Free up disk space with Docker prune

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....

January 21, 2023 · 4 min · Johnny Metz

[Cross-Post] Enforce Best Dockerfile Practices with Hadolint

See the post here: Using Hadolint, a Dockerfile linter, To Enforce Best Practices

March 17, 2022 · 1 min · Johnny Metz

Dockerize a Next.js app using multi-stage builds

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....

February 26, 2022 · 4 min · Johnny Metz

Dockerize your Cypress tests

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....

January 31, 2022 · 5 min · Johnny Metz

Free up Django CPU usage in Docker with Watchman

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....

January 4, 2022 · 2 min · Johnny Metz