Development
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Kubernetes Node Affinity and EBS Volumes
Occasionally, Kubernetes workloads require specialized nodes. Sometimes it’s for machine learning, or to save money through burstable node types, or maybe just to lock certain Pods to a dedicated subset of nodes. Thankfully, Kubernetes offers a few useful mechanisms to inform the scheduler how we’d…
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RSpec Testing for Ruby AWS Lambda Functions
Recently, I wrote an AWS Lambda function at work in Ruby but I didn’t have a handy tool for creating a project skeleton like bundle gem does. That means nothing bootstrapped my testing for me. While copy+pasting code into pry proved that my simple function…
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Meet Bullion, An ACMEv2 Certificate Authority
I’m a huge fan of Let’s Encrypt and what they’ve done to secure the Internet. They’ve made safe communication free and open. Through their ACME protocol (and subsequent ACMEv2 protocol), they have changed PKI and the way we look at automating certificate provisioning for good.…
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Connected: A Ruby Graph Search Library
A common problem posed in coding competitions and undergraduate computer science classes is implementing an algorithm for finding the shortest path through a series of interconnected nodes. It can be phrased in many ways, mostly because graph theory (which is the domain of this particular…
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Rewriting Ruby’s #pack and #unpack Methods in Crystal
In Ruby, especially while writing low-level protocols, you may have encountered Array#pack() and/or String#unpack(). If you’ve ever experimented with them, they may seem mysterious; they take a cryptic string as a parameter (maybe something like C4 or w*) and seem to return gibberish (or, conversely,…
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Redis, Ruby, and Some Surprising Uses
Any developer worth their salt knows that Redis is great for caching. As an in-memory cache, it gets the job done. You certainly don’t have to take my word for it; the major sponsors of Redis (redislabs) wrote a white paper to explain it. What…
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Skull Island: A CLI and SDK for Kong
I’ve been working on an open-source project for managing the Kong API Gateway, both as an SDK and as a CLI tool using a straightforward, YAML-based templated configuration. The project is called Skull Island and is available on RubyGems via skull_island, on DockerHub via jgnagy/skull_island,…
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Updating GoDaddy DNS Entries with Ruby
I bought a new (arguably better) domain for my blog now! If you’re reading this, you’ve probably noticed, but it is therubyist.org, because I’m a fan of Ruby. The old name won’t be going anywhere, at least for the time being. Given the purchase of…
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Read-only Docker Containers
There are lots of good reasons for and articles recommending running Docker containers read-only, but what I have a difficult time finding are descriptions of how to do this for many popular images. Some software needs to write to a few important and predictable locations.…
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Distributing CLI Tools via Docker
Throughout my career, I’ve seen a couple recurring patterns related to the tools I write: I write a lot of small CLI tools and I like to share them with my coworkers (and whenever possible, the rest of the world). This has led to several…