Following up on my etcd playgrounds, here is a sneak peek of my latest work: a @containerd.dev‬ playground. As usual, it will be available on @iximiuz.bsky.social labs soon.

Starting some more looking into k8s things the way I usually do now, with a nice ephemeral k8s-omni playground from @iximiuz.bsky.social

Following up on my previous post, here is another tutorial about operating @openbao-official.bsky.social and @hashicorp.com Vault on @iximiuz.bsky.social Labs. Auto Unseal OpenBao/Vault with the Transit Secrets Engine: labs.iximiuz.com/tutorials/o... bsky.app/profile/did...

1/4 Secret management is a critical yet often overlooked aspect of DevOps. (Raise your hand if you've ever intentionally committed secrets to a Git repository.) This is why I've begun creating a series of educational content on the subject.

TIL that adding CAP_SYS_ADMIN to a k8s pod has different behaviour depending on the backing CRI. With Containerd it does nothing (you need to call it SYS_ADMIN) but on CRI-O it will add ok. Also TIL k8s doesn't validate the capabilities you add to pods!

Experimenting with using @iximiuz.bsky.social labs for interactive blog content, so I re-worked one of my container security fundamentals blogs labs.iximiuz.com/tutorials/co... . Interested in any feedback on what people reckon to the format :)

This is the way! 🚀

A Visual Guide to SSH Tunnels: Local and Remote Port Forwarding - Article by Ivan Velichko @iximiuz.bsky.social #Network #SysAdmin

labs.iximiuz.com a browser-based env's where anyone, from beginners to experienced engineers, can get hands-on experience with containers, K8S, DevOps tools, CI/CD pipelines, observability & loads more. Listen to @iximiuz.bsky.social how it's all started, current adaption: youtu.be/kHjAW7f0EPo

Please join me and thank @iximiuz.bsky.social for giving us a bunch of free premium accounts we can give away to our viewers on our twitch channel ! First two will be offered today !! @iximiuz.bsky.social really rocks ! Please take a look at his amazing labs !

Most of the issues with container images are not b/c of the app being containerized but a poorly written/structured docker file @iximiuz.bsky.social Kyle Quest will offer optimizations for improvements in size, security, & build speed, check out: gooddockerfiles.com

@iximiuz.bsky.social's journey of transitioning from traditional textual and visual explanations in his blog posts to creating interactive, reproducible tutorials -> labs.iximiuz.com has attracted 18,000 registered users, with around 2,000 active users per month. Full Ep -> youtu.be/kHjAW7f0EPo

Kubernetes "native" sidecars are slated for GA in 1.33, so it's a good time to brush up on how (and why) to use them. Solve this practical challenge by reworking a flawed pod, making it use a native sidecar: > Kubernetes Pod With a Faulty Init Sequence labs.iximiuz.com/challenges/k...

If you are into #docker and #containers you must check @iximiuz.bsky.social feed. His content is amazing.

Unpopular opinion: The main value of CKA, CKAD, and CKS is not in the certificate itself but in the preparation phase. Having said that, allow me to present a new iximiuz Labs challenge by Adam Leskis 👏 CKA Practice: Upgrade Multi-Node Kubernetes Cluster labs.iximiuz.com/challenges/c...

It's very easy to start a Docker container: docker run nginx ☑️ But can you explain what actually happens when you run this command? I prepared a Docker 101 challenge that helps you explore the internals of Linux containers - check it out: labs.iximiuz.com/challenges/s...

How to Limit CPU and Memory Usage of a Linux Process 🔽 Of course, using cgroups! But there is a number of ways to do it: - Manually editing the cgroupfs filesystem - Using libcgroup's cgcreate and cgexec - Using the mighty systemd-run Practice here 👉 labs.iximiuz.com/challenges/l...

k'exp by @iximiuz.bsky.social is a visual Kubernetes explorer #madewithvuejs that lets you explore Kubernetes capabilities & helps you with application development ✨ - https://madewithvuejs.com/kexp

How do you containerize a Python app the right way? 🤔 Building small and secure images for Python projects is surprisingly hard: - Which base image to choose? - How to manage dependencies? - How to structure the Dockerfile? Learn more (with solutions): labs.iximiuz.com/challenges/d...

Container images to avoid in production - part II: python:3 Yes, it's a Docker Official Image, and it's a good image to build your app, but: - It has TWO pythons inside 🐍 x 2 = 🤯 - It brings 800MB+ of dev/build packages. What to use instead in production 👉 python:3-slim

SSH Tunnels: An age-old trick that's still widely used - Expose a local service to the Internet - Map a remote service to a local port - Query an AWS RDS database with a local GUI client - Access a server in your private VPC from a dev machine ...and a lot more. Visual memo 👇

What's Inside Distroless Container Images: Taking a Closer Look 🧐 Distroless images come in many flavors, and it might not be obvious which one (if any!) is the best fit for your application. Here is my attempt to explain the difference and use cases on a single diagram:

Pulling and Pushing Container Images 🔽 Did you know that the below commands: docker pull nginx docker pull nginx:latest docker pull library/nginx:latest docker pull docker[.]io/library/nginx:latest ...pull exactly the same Docker Hub image? Learn more 👉 labs.iximiuz.com/skill-paths/...

Building container images FROM scratch? Then you need to be aware of these pitfalls 👇 By default, scratch containers lack: - Rootfs layout - CA certificates - Time zone info - Shared libraries - /etc/{passwd,group} Learn more in my new blog post: labs.iximiuz.com/tutorials/pi...

How To Build a Production-Ready Container Image For a Go App 🔽 Is "FROM scratch" good enough for you? Check out these hands-on challenges to learn about the most typical Go container pitfalls: - static linking labs.iximiuz.com/challenges/d... - dynamic linking labs.iximiuz.com/challenges/d...

How Container Networking Works 🧵 1/6: Network namespaces (netns) A separate network namespace gives a Linux container its own virtualized (and fully isolated from the host) network "context" - a loopback device, a route table, netfilter/iptables rules, etc.

Have big and slow containers? Not keeping up with CVEs in your images? We (me and @iximiuz.bsky.social ) can try to help! Send over your Dockerfile, and we’ll provide a refined version in return. A limited time offer 🙂

Computer Networking 101: Forward Ports Like a Pro 🧙‍♂️ The only way to mastery is through practice. Can you map one port to another using: - socat labs.iximiuz.com/challenges/p... - netcat labs.iximiuz.com/challenges/p... - iptables labs.iximiuz.com/challenges/p... Happy hacking!

62 practical exercises if you're preparing for a DevOps, SRE, or Platform Engineer interview 🔽 All challenges: - Have automated solution checking - Packed with hints and theory references - Based on real-life problems I've encountered Check them out: labs.iximiuz.com/challenges

If you want to start building better container images for your Node.js applications, I've got some hands-on resources for you 👇 Check out my latest DevOps challenge, packed with practical tips: > Build a Production-Ready Next.js Application Image labs.iximiuz.com/challenges/d...

Are your Docker images huge and full of CVEs? 🐳 Multi-stage builds and careful base image selection can fix that. Read my multi-stage builds intro to understand the How's and the Why's and get practical examples for Node.js, Go, Java, Rust, and PHP: labs.iximiuz.com/tutorials/do...

I haven't been keeping a close eye on it, but it turns out cdebug has been steadily growing on GitHub! It's feature-complete, so if you're tackling a tricky container debugging issue, I've got a tool for you 😎 github.com/iximiuz/cdebug

Confused by Docker image options for Node.js? Dealing with huge containers and noisy vulnerability scans? Been there, too! 🙈 Check out my tutorial on choosing the optimal Node.js base image for your app: labs.iximiuz.com/tutorials/ho...

New year, new goals! 🚀 If you’re learning Linux, containers, networking, or Kubernetes, I’ve got you covered: - 30 free online playgrounds - 60 interactive DevOps challenges - Tutorials, courses, and skill paths Level up your server-side game! labs.iximiuz.com

The last Server Side roundup of the year is out 🚀 - Tasks Dev Tools - 6 new DevOps challenges - iximiuz Labs 2024 in review - A bunch of great reads ...and more! Give it a read if you're into Linux, containers, or Kubernetes 👇 newsletter.iximiuz.com/posts/ivan-o...

If you want to practice some Linux & Networking, I've got two "classic" sysadmin problems for you: - Which Port Is a Service Listening On? labs.iximiuz.com/challenges/l... - Which Process Is Listening on a Port? labs.iximiuz.com/challenges/l... How fast can you solve them?

Docker Containers vs. Kubernetes Pods 🔽 - How are Pods implemented under the hood? - What is the actual difference between a Pod and a Container? - What would it take to create a Pod using regular Docker commands? Find the answers in this post: labs.iximiuz.com/tutorials/co...

Containers Pro Tip: You can inspect the rootfs on any container image, including viewing textual files, by simply opening a URL like: ima.ge.cx/docker.io/library/nginx

A huge quality of life improvement for folks creating playgrounds or authoring content on iximiuz Labs: Tasks Dev Tools 🚀 Inspect the status, duration, stdout, stderr, and other attributes of the init and regular tasks in a slick new UI. Start here 👉 labs.iximiuz.com/playgrounds/...

The best Christmas/New Year gift for a software engineer? Fun education! 😎 Treat yourself with a bunch of endorphin injections by cracking interactive Linux, networking, Docker, and Kubernetes puzzles and dive into quality long reads on the same topics: labs.iximiuz.com/premium

Continuing the topic of Docker gotchas 👻 A poplar Node.js Dockerfile mistake - using npm in the CMD or ENTRYPOINT. Example: CMD ["npm", "start"] Scripts from the package.json are executed by npm in sub-shells, and this breaks the signal propagation. Practice 👇 labs.iximiuz.com/challenges/g...

How using an entrypoint script can break the container's graceful termination 🔽 A new Linux & Docker challenge: Can you fix the graceful termination for this containerized Go application? labs.iximiuz.com/challenges/g...

Why Set GOMEMLIMIT for Go Apps in Containers/Kubernetes Pods? 🔽 - Linux containers isolate network and fs but share host CPU cores/RAM. - cgroup memory limits aren’t considered by the Go runtime. - The Go GC assumes the host’s total memory. - Ignoring cgroup limits risks terminations by OOM Killer.

What’s new on iximiuz Labs: - More disk, CPU, and RAM for the most popular playgrounds - New Python playground - Two extra flavors of the K8s Omni playground (calico and static routing) - New “Asia” region to improve local experience …and more! 👇 newsletter.iximiuz.com/posts/iximiu...

Did you know that a typical Docker container has a full-blown Linux distro inside? There are exceptions like `FROM scratch` and distroless images, but their usage is still far from common adoption. To understand what's inside of your containers 👇 labs.iximiuz.com/challenges/s...

The very first CKA-focused challenge on iximiuz Labs 🥳 - Practice configuring Network Policies to restrict traffic between Kubernetes pods. labs.iximiuz.com/challenges/c...

Play with the new Kubernetes 1.32 release in my Kubernetes "Omni" Playground: - { containerd, cri-o } runtimes - { flannel, cilium, calico, static, none } networking A grand total of 10 Kubernetes "flavors" for all sorts of free-form experimentation! 🚀 labs.iximiuz.com/playgrounds/...

Allow me to introduce the 30th iximiuz Labs Playground: Python! 🎉 • Always up-to-date with the latest Python 3.x • Easily switch between versions using pyenv • Manage packages at lightning speed with uv • VS Code, Docker, and more Spins up in ~5s 🚀 labs.iximiuz.com/playgrounds/...

Did you know you can explore your Kubernetes clusters visually on iximiuz Labs? 🧐 Every Kubernetes playground comes equipped with k'exp - an exploration-tailored Kubernetes UI that I wrote some time ago. Here is me poking around in the K3s playground labs.iximiuz.com/playgrounds/... 👇

Containers vs. Pods: What's the real difference? 🤔 Kubernetes Pods go beyond Docker containers by sharing namespaces, simplifying IPC, and mimicking VMs - all while being implemented under the hood with containers. Learn how to recreate Pods with Docker 👇 labs.iximiuz.com/tutorials/co...