Docker

Docker is a platform for developing, shipping and running applications in isolated, lightweight and portable containers. It is a critical part of a developer’s toolbelt and one I use just about everyday. Docker can consume a large amount of disk space. Per the Docker documentation: Docker takes a conservative approach to cleaning up unused objects (often referred to as “garbage collection”), such as images, containers, volumes, and networks: these objects are generally not removed unless you explicitly ask Docker to do so. This can cause Docker to use extra disk space. ...

Misconfigured Docker containers can be slow, heavy and difficult to maintain. This leads to sluggish releases, high storage costs and frustrated developers. Moreover, inadequate Docker containers can be a major security liability. A recent report by Aqua Security found that 50% of new Docker instances are attacked within 56 minutes of being deployed. Docker problems can be devastating for any business and software teams need to put in the time and energy to alleviate these risks. ...

See the source code for a working example. Next.js is a popular React Framework that comes with a lot of great features such as hybrid static & server rendering, smart bundling, file system routing, and much more. I prefer it over vanilla React. When we dockerize a Next.js application, we want the final production and development images to be small, fast to build and easy to maintain. Let’s see how we can use multi-stage builds and other image optimization techniques to create the ideal images. ...

See the source code for a working example. UI testing is a critical part of any modern web application. My favorite testing framework is Cypress which enables you to write clean, fast and reliable tests. It consists of two main commands: cypress run: Runs Cypress tests from the CLI without a GUI. Used mostly in CI/CD. cypress open: Opens Cypress in an interactive GUI. Used for local development. I like to dockerize my entire application so it can be run anywhere (my machine, coworker’s machine, CI/CD, etc.) and Cypress is no exception. We’re going to dockerize the cypress run and cypress open commands for a simple Todo application written in Django and Next.js (check out the source code). ...

You can use watchman in your Django project to make auto-reloads more CPU efficient. Adam Johnson’s Efficient Reloading in Django’s Runserver With Watchman blog post does an excellent job describing how to set this up. I highly recommend giving it a read. The tutorial explains how to install watchman on macOS with brew install watchman but does not explain how to install it in a Python docker container. Considering all of my Django projects are dockerized, I decided to figure it out. ...