CKAD

I cleared the CKAD exam.

https://i.imgur.com/7IP1xMy.png

I took 3 attempts to clear this exam. In my first attemp, I had forgotten the concepts. I was not very confident during 2nd, and prepared well for the 3rd attempt to clear it.

I read "Kubernetes from Ground Up" again. Practised and "understood" the concepts better. With all these, the tests were actually very enjoyable.

Raspberry Pi Cluster - Fixing DNS Resolv on Master

I had setup a raspberry pi cluster, and suddenly the master became non-operational. The cluster was able to see itself, but if I login to master node, I noticed it was not able communicate externally.

The DNS Resolution for any site from master was failing.

Then I figured that Ubuntu had made some changes to resolve.conf protocol

Ubuntu requested users not to edit /etc/resolv.conf, and it's content on my cluster was not something that I wanted.

I had setup pihole, and my devices had started to see the internet through this. I noticed that Ubuntu since 18.04 had not set my router as the first nameserver and thus after pi-hole experiment, my master node lost its resolution capability

Fixing the Ubuntu DNS resolution was easy. I followed this post from datawookie

  1. resolvconf package was already installed.
  2. Edit /etc/resolvconf/resolv.conf.d/head
nameserver <pi-hole-server>
nameserver 8.8.4.4
nameserver 8.8.8.8
  1. Restart the resolvconf server
sudo service resolvconf restart

Thank you notes for Supporting Science

I had supported this project called "Modeling Is Key to Understand Processes, Structures and Scales!" by Mrs. Sexton of Montevideo Elementary School for the fifth graders. They had this project going on for the family science night in the winter of 2019.

On my birthday this year, I received a ton of thank you notes for the supporting this project. It felt amazing to see so many handwritten cards!

Thanks to students, and the teacher for this gesture. I will support your science efforts anytime! :)

Kubernetes Cluster Using Raspberry Pi

I setup a kubernetes cluster using Raspberry pi. It was much easier than I had imagined.

https://i.imgur.com/GlSDW8O.png

I used a Raspberry 4 for the master, and an agent. And I used two Raspberry B for two agents.

https://i.imgur.com/kCB1tq0.png

I setup using mhausenblas tutorial, which uses k3s for setting up of kubernetes on raspberry pis. I used k3sup tool for installation of packages, which worked well.

My overall goal ran into some challenges.

Givem all these, I still have the my local kubernetes cluster up and running and I am excited about the possiblities of using kubernetes on raspberry pis.

Book Review: The Manga Guide to Calculus

The Manga Guide to CalculusThe Manga Guide to Calculus by Hiroyuki Kojima
My rating: 2 of 5 stars

I tried to pick up some high-level intuition on the basics of calculus with this book, but I failed. Unlike, other Manga guides on electricity, and linear algebra, I found this book not very strong on the plot and I felt it did not present the story in a cohesive manner.

The concepts were introduced randomly, and I could not see how one built upon the previously introduced concept.

On the positive note, it did introduce very basics of calculus well, and I am eager to pick up other books on calculus with that foundation.

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Book Review: Journey to the Center of the Earth

Journey to the Center of the EarthJourney to the Center of the Earth by Jules Verne
My rating: 5 of 5 stars

This is a science-fiction adventure book. If you are a science-fiction fan, like me, then you are for a treat in reading in this book.

I really loved this book and the narration. It started as a simple story but quickly jumped to an adventure plot, and before I realized it had excellent science mixed into every element of this fictitious story. It has references to Fourier, Poisson and you find calculations for measuring the distances based on sound lag, it has adventures of an Iceland hiker, a cave explorer, a climber, and then you will you biologists in trilobite, yes, a trilobite! and then you find all the pre-historic animals and reference famous explorers, biologists, taxonomists all present in a single story.

When I choose the book, and read the plot, I wondered "How is this possible"? But when I read it, I was taken into a real adventure by the author.

I read this book in "Kindle-In-Motion" format, and illustrator, Killian Eng is a class on his own. He did excellent work and justice for this Jule Verne's timeless work.

Here are some of my notes and highlights from this book.

Here is something about Fourier.

Was it not always believed until Fourier that the temperature of the interplanetary spaces decreased perpetually?

About Poisson.

“Well, I will tell you that true savants, among them Poisson, have demonstrated that if a heat of 360,000 degrees existed in the interior of the globe.

A trilobite!

“Very well,” said he quietly, “it is the shell of a crustacean, of an extinct species called a trilobite. Nothing more.”

All these pre-historic animals.

leptotheria, mericotheria, lophiodia, anoplotheria, megatheria, mastodons, protopitheci, pterodactyls, and all sorts of extinct monsters here assembled together for his special satisfaction.

And the adventurers!

Mr. Milne-Edwards! Ah! Mr. de Quatrefages, how I wish you were standing here at the side of Otto Liedenbrock!”

This book was a thorough adventure, with so many references to explore further!

Book Review: Sita's Ramayana

Sita's RamayanaSita's Ramayana by Samhita Arni
My rating: 5 of 5 stars

I really enjoyed reading Samhita Arni's take on Ramayana, Sita's Ramayana, the story of Ramayana entirely narrated by Sita. It gives a new perspective to the entire story, while not-at-all deviating from the plot and details of the story.

As a reader who is familiar with the story, I picked up this book with a notion of what I can expect. However, I was still surprised and thoroughly enjoyed reading this story presented by an excellent writer (Samhita) and a fantastic illustration (Moyna Chitrakar).

Following this book, I became eager to check out other works of this author, and I found that her writings bring a freshness to the Indian mythology genre, and I am highly eager to read her next work "The Prince".



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Book Review: Hackers and Painters by Paul Graham

Hackers & Painters: Big Ideas from the Computer AgeHackers & Painters: Big Ideas from the Computer Age by Paul Graham
My rating: 4 of 5 stars

Enjoyed reading Paul Graham's essays. It is quite dated, for e.g, lots of reference to Web in the 1990s, 2000s time when Yahoo was a prominent .com company. Some of his opinions on wealth creation are still applicable in 2020. But we have to read his essays with plenty of skepticism. He sings praise for lisp and instills some desire in the reader to study lisp and start a startup.

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