Category: Systems Admin

  • 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 […]

  • Using Nginx to Negate Brute Force Attacks on WordPress Sites

    Thanks to the Prometheus – Grafana combo I set up earlier for my Kubernetes cluster I noticed that there was a steep increase of requests to this blog started a few days ago. I checked my Google Analytics dashboard, sadly my blog didn’t become any popular at all. So it must be some sort of […]

  • 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 […]

  • Sideloader: An InitContainer to Sideload Stuff to Your Main Container

    After having played with ArgoCD for a few days, I came cross a blog post on how to get Grafana Tanka to work with ArgoCD. I like the idea to have Tanka as a plugin of ArgoCD, because: The main ArgoCD docker image doesn’t get bloated by all those binaries we want to use with […]

  • Run ArgoCD with Istio Service Mesh in a Kubernetes Cluster

    It’s been quite a while since I installed Flux CD V2 in my garage Kubernetes lab, as there’s a lot of debate going on between Flux and ArgoCD I decided to give ArgoCD a go. The other reason to try ArgoCD is that it supports Jsonnet. By default installation, ArgoCD will use self-signed TLS certificate […]

  • Update GCP IAM Adaptively with Terraform DataSources

    In a scenario where a service account in a central GCP project needs to be accessible by a group of GKE service accounts across multiple GCP projects, the IAM part in Terraform HCL could look like I can make a variable for the members so it becomes But still the project_ids variable needs to be […]