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image from Validating HTTP(S) URLs in Ruby on Rails

Validating HTTP(S) URLs in Ruby on Rails

Regular expressions are not a great way to validate URLs. Using Ruby’s built-in URI parser, a custom Active Record Validation Helper can be built to safely validate URLs in Ruby on Rails applications while allowing for flexible domain name allow-listing.
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image from The broken windows of software

The broken windows of software

In sociology, the broken windows theory states that if a window in a building is broken and is left unrepaired, all the rest of the windows will soon be broken. This equally applies to software developement is it’s importatnt to be aware of this and make fixing these broken windows a team priority!
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image from Trix editor as a Blazor Component

Trix editor as a Blazor Component

Trix is a rich text editor that is popular with Ruby on Rails developers. In this post we’re going to take Trix out of Rails and use it inside an ASP.NET Blazor application by making a drop in replacement for Blazor’s InputText component.
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image from Deploying AWS CloudFormation templates from CircleCI

Deploying AWS CloudFormation templates from CircleCI

CircleCI provides several official orbs for interacting with Amazon Web Services, but not for CloudFormation specifically. However, that doesn’t mean you need to reach for a community orb to update your stacks from a CI pipeline. A single AWS CLI command is all that is needed to push template updates to your AWS account.
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image from Pair a TRÅDFRI remote to deCONZ - the hard way

Pair a TRÅDFRI remote to deCONZ - the hard way

Years ago I replaced my IKEA TRÅDFRI gateway with a Rasbperry Pi with a Raspbee, running deCONZ. It allowed me to mix and match ZigBee devices from various brands and make flexible configurations. Plus the integration with Home Assistant is superb. However, one thing I lost is the ability for the IKEA remote to control my lights directly when the deCONZ gateway is down, which was possible back when I used the IKEA gateway.
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image from It's time to consider C# and .NET 5

It's time to consider C# and .NET 5

People have been sleeping on .NET and they’re mising out. With the release of .NET 5 this month, it’s time to consider C# .NET for your next project! It’s a great general-purpose software framework that’s likeable, in high demand, easy to sell to customers, has decent performance, is completely open source, mature and has a large backing. What more could you want? Let me explain to you why I see it as the best alternative for Ruby on Rails and share some resources to get you started.
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image from Full resolution Jump Desktop on iPad Pro 11" using SwitchResX

Full resolution Jump Desktop on iPad Pro 11" using SwitchResX

Since the introduction of the Magic Keyboard, interest in using an iPad as a remote terminal for desktops is bigger than ever. The tool of choice for many iPad enthusiasts seems to be Jump Desktop, which supports VNC, RDP and their proprietary Fluid protocol. Let’s try to get the most out of it when connecting to a macOS desktop.
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Adding external hosts to a Prometheus Operator helm release

Prometheus Operator is the perfect cloud-native monitoring solution for Kubernetes. By deploying the Helm chart you get a preconfigured Prometheus and Grafana setup plus an array of CRDs to add monitoring your own services. Not everything necessarily lives in a Kubernetes cluster, though. So how would you add external targets to a Prometheus Operator setup? One could define an Endpoint, Service and ServiceMonitor for the external resource to have it picked up by Prometheus' Kubernetes service discovery, which works, but there is a better solution that is more in line with how Prometheus is used outside of the Operator deployment.
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Efficient XML parsing in Ruby

TL;DR I wrote a super fast Excel file reader called Xsv, check it out! It’s fast and low on memory because it uses a SAX-based XML parser instead of a DOM-based one. Here’s some benchmarks to prove it. Simple API for XML, or SAX for short is an event-based API, of which development started in December 1997 1. It is an alternative to the well-known Document Object Model, which was developed around the same time 2.
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Add jemalloc to your Ruby Docker images, now!

The topic of this post is neither new nor original, so I’m going to keep things short. People have been using jemalloc with MRI Ruby for years and praising it’s benefits all the while. The TL;DR here is: for Rails apps, using jemalloc will reduce memory consumption and might increase performance a little. Why? To illustrate my own experience, here’s a Grafana graph showing the effect of switching to jemalloc on a production server running a few instances of a Rails application:
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Disable JavaScript source maps in production Rails applications

Ruby on Rails 6 allows us to leverage the excellent Webpack bundler to manage JavaScript and CSS components in a way that’s more native to those technologies than the old asset pipeline: no more gems to wrap JavaScript libraries and no more libv8 gem issues. Another advantage Webpack brings is the excellent source maps. I was surprised to see the source code of my Svelte components, complete with comments available from the Firefox development tools:
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image from PICO-8 is the coolest thing I've seen all year

PICO-8 is the coolest thing I've seen all year

For a long time I’ve been thinking about getting out of my comfort zone and try to develop a game for something like the Sega Mega Drive or maybe the Atari 2600. But for a spoiled high-level developer like me that would be quite a daunting task so I’ve postponed indefinitely. Then last week, in the midst of the COVID-19 crisis, I stumbeld upon this awesome project called PICO-8. To quote the official website:
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