You want your side projects to help you get the job. They must demonstrate as achievements instead of hobbies. For this reason, I'd default to no, don't list side projects, unless you make it a strong argument for the position you're applying to. Are you a major contributor to a tech used in company? Have you written a book about it? Did you grow a community? Have you reached significant traction or revenue? Any yes…
I like your answer I just wonder: I used this project to teach myself kubernetes. If someone asks me how I know kubernetes what do I say? I suppose I say it was on a side project I did
All bonus points, especially if the company uses k8s or if you can answer aptly "why did you choose k8s?"
FWIW, I'd expect 3 kinds of answers: 1. "This was a right fit because..." 2. "I knew this was NOT a right fit but I wanted to learn" 3. "I thought it was the right fit but I was wrong because..."