Phew! For Want of a Nail I was interested in learning how to Manage Resources for Containers. On the way, I learned and discovered: kubectl top Vertical Pod Autoscaler A (valuable) digression through PodMonitor kube-state-metrics `kubectl-patch Created a Graph References Kubernetes Resources Visual Studio Code has begun to bug me (reasonably) to add resources to Kubernetes manifests. E.g.: resources: limits: cpu: "1" memory: "512Mi" I’ve been spending time with Deislab’s Akri and decided to determine whether Akri’s primary resources (Agent, Controller) and some of my creations HTTP Device and Discovery, were being suitably constrained.

It’s a good name, I read it as “dapper” but I frequently type “darp” :-( Was interested to read that Dapr is now v1.0 and decided to check it out. I was initially confused between Dapr and service mesh functionality. But, having used Dapr, it appears to be more focused in aiding the development of (cloud-native) (distributed) apps by providing developers with abstractions for e.g. service discovery, eventing, observability whereas service meshes feel (!

I’ve spent time this week returning to the interesting Deislabs project Krustlet. Since the last time, the bootstrapping process has been simplified using Kubernetes Bootstrap Tokens. I know this updated process works with MicroK8s. Unfortunately, I’m struggling with it on GKE and thought I’d try DigitalOcean Managed Kubernetes. It worked first time! In the following, we run both the Kubernetes cluster and the Krustlet Droplet on DigitalOcean but, as long as the cluster and the VM are able to communicate with one another, you should be able to run these anywhere.

I developed an admission webhook for Akri, twice (Golang, Rust). I naively followed other examples for the generation of the certificates, created a 1.20 cluster and broke that process. I’d briefly considered using cert-manager recently but quickly abandoned the idea thinking it would be onerous and unnecessary complexity for little-old-me. I was wrong. It’s excellent and I recommend it highly. I won’t reproduce the v1beta1 and v1 examples from the Stackoverflow question as they should be self-explanatory.

I spent some time last week writing my first admission webhook for Kubernetes. I wrote the handler in Golang because I’m most familiar with Golang and because, as Kubernetes' native language, I was more confident that the necessary SDKs would exist and that the documentation would likely use Golang by default. I struggled to find useful documentation and so this post is to help you (and me!) remember how to do this next time!

I’m debugging an issue with Akri Zeroconf protocol in which Instance environment variables are no longer (!) being surfaced within the Broker pods. In my adventures, it seemed useful to better understand how Akri works and specifically, how Akri uses Kubernetes Device Plugins. IIUC plugins register with the Kubelet (!) via a gRPC service (Registration) that the Kubelet exposes on a UNIX socket at /var/lib/kubelet/device-plugins/kubelet.sock Then (!) if successful, devices should be reported by the Node’s metadata (spec) and available to be bound to Pods.

Let’s see if this works!? I’ve added the following link to this site’s baseof.html so that it is now rendered for each page: <link href="https://us-central1-webmention.cloudfunctions.net/webmention" rel="webmention" /> I discovered indieweb yesterday reading about webmention. Who knows what got me to webmention!? The principles of both are sound. Instead of relying on come-go behemoths to run our digital world, indieweb seeks to provide technologies that enable us to achieve things without them.

A Microsoft engineer introduced me to pest as a way to introduce service filtering in a ZeroConf plugin that I’m prototyping for Akri. It’s been fun to learn but I worry that, because I won’t use it frequently, I’m going to quickly forget what I’ve done. So, here are my notes. Here’s the problem, I’d like to be able to provide users of the ZeroConf plugin with a string-based filter that permits them to filter the services discovered when the Akri agent browses a network.

For the past couple of weeks, I’ve been playing around with Akri, a Microsoft (DeisLabs) project for building a connected edge with Kubernetes. Kubernetes, IoT, Rust (and Golang) make this all compelling to me. Initially, I deployed an Akri End-to-End to MicroK8s on Google Compute Engine (link) and Digital Ocean (link). But I was interested to create me own example and so have proposed a very (!) simple HTTP-based protocol.

You know when you start something and then regret it!? I think I’ll be sticking with Google Cloud Build; GitHub Actions appears functional and useful but I found the documentation to be confusing and limited and struggled to get a simple container image build|push working. I’ve long used Docker Hub but am planning to use it less as a result of the planned changes. I want to see Docker succeed and to do so it needs to find a way to make money but, there are free alternatives including the new GitHub Container Registry and the very very cheap Google Container Registry.