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Grant a Service Account an IAM Role in AWS/GCP
How to grant a pod running in a Kubernetes cluster necessary permissions to access cloud resources such as S3 buckets? The most straight forward approach is to save some API key in the pod and use it to authenticate against cloud APIs. If the cluster is running inside the cloud, an IAM role can then…
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I Farmed Some Chia(XCH)
Chia is a relatively new crypto currency which can be ‘mined’ with hard disks. It’s advertised as a green crypto because hard disks consumes way less energy comparing to mining rigs with high end graphic cards. I installed Chia on my Ubuntu Linux desktop computer because it has some vacant SATA ports that I can…
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TLS Full Site Encryption with Istio and Let’s Encrypt
These are steps to easily install TLS certs to a Kubernetes cluster with Istio service mesh as ingress controller, provided by Let’s Encrypt‘s awesome certbot. Installation of the certbot (on Ubuntu Linux 20.04LTS) The certbot can be install via snap on Ubuntu Linux By default certbot needs to write to system directories which I thought…
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A Kubernetes ClusterSecret
No, at this moment ClusterSecret, unlike ClusterRole, doesn’t officially exist in any version of Kubernetes yet. I’ve seen some discussion like this, so looks like it will be a while to have a ClusterSecret. But why do I need a ClusterSecret in the first place? The reason is very simple: To be DRY. Imagine I…
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Real Life Cost of a Tesla Model 3
It’s been a bit more than 2 weeks since I got my Model 3 as a result of my impulse-buying, so as an end user I think I’m qualified to do some cost analysis and projection based on the first 1000km I’ve done with the car. Disclaimer: The following analysis is based on my calculation…
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Hello World, Grafana Tanka
I liked YAML a lot, until it gets longer and longer, and even longer. There are tools to make YAML ‘DRY’, the popular ones are Helm and Kustomize. But none of them can say it got the job done. To be honest, I didn’t like Helm much from the start. Helm uses templating syntax similar…
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Never Buy a Tesla
I just got my Tesla Model 3 delivered last week and I’ve added a few hundreds of KMs to its odometer. Frankly it’s largely a disappointment and I’ll state my reasons here. First, it doesn’t have a ‘start engine’ or ‘ignition’ button at all! More to that, it doesn’t have an engine either, only electric…
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Rebuild a Kubernetes Node Without Downtime
When I built the in-house Kubernetes cluster with Raspberry PIs, I followed the kubeadm instructions and installed Raspberry PI OS on the PIs. It was all good except the RPI OS is 32-bit. Now I want to install a Ubuntu 20.04 Server ARM64 on this PI, below are steps with which I rebuilt the node…