kubernetes

Quick 'Hello World' HTTP deployment for testing K3s and Traefik

Recently I needed to test the full HTTP stack between a Kubernetes cluster's member nodes and an external Internet routing setup, and so I wanted to quickly install K3s (which includes Traefik by default, and load balances through ports 80 and 443 on all nodes), then get a quick 'hello world' web page up, so I could see if the traffic was routing properly all the way from the external host through to a running container exposed via Traefik Ingress.

Here's how I set up a basic 'Hello World' web page on my K3s cluster:

First, I created an HTML file to be stored as a ConfigMap. Create a file named index.html with the following contents:

<html>
<head>
  <title>Hello World!</title>
</head>
<body>Hello World!</body>
</html>

Create a ConfigMap with the HTML from the file you just created:

$ kubectl create configmap hello-world --from-file index.html

Save the following to Kubernetes resource definitions into a file named hello-world.yml:

Turing Pi 2: 4 Raspberry Pi nodes on a mini ITX board

Last year I spent a bit of time building a Kubernetes cluster with the original Turing Pi. It was fun, and interesting, but ultimately the performance of the Compute Module 3+ it was designed around led me to running my homelab off some newer Pi 4 model B computers, which are at least twice as fast for almost everything I run on them.

Turing Pi 2

So this year, I was excited when the folks at Turing Pi sent me a Turing Pi 2 to test drive. And the board arrived just in time for Patrick Kennedy from ServeTheHome to challenge me to a cluster build-off at Supercomputing '21! Check out his ARM cluster build here.

Kubesail's PiBox mini 2 - 16 TB of SSD storage on a Pi

Kubesail Raspberry PiBox mini 2 front side exposed

Many months ago, when I was first testing different SATA cards on the Raspberry Pi Compute Module 4, I started hearing from GitHub user PastuDan about his experiences testing a few different SATA interface chips on the CM4.

As it turns out, he was working on the design for the PiBox mini 2, a small two-drive NAS unit powered by a Compute Module 4 with 2 native SATA ports (providing data and power), 1 Gbps Ethernet, HDMI, USB 2, and a front-panel LCD for information display.

The Hardware

The PiBox mini 2 is powered by the Compute Module 4 on this interesting carrier board:

PiBox mini carrier board with Raspberry Pi Compute Module 4

Why build a Raspberry Pi Cluster?

Raspberry Pi Cluster next to a banana for scale

After I posted my Raspberry Pi Blade server video last week, lots of commenters asked what you'd do with a Pi cluster. Many asked out of curiosity, while others seemed to shudder at the very idea of a Pi cluster, because obviously a cheap PC would perform better... right?

Before we go any further, I'd say probably 90 percent of my readers shouldn't build a Pi cluster.

But some of you should. Why?

Well, the first thing I have to clear up is what a Pi cluster isn't.

Note: This blog post corresponds to my YouTube video of the same name: Why would you build a Raspberry Pi Cluster?. Go watch the video on YouTube if you'd rather watch the video instead of reading this post!

Ignore noisy logs with fluentd in EKS or other Kubernetes clusters

Recently, I decided to use the fluentd-kubernetes-daemonset project to easily ship all logs from an EKS Kubernetes cluster in Amazon to an Elasticsearch cluster operating elsewhere.

The initial configuration worked great out of the box—just fill in details like the FLUENT_ELASTICSEARCH_HOST and any authentication info, and then deploy the RBAC rules and DaemonSet into your cluster, and you're off to the races (assuming your Elasticsearch instance is configured to allow access from the cluster!).

But once I did that, I noticed the brand new EKS cluster was sending over 16,000 log messages per second to Elasticsearch. Doing a tiny bit of analysis (not much was required, honestly), I found that over 98% of the logs were coming from two EKS-specific noisy containers, efs-csi-node and ebs-snapshot-controller.

Kubernetes 101 livestream series starts Nov 18th!

On November 18th, at 11 a.m., the first episode of my upcoming Kubernetes 101 livestream series will start on my YouTube channel.

Kubernetes 101 Series Artwork

The first episode will be available here on YouTube: Kubernetes 101 - Episode 1 - Hello, Kubernetes!.

You can find more details about the series on my Kubernetes 101 site, and there is also an open-source Kubernetes 101 GitHub repository which will contain all the code examples for the series.

In the spring, I presented a similar livestream series, Ansible 101, covering all the basics of Ansible and setting people up for success in infrastructure automation.

Raspberry Pi Cluster Episode 6 - Turing Pi Review

A few months ago, in the 'before times', I noticed this post on Hacker News mentioning the Turing Pi, a 'Plug & Play Raspberry Pi Cluster' that sits on your desk.

It caught my attention because I've been running my own old-fashioned 'Raspberry Pi Dramble' cluster since 2015.

Raspberry Pi Dramble Cluster with Sticker - 2019 PoE Edition

So today, I'm wrapping up my Raspberry Pi Cluster series with my thoughts about the Turing Pi that I used to build a 7-node Kubernetes cluster.

Video version of this post

This blog post has a companion video embedded below:

Raspberry Pi Cluster Episode 4 - Minecraft, Pi-hole, Grafana and More!

This is the fourth video in a series discussing cluster computing with the Raspberry Pi, and I'm posting the video + transcript to my blog so you can follow along even if you don't enjoy sitting through a video :)

In the last episode, I showed you how to install Kubernetes on the Turing Pi cluster, running on seven Raspberry Pi Compute Modules.

In this episode, I'm going to show you some of the things you can do with the cluster.