3 building

Building

Table of Contents

1. Goal

2. Steps

3. Best Practices

   3.1. General

   3.2. Python App

   3.3. NodeJS App

1. Goal

• Produce artifacts (e.g., executable, application image, software package, zipped source code, etc.) and version them.
• In this context, artifact is the docker image of the web application created from the corresponding Dockerfile for both apps.

2. Steps

• Write a Dockerfile in the root directory for each project

  • app_python/Dockerfile
  • app_nodejs/Dockerfile

• Add build and release instructions to the README.

3. Best Practices

3.1. General

• Use a Dockerfile linter (e.g., hadolint) as it helps build best practice Docker images.
• Use a small base image that does the job (e.g., alpine-based images) as it will make deployment faster while not taking much space.
• Copy only the necessary files to the image to make it smaller and faster, use .dockerignore to ignore unnecessary files and directories.
• Use EXPOSE documentation to make port-forwarding easier for other programmers reading your Dockerfile.
• Push the image to a container registry like DockerHub or the cloud-dedicated container registry for version control of app images and convenient deployment to the cloud.
• Tag the images with it’s version or the corresponding commit id from git to easily understand which version of the code is currently in the registry.

3.2. Python App

• Set environment variable PYTHONUNBUFFERED to a non-zero value to see container output from host in real-time.
• Use --no-cache-dir flag with pip install to prevent caching downloaded packages and make image size smaller.

3.3. NodeJS App

• Set environment variable NODE_ENV to production to configure ExpressJS with production settings.
• Use npm ci instead of npm install (see why).