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In my previous article, I explained how to use ftrace to trace kernel functions. Using ftrace by writing and reading from files can get tedious, so I used a wrapper around it to run commands with options to enable and disable tracing, set filters, view output, clear output, and more.

When I recently read Alan Formy-Duval's article Manage your Raspberry Pi with Cockpit, I thought it would be a good idea to have an image with Cockpit already preinstalled. Luckily there are at least two ways to accomplish this task: 

Pete Townshend, legendary guitar player for British rock band The Who, is well-known for playing suspended chords. Suspended chords add musical tension to a song. For those piano players reading this who (like me) love to play in the key of C, simply play a C major chord (the notes C, E, and G) and replace the E note with either an F or a D. You are now on your way to becoming a British rock star!1

No matter how much storage space you have, there's always the possibility for it to fill up. On most personal devices, drives get filled up with photos and videos and music, but on servers, it's not unusual for space to diminish due to data in user accounts and log files. Whether you're in charge of managing a multi-user system or just your own laptop, you can check in on disk usage with the du command.

By default, du provides the amount of disk space used in your current directory, as well as the size of each subdirectory:

An operating system's kernel is one of the most elusive pieces of software out there. It's always there running in the background from the time your system gets turned on. Every user achieves their computing work with the help of the kernel, yet they never interact with it directly. The interaction with the kernel occurs by making system calls or having those calls made on behalf of the user by various libraries or applications that they use daily.

The cron system is a method to automatically run commands on a schedule. A scheduled job is called a cronjob, and it’s created in a file called a crontab. It’s the easiest and oldest way for a computer user to automate their computer.

To create a cronjob, you edit your crontab using the -e option:

WildFly is a production-ready, cross-platform, flexible, lightweight, managed application runtime that provides all the necessary features to run a Java web application. It is also a Java EE 8 certified application server almost exclusively in Java, and it implements the Jakarta EE, which was the Java Platform, Enterprise Edition (Java EE) specifications. Therefore you can run it on any operating system.

A screen reader is a vital tool that helps individuals who are blind or low-vision read digital text. Unfortunately, not all file formats receive the same level of support from screen readers. For example, while PDF files have accessibility features that you can use, they are often not the preferred file format for screen reader users. Between line breaks, multiple columns, symbols, and images, screen readers can have trouble reading PDFs in a cohesive way to their users.

Did you get our summer reading list?

Kubernetes is software to help you run lots of containers in an organized way. Aside from providing tools to manage (or orchestrate) the containers you run, Kubernetes also helps those containers scale out as needed. With Kubernetes as your central control panel (or control plane), you need a way to manage Kubernetes, and the tool for that job is kubectl. The kubectl command lets you control, maintain, analyze, and troubleshoot Kubernetes clusters.

JavaScript is a programming language full of pleasant surprises. Many people first encounter JavaScript as a language for the web. There's a JavaScript engine in all the major browsers, there are popular frameworks such as JQuery, Cash, and Bootstrap to help make web design easier, and there are even programming environments written in JavaScript.

People who let open principles guide their leadership practices in open organizations inevitably find themselves fielding feedback. Lots of feedback.

That's by design. Open leaders invite comment and critique on just about anything they can.

But it also poses a regular challenge: How to sift through, manage, evaluate, and address that feedback in authentic and useful ways?

For a long time, attention deficit hyperactivity disorder (ADHD), autism, Asperger syndrome, dyslexia, and other neurodiverse conditions were considered things that hold people back. But now, many researchers and employers recognize that neurodiversity is a competitive advantage, especially in technology, and especially when certain accommodations are provided.

Web components are a collection of open source technologies such as JavaScript and HTML that allow you to create custom elements that you can use and reuse in web apps. The components you create are independent of the rest of your code, so they're easy to reuse across many projects.

Best of all, it's a platform standard supported by all major modern browsers.

Most computer users nowadays rely on online file storage. Thanks to the rise of cloud computing, the idea of storing files remotely and downloading them when needed has gained a lot of fresh air in recent years. Yet, the principle's technical roots are anything but new, with implementations reaching back decades. While the protocols used and features expected for accessing data on online storage have changed massively, the basic idea hasn't altered much since the days of FTP and similar protocols.

Fedora CoreOS is an automatically updating, minimal rpm-ostree-based operating system for running containerized workloads securely and at scale.

Podman "is a tool for managing containers and images, volumes mounted into those containers, and pods made from groups of containers. Podman is based on libpod, a library for container lifecycle management."

There are many ways to get applications onto a Linux system. Some, like Flatpak and containers, are new. Others, like DEB and RPM, are classic formats that have withstood the test of time.

If you use Python, you probably install a lot of Python applications. Some are tools you just want to try out. Others are tried and true applications you use every day, so you install them on every computer you use. In either situation, it can be useful to run your Python applications in virtual environments to keep them and their dependencies separate from one another to avoid versioning conflicts and to keep them from the rest of your system to improve security.

This is where pipx comes into the picture.

As the world turns and some folks begin returning to the office, I feel it's a good time to ask our community of open source techies: What's your work-from-home (WFH) uniform?

Do you dress like you would if you were going into the office? Or are you more comfortable in workout clothes or even your PJs? Do you have a template you stick to most days?

The long road toward quality is filled with diversions, false starts, and detours. The enemy of quality is waste, because waste is never desirable. No one pays anyone to deliver waste. We sometimes tolerate waste as part of the process of making something useful and desirable, but the more we can reduce waste while making something, the better.

In software engineering, waste can be expressed in a few ways: