Category: Free software

  • A Kubernetes ClusterSecret

    No, at this moment ClusterSecret, unlike ClusterRole, doesn’t officially exist in any version of Kubernetes yet. I’ve seen some discussion like this, so looks like it will be a while to have a ClusterSecret. But why do I need a ClusterSecret in the first place? The reason is very simple: To be DRY. Imagine I…

  • Hello World, Grafana Tanka

    I liked YAML a lot, until it gets longer and longer, and even longer. There are tools to make YAML ‘DRY’, the popular ones are Helm and Kustomize. But none of them can say it got the job done. To be honest, I didn’t like Helm much from the start. Helm uses templating syntax similar…

  • Rebuild a Kubernetes Node Without Downtime

    When I built the in-house Kubernetes cluster with Raspberry PIs, I followed the kubeadm instructions and installed Raspberry PI OS on the PIs. It was all good except the RPI OS is 32-bit. Now I want to install a Ubuntu 20.04 Server ARM64 on this PI, below are steps with which I rebuilt the node…

  • Ethereum(Crypto) Mining with Nvidia 3070(Ampere) on Ubuntu 20.04 with Renewable Energy

    I’ve done Crypto mining before and since the price is now almost all time high I’ll do that again, but only with my solar energy. Mining with dirty coal power isn’t ethical any more as the climate change has accelerated in the past few years. To start ETH mining here are some prerequisites: Energy efficient…

  • Kubernetes: How to Use Affinity

    Affinity is a great feature in Kubernetes to assign pods to nodes based on labels. In my case, I have a hybrid Kubernetes cluster with half nodes are of X86 architecture and other half of ARM architecture, and I need to deploy the X86 only containers to the X86 nodes. Of course I can build…

  • Kubernetes and GitOps with Flux CD V2.0

    GitOps could be the next big thing in cloud automation so I’d give it a try with my in house hybrid Kubernetes cluster. I was recommended to try Flux CD and there’s a good reference project initiated by my colleage: k8s-gitops. However, in order to fully understand how to use Flux CD, I chose to…

  • Hybrid Kubernetes Cluster (X86 + ARM)

    The one in the picture was my old laptop, then my daughter’s for a few years. Now she got a nice new 2-in-1 ultra book the school asked us parents to buy, this clunky one was gathering dust on shelves. I tried to sell it but got no one’s attention despite it has got i7…

  • Using Sealed Secrets in a Raspberry Pi Kubernetes Cluster

    Sealed Secrets is a bitnami Kubernetes operator aimed to one-way encrypt secrets into sealed secrets so that they can be safely checked-in into GitHub or other VCS. It’s rather easy to install and use Sealed Secrets in a Kubernetes cluster on AMD64 architecture, but not so on my Raspberry Pi cluster. First, the container image…