-
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…
-
Passing Environment Variables to Terraform with RegExp
In a Terraform template, an input variable can be used to set some configuration point for a resource, such as In some scenario the input variable can get its value from an environment variable in the shell where terraform runs. It looks like This is handy where there is just a few variables. If there…
-
Share Environment Variables in GNU Make
I think writing up a cheat sheet for GNU Make and environment variables before Christmas is a good idea, right? In GNU Make, by default a single line runs in its own shell. ie. We can use backslash to fake multi-line like this: With .ONESHELL directive multiple lines in one target run in a same…
-
My Last Dota 2 Game
I started playing Dota 2 in 2014 because: It was a fun game Can run natively on Linux I picked it up again when the lock down started in 2020, and played quite a lot in the following months. Until I thought I have had enough Dota, because: The game was getting more complicated and…
-
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…