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How to Use a Local Persistent Volume
TL;DR: A local persistent volume in a Kubernetes cluster is a persistent volume allocated in a certain node. Any pod mounting the volume will be automatically scheduled in the same node. Since it’s limited to 1 node, clearly it can’t be used as a high-availability solution, but hey, it’s quite Ok to use it for…
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Home Owner’s Guide to Free Gas Heating
TL; DR. No there’s no free natural gas but there’s free electricity, hope you don’t mind heating up your rooms with reverse cycle air conditioners instead My old house had an equally old gas heater, and we had been using it for years. 4 years ago, the heater broke down, so I had it replaced…
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How to Share Files on Linux Using Docker
Prerequisites: A Linux computer(mine is Fedora 36) Docker(or podman) installed I know, there’s traditional ways to share files over network such as samba or the very current cloud way such as Google Drive. Or I can just use a USB key. But I managed to impress my child(who has to use Windows because of her…
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How to Build Multi-Arch Docker Images for MacBook M1
At work, I currently use a MacBook Pro with an Intel chipset and some of my colleagues have upgraded to ones with M1 chipset which is of arm64 or aarch64 architecture. Then expectedly I need to build some Docker images for both architectures. I’ve done some multi-arch Docker stuff before so this is not really…
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How To Renew Certificates in Kubernetes Clusters, Revisited
There is a lot of TLS certificates used by the core of a Kubernetes cluster and a popular one is the client-server pair used by kubectl to authenticate to the cluster control plane. In my previous notes on how to renew certificates in a Kubernetes cluster with kubeadm, I found that the steps are quite…
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Home Battery, Worth Buying?
During the lockdown days in 2020, I got A Tesla Powerwall 2 + Backup Gateway 2 combo installed by Natural Solar. The total cost was A$14,000. “Is it worth buying?” or “Would it pay for itself?” those were the question I got asked a lot. With a full year’s data from 2021, I think I…
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Blog Deployed With Jsonnet, Grafana Tanka and ArgoCD
It’s been a year since I did the ‘Hello World’ with Jsonnet and Tanka, then I made a simple side-loader container to install Tanka as a plugin to ArgoCD and finally deployed an httpbin container with ArgoCD + Tanka + Jsonnet. However since Jsonnet wasn’t used in my work, those things were shelved afterwards. Recently…
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Easy Kubernetes Secret Integration with ExternalSecrets
In a Kubernetes cluster, A Kubernetes Secret is a resource type to hold sensitive data for the apps to use, such as an API key or database password. Secrets are namespaced so if I have RBAC access to a namespace, I can pretty much see all the secrets there, as the secrets are only base64…