IMTI

Architecting, Developing, SRE, DevOps, AI/ML

Kubernetes Custom Upstream DNS

Customize upstream DNS resolution.

Customize the Upstream Nameservers used by kube-dns by Pods when looking up external hostnames from within a Kubernetes cluster. I found that adding custom Upstream Nameservers to my kube-dns solved many issues encountered in in the past with external hostname resolution on individual Pods.


Ingress on Custom Kubernetes

Setting up ingress-nginx on a custom cluster.

There are more than a handful of ways to set up port 80 and 443 web ingress on a custom Kubernetes cluster. Specifically a bare metal cluster. If you are looking to experiment or learn on a non-production cluster, but something more true to production than minikube, I suggest you check out my previous article Production Hobby Cluster, a step-by-step guide for setting up a custom production capable Kubernetes cluster.


kubectl Context Multiple Clusters

Managing multiple clusters with kubectl.

I use a few Kubernetes clusters on a daily basis, and I use kubectl to access and configure them from my workstation. There are dozens of ways to configure kubectl however I find the following method the easiest for me to manage and not make a mess.


Formatting Drives on MacOS

A stack of old drives, a terminal and diskutil.

I have had this collection of old external drives hanging around for years. There was a time I was having terrible luck with hard drives. It turned out I managed to amass a collection of about eight drives from one terabyte to four terabytes.


Kubectl x509 Unable to Connect

Kubernetes remote access and TLS certs.

Just set up a brand new cluster? Changed the domain or IP of your admin node? Then you may have encountered the error Unable to connect to the server: x509: certificate is valid for …. The following is a fix for this common issue. However, there are often other reasons to rebuild your cluster cert, and it’s relatively easy.


Production Hobby Cluster

Production-grade cluster on a hobby budget.

Setting up a production-grade Kubernetes cluster can be done on a hobby budget, and if this is true why mess around with a lesser grade. If you are investing time to learn distributed cloud computing or microservices, is the distance between $0 and 15 dollars a month worth the time in translating best practices? Kubernetes is designed to host production applications. My personal web applications may only be hobbies, but they might as well be production grade hobbies.


rSync Files on Interval

Sync media to Raspberry Pi or any ARM SoC.

A recurring requirement for my IOT projects involves keeping a set of files synced with a central server. Many of these projects include media players, kiosk systems, or applications that need frequently updated configuration files, all while entirely unattended, and in most cases unreachable through firewalls. I have one project that alone has 2000+ devices pulling media continuously from an rsync server. Many of these devices are on doggy wifi networks.


SQL Foundations

Selects, joins and aliases.

The following is an attempt at explaining the basics of an SQL query, and more importantly how I believe you can best think through them. All queries can be broken down into the basics of this declarative language.


Burn SD Images on MacOs

Use the command line to burn SD cards, easy and fast.

Use your terminal to burn images fast and easy with dd. I do a lot of professional and hobby development for projects using devices such as Raspberry Pi, Orange Pi, Libre Computer, Tinker Board, etc. I run across a lot of tutorials with people downloading and using big GUI apps with clunky drag and drop interfaces to burn images.


Kubernetes - 413 Request Entity Too Large

Configuring the NGINX Ingress Controller

When setting up nginx ingress on Kubernetes for a private Docker Registry, I ran into an error when trying to push an image to it.


Kubernetes Remote Control

Using kubectl to Control a Remote Kubernetes Cluster

I use Minikube to run a local Kubernetes single node cluster (cluster?). However, I also work with a custom production cluster for work. This cluster consists of development and production nodes. I often need to switch between working on my local Minikube and the online Kubernetes cluster.


Microservices & Kubernetes

Overview

The following is a collection of articles, videos, and notes on Microservices. The Microservices architecture is a variant of the service-oriented architecture (SOA), a collection of loosely coupled services.


Don't Install cqlsh

Containers as utility applications

We live in a world of process isolation and tools that make utilizing it extremely simple, with apps like Docker we can perform dependency management with dependency isolation. As I am slowly becoming a fanboy of containerization, I look forward to the day when typing ps on my local workstation or remote server is nearly synonymous with commands like docker ps or kubectl get services.


Don't Install Emacs

Containers as utility applications

I grew up on emacs. One of my first jobs I sat down at a terminal and was editing some files with pico, it’s what I knew since I used that fantastic email client pine. I was quickly told by my the lead developer that I need to use a real text editor if I’m going to progress in my career. He told me I need to try emacs, and after suffering through a few weeks of memorizing multi command-char sequences and training the muscle memory in my pinky to perform bizarre contortions of my left hand just to save my file, I became a convert. I found out a few months later that the developer who convinced me to use emacs was a vi user all along. I think I was a victim of a cruel joke or hazing ritual, but I learned to love emacs, and when I am not coding in a desktop IDE (IntelliJ) then I am using emacs.


Kubernetes Overview

Container Orchestration & Microservices

Getting started with Kubernetes for local development. I develop on a Mac however much of this is easily translated to windows.


Raspberry Pi - Serial Number

Getting the unique serial number from a Raspberry Pi.

Getting the unique serial number from a Raspberry Pi.