One common question I see on Mastodon and Reddit is "I've inherited a cluster, how do I safely upgrade it". It's surprising that this still isn't a better understood process given the widespread adoption of k8s, but I've had to take over legacy clusters a few times and figured I would write up some of the tips and tricks I've found over the years to make the process easier.

Kubernetes is a superior platform for deploying and managing applications, but sometimes simple tasks like having the same data — in our case Secrets — between namespaces can cause slight problems and you have to build your own solutions to those problems.

TL;DR: In this article, you will learn tips and gotchas for writing YAML manifests for Kubernetes resources.

It seems like everywhere I look on the internet these days, somebody’s making some form of the following argument:

You don’t need distributed systems! Computers are so fast these days you can serve all your customers off a single machine!

This argument is silly and reductive.

But first, let’s look for the kernel of truth.

One Machine Is All You Need?

eks-node-viewer is a tool for visualizing dynamic node usage within a cluster. It was originally developed as an internal tool at AWS for demonstrating consolidation with Karpenter. It displays the scheduled pod resource requests vs the allocatable capacity on the node. It does not look at the actual pod resource usage.

A roadmap to learn Kubernetes from scratch (Beginner to Advanced level)

Demystifying the public status process.

A lightweight message queue. Like AWS SQS and RSMQ but on Postgres.

GitSwitch, the ultimate solution for managing multiple Git users across different vendors

Exploring how to do anomaly alerting on seasonal data in Prometheus.

Overmind is a powerful tool for real-time impact analysis on Terraform changes. Overmind can identify the blast radius and uncover potential risks with overmind terrafrom plan before they harm your infrastructure, allowing anyone to make changes with confidence. We also track the impacts of the changes you make with overmind teraform apply, so that you can be sure that your changes haven't had any unexpected downstream impact.

Open source data anonymization and synthetic data orchestration for developers. Create high fidelity synthetic data and sync it across your environments.