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In this article I’ll share some observations, tips and tricks for the Linux Foundation’s “Certified Kubernetes Administrator certification and exam. I’ve been operating Kubernetes in multiple environments for a few years now. I thought this would be an easy certification to get, but I was surprised by how hard it was! I took this exam without doing any formal training, I mostly focused on the areas of the curriculum which I knew I was a little weak at.

In this article I’ll demonstrate how to use Golang to manipulate Kubernetes Custom Resources, with Istio as an example. No knowledge of Istio is needed, I’ll just use it to demonstrate the concepts! Istio is a highly popular Service Mesh platform which allows engineers to quickly add telemetry, advanced traffic management and more to their service-based applications. One interesting element of how Istio works is that when deployed into a Kubernetes cluster, many key configuration objects are handled as Custom Resources.

Recently I needed to be able to quickly adjust the number of replicas in a Kubernetes Replication Controller. The original solution I’d seen pulled down the spec, modified it, then updated it. There’s a better way! There’s a patch API for Kubernetes resources. Patching resources is faster and easier than pulling them and updating the spec wholesale. However, the documentation is a little limited. After some trial and error I got it working, here’s the solution.

En Español | Reddit Thread | Hacker News Thread Microservices became a very popular topic over the last couple of years1. ‘Microservice madness’ goes something like this: Netflix are great at devops. Netflix do microservices. Therefore: If I do microservices, I am great at devops. There are many cases where great efforts have been made to adopt microservice patterns without necessarily understanding how the costs and benefits will apply to the specifics of the problem at hand.

In this article I’m going to show you how to set up OpenShift to integrate with Splunk for logging in a Docker container orchestration environment. These techniques could easily be adapted for a standard Kubernetes installation as well! The techniques used in this article are based on the Kubernetes Logging Cluster Administration Guide. I also found Jason Poon’s article Kubernetes Logging with Splunk very helpful. First, clone the Terraform AWS OpenShift repo: