Category: Opensource

  • Flyway Container, MySQL and SSL/mTLS

    Flyway is a handy utility to manage database schema migrations. Very similar to the schema migration mechanism in Ruby on Rails or Django, but Flyway is a standalone tool. So it’s best suited for some project which doesn’t have database schema management yet. I needed to use Flyway for a project I worked with, the […]

  • 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 […]

  • 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 […]

  • 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 […]

  • Kubernetes Jobs and Istio

    Note: the Job in the title refers to the Job resource in a Kubernetes cluster. At the time the Istio sidecar doesn’t play well with a Job or a Cronjob, because the istio-proxy might not be ready when the Job starts (which causes connection issues for the job) and won’t exit after the job finishes […]

  • Use Variables with Kustomize, Part 2

    I was looking at the Kustomize variable trick I did a year ago and I think I’ve learned some new tricks worth noting down. Variables are very handy most of the times, here’s a pattern to define a variable to be used in Kustomize templates and set its value via annotations. There you have it: […]