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Ivan Velichko

Building labs.iximiuz.com - a place to help you learn Containers and Kubernetes the fun way πŸš€

Diagram showing desired network policy configuration between frontend and backend pods
Featured Post

iximiuz Labs Update: More and Better Playgrounds and New DevOps Challenges

Hey, fellow server dweller πŸ‘‹ Ivan here with an exciting iximiuz Labs update! The month isn't over yet, so it's not quite time for the traditional monthly roundup. However, there have been so many updates on the platform in the past couple of weeks that they couldn't possibly fit into a single email. So, let's dive in πŸš€ Backend Revamp: Faster, Smarter, Stronger Over the past few weeks, I rolled out a significant backend rewrite at iximiuz Labs, and I couldn't be more excited to share the...

Hello πŸ‘‹ Ivan's here with November's roundup of all things Linux, Containers, Kubernetes, and Server Side πŸ§™ What I was working on This month was (extremely) development-heavy. Two-thirds of it went into the implementation of custom playground machinery and a new Kubernetes "Omni" playground, and in the last part, I was unexpectedly busy with expanding the platform's capacity and launching a new server in India πŸŽ‰ The latter became possible thanks to the support of all of you who got the premium...

Hello, fellow server dweller πŸ‘‹ I've got two exciting announcements to make. Starting with the shorter one, this year, I decided to give Black Friday a try. This is an experiment - iximiuz Labs hasn't done sales before and won't have any in the foreseeable future, at least not until next November. So, if you wanted to get a premium membership but the price felt too high, this is your rare chance to get it with a 50% discount. The offer is limited to exactly one week. Now, to the second, much...

Hello πŸ‘‹ It's this time of the month again! My traditional roundup of all things Linux, Containers, Kubernetes, and Server Side, delivered straight into your inbox πŸ“¬ What I was working on October was very productive for me - I shipped no major iximiuz Labs features (it's always hard to resist the temptation!) and instead dedicated all my available time to content work. The main focus was on Container Images. It's the subject of the first module of my "panoramic" Docker course, and it is almost...

Hey there, I’ve just finished putting together everything I know about Node.js container images and figured you might find the write-up useful. If you’re working with Node.js in Docker, chances are you’ve been hit by the dilemma of which base image to use. Do you go for the default node:latest, the slimmer node:22-slim, or something super minimal like a distroless image? What about Bitnami’s alternative β€” how does it stack up? Before you jump headfirst into your next build, you might want to...

Hello πŸ‘‹ Ivan's here with a slightly delayed September roundup of all things Linux, Containers, Kubernetes, and Server Side πŸ§™ What I was working on This month, I worked on an assorted set of topics. Skill Paths First off, the skill paths! I finally finished the underlying machinery, and now iximiuz Labs supports a new type of content - short roadmaps that you can use to develop or improve a specific skill: how to debug distroless containers, how to copy images from one repository to another,...

Hello friends! Ivan's here with another monthly roundup of all things Linux, Containers, Kubernetes, and Server Side πŸ§™ The issue's main topic is iximiuz Labs' largest-ever upgrade: Fresher and more streamlined look of the frontend UI πŸ’™ A new 5.10 Linux kernel built with nftables support (finally, we can try out kube-proxy's nftables mode). New default playground user - laborant (yep, rootless containers learning for). New playgrounds: Ubuntu 24.04, Debian Trixie, Fedora, and Incus (yay! more...

Hello friends! Ivan's here with a slightly delayed July roundup of all things Linux, Containers, Kubernetes, and Server Side πŸ§™ What I was working on This month, I got nerd-sniped by cgroups. It all started when I ran into a pretty significant difference in how Docker and Kubernetes handle the OOM events. When you limit the memory usage of a multi-process Docker container, the OOM killer often terminates only one of the processes if the container runs out of memory. If this process is not the...

Hey there πŸ‘‹ I spent a few weeks deep diving into cgroup v2, and I'm happy to share my findings with you! Everyone knows that Docker and Kubernetes use cgroups to limit the resources of containers and Pods. But did you know that it's very easy to run an arbitrary Linux process in a cgroup using much more basic tools? The only kernel's interface for cgroups is the virtual filesystem called cgroupfs typically mounted at /sys/fs/cgroup. Creating folders there and writing to files in them is...

Hello friends! Ivan's here with the June roundup of all things Linux, Containers, Kubernetes, and Server-Side craft πŸ§™ What I was working on The first two lessons (and a few challenges) of my "Alternative Introduction to Dagger" course have not sparked much interest among my students, so I had to put this work on pause. With a heavy heart, though, because I do like Dagger, and I was enjoying working on the content about it. But no interest means fewer iximiuz Labs Premium subscribers, and I...