official-images/blob/master/library/qemux86-alpine-node in the https://github.com/balena-io-library/official-images.

How to use this image

Create a Dockerfile in your Node.js app project

dockerfile
# specify the node base image with your desired version node:<version>
FROM balenalib/qemux86-alpine-node:latest
# replace this with your application's default port
EXPOSE 8888

You can then build and run the Docker image:

console
$ docker build -t my-nodejs-app .
$ docker run -it --rm --name my-running-app my-nodejs-app

If you prefer Docker Compose:

yml
version: "2"
services:
  node:
    image: "balenalib/qemux86-alpine-node:latest"
    user: "node"
    working_dir: /home/node/app
    environment:
      - NODE_ENV=production
    volumes:
      - ./:/home/node/app
    expose:
      - "8081"
    command: "npm start"

You can then run using Docker Compose:

console
$ docker-compose up -d

Docker Compose example copies your current directory (including node_modules) to the container. It assumes that your application has a file named package.json defining start script.

Run a single Node.js script

For many simple, single file projects, you may find it inconvenient to write a complete Dockerfile. In such cases, you can run a Node.js script by using the Node.js Docker image directly:

console
$ docker run -it --rm --name my-running-script -v "$PWD":/usr/src/app -w /usr/src/app balenalib/qemux86-alpine-node:latest node your-daemon-or-script.js

User Feedback

Issues

If you have any problems with or questions about this image, please contact us through a https://github.com/balena-io-library/base-images/issues.

Contributing

You are invited to contribute new features, fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.

Before you start to code, we recommend discussing your plans through a https://github.com/balena-io-library/base-images/issues, especially for more ambitious contributions. This gives other contributors a chance to point you in the right direction, give you feedback on your design, and help you find out if someone else is working on the same thing.

Documentation

Documentation for this image is stored in the base images documentation. Check it out for list of all of our base images including many specialised ones for e.g. node, python, go, smaller images, etc.

You can also find more details about new features in balenalib base images in this blog post