Tag: kubernetes

  • Better Resilience for Kubernetes Pods

    I happened to notice that all 3 pods serving this blog in my Kubernetes cluster were allocated to a same node. I thought Kubernetes will try its best to shuffle pods of a deployment into different nodes by default but guess I expected too much. Note the knode3 below Have you spotted the problem? In […]

  • How to Regulate Egress Access in Kubernetes with Istio

    Usually I don’t mind to give pods unlimited egress access, ie. the pods I deployed can access the whole internet if it needs to. However when the pods take input from users it’s a whole different story. For example, running some sandbox applications such as an online Python learning environment, the workload can be abused […]

  • Some Tips for CKA Exams

    I’ve passed my CKA exam on my first attempt, it’s not hard because it’s the entry level certificate for Kubernetes but still a good preparation is necessary even for someone already experienced in Kubernetes. First of all, the exam is fully hands-on: every question requires a set of commands done in a terminal provided in […]

  • Deploy the Loki Stack in a Kubernetes Cluster with ArgoCD

    Loki and Promtail from Grafana Labs are new kids in the observability community. Are they good enough to replace Elasticsearch and Logstash? I would like to see. Here’s a sample ArgoCD Application to deploy Loki, Promtail, Prometheus and Grafana all from 1 Helm chart: grafana/loki-stack. Some settings of my installations are: loki, grafana and prometheus […]

  • Fixed CoreDNS High CPU Issue in a Kubernetes Cluster

    There was a Grafana alert saying that CPU usage was quite high on the master node of my garage Kubernetes cluster. I was watching a movie so I didn’t jump into this right away 🙂 I had a look at the master node today and this is how I fixed this issue. With the good […]

  • An Canary Upgrade of Istio 1.9 to 1.11

    Prerequisites: full Admin access to a Kubernetes cluster, which has an older version of Istio installed. A while ago I decided to try Istio in my garage Kubernetes lab, and replaced ingress-nginx with istio-ingressgateway. At the time being I installed Istio 1.9.4, the latest release is already 1.11.4. To avoid being left in the deprecated […]

  • Running Minecraft Server in Kubernetes Cluster

    A month ago I had an idea to run a Minecraft server in my garage Kubernetes lab. I though it might interest my little Minecraft player at home with some Kubernetes and GitOps stuff but that failed miserably. But at least I knew how to host a Minecraft server in Kubernetes, with ArgoCD too. First […]

  • ArgoCD, Jsonnet and Tanka

    Ever since I’ve installed ArgoCD in my garage Kubernetes lab, I wanted to make Tanka work with ArgoCD, so that I can do GitOps with Jsonnet, in addition to YAML, kustomize and helm charts. I was hugely inspired by(read: copied and pasted from) this blog post. Here are the steps I made Tanka worked as […]