Learning Kubernetes with Diagrams (v1.35)

Hello

The base OS of the practice environment has been switched from Ubuntu 22.04 (Jammy) to 24.04 (Noble).

The reasons for the transition are as follows.

1. Support Period

Standard support for Ubuntu 22.04 ends in April 2027. Since 24.04 provides standard support until 2029 and security patches (ESM) until 2034, a stable practice environment can be maintained until 2034.

2. Kernel 6.8 — Full eBPF Support

In kernel 5.15 of 22.04, eBPF-based CNIs like Cilium operated in a partial fallback mode. In kernel 6.8 of 24.04, eBPF features such as full kube-proxy replacement and BPF Host Routing are fully supported.

3. cgroup v2 as Default

In 24.04, cgroup v2 is enabled by default, allowing for more precise resource management in containerd and kubelet. CPU/memory limits for containers are applied as intended.

4. Kubernetes Ecosystem Alignment

The official test environment for k8s 1.32 and above has been switched to Ubuntu 24.04. Package repositories for containerd, Docker, etc., are also being distributed based on the Noble (24.04) format.

The method for configuring the practice environment remains the same without any changes.

Key Changes

- Ubuntu 22.04 → Ubuntu 24.04 LTS

- x86_64 only → Simultaneous support for x86_64 + arm64 (Apple Silicon)

- Vagrant Box Version: sysnet4admin/Ubuntu-k8s: v1.0.0

The usage remains the same.

Since the box name remains the same, you can continue to use it just as before.

Vagrant automatically detects the host architecture (x86_64 / arm64) and

downloads the correct version.

Technically Verified Matters

- Confirmed normal operation with the combination of Kubernetes 1.35 / Containerd 2.2 / Calico v3.31

- Complete verification of major workloads (Deployment, StatefulSet, DaemonSet, Job, MetalLB, DNS) based on a 4-node cluster (cp + 3 workers)

- Testing completed in the same environment for both x86_64 and arm64

Not only Windows users but also Apple Silicon Mac users can use the same practice environment.

If you encounter any problems, please leave a question.

Thank you.

Best regards, Hoon Cho.

Hello

I updated the Calico CNI because there were issues where new Pods would not deploy or communication between nodes was cut off after returning from sleep mode.

■ Cause of the Problem

Calico uses short-term tokens for API server authentication and CNI configuration. Leaving the laptop in sleep mode causes the following two issues.

- Returning from sleep mode after more than 1 hour → calico-node fails API server authentication, unable to renew CNI token

- Returning from sleep mode after more than 24 hours → CNI token expired, unable to deploy new Pods

■ Action Taken

Upgraded Calico from v3.29.2 to v3.31.2 and applied a non-expiring Static Secret token.

Applied Courses:

- Kubernetes for Easy Start

- Kubernetes Learning Through Illustrations

- Prometheus Learning through Hands-on Practice

- Learning Grafana through Hands-on Practice

■ Test Status

- k8s_learning.kit : Completed (4 nodes Ready, no static token expiration)

- k8s_starter.kit : Completed (4 nodes Ready, No static token expiration)

- prom_learning.kit : Completed (4 nodes Ready, No static token expiration)

- graf_learning.kit : Completed (4 nodes Ready, No static token expiration)

■ For those currently using the existing environment

Method 1. Reconfigure the entire environment (Recommended)

vagrant destroy -f && vagrant up

Method 2. Re-apply Calico only (after connecting to cp-k8s)

kubectl delete -f https://raw.githubusercontent.com/sysnet4admin/IaC/main/k8s/CNI/calico-quay-v3.31.2.yaml

kubectl apply -f https://raw.githubusercontent.com/sysnet4admin/IaC/main/k8s/CNI/calico-quay-v3.31.2.yaml

For those setting up a new environment, it will be applied automatically without any additional action.

I hope this helps with your learning.

Best regards, Hoon Jo.

Hello

The code has been updated to support the current latest version, Kubernetes v1.35.

As I mentioned before, it's difficult to keep up with every single modification, but I think it would be beneficial in many ways to at least update the version.

I have uploaded it after organizing and testing.

The test status is as follows.

  Test Status

  ┌───────────────────┬────────┬────────────────┬───────────────────────┐
  │       Repo        │ Status │     Result     │         Notes         │
  ├───────────────────┼────────┼────────────────┼───────────────────────┤
  │ k8s_starter.kit   │ Done   │ 11 PASS (100%) │ Main merge on Sat     │
  ├───────────────────┼────────┼────────────────┼───────────────────────┤
  │ k8s_learning.kit  │ Done   │ 45 PASS (100%) │ Main merge on Sat     │
  ├───────────────────┼────────┼────────────────┼───────────────────────┤
  │ cicd_learning.kit │ N/A    │ -              │ Record only           │
  ├───────────────────┼────────┼────────────────┼───────────────────────┤
  │ prom_learning.kit │ N/A    │ -              │ Release in April      │
  ├───────────────────┼────────┼────────────────┼───────────────────────┤
  │ graf_learning.kit │ N/A    │ -              │ Release in April      │

I hope this helps with your learning.

Best regards, Hoon Cho.

Hello

In cases where it was difficult to proceed with vagrant up

I provided an OVA to guide you in setting up the lab environment more conveniently.

In this case as well

We've confirmed that various cases occur and certificate-related issues also arise together.

Accordingly, OVA will only be provided up to v1.30, and

From this point forward, we will guide you through performing manual updates.

A new directory called Manual-Setup has been created in ch2/2.3 for all lectures,

Example: https://github.com/sysnet4admin/_Lecture_k8s_starter.kit/tree/main/ch2/2.3/Manual-Setup

I hope this will reduce any issues you encounter when setting up your practice environment with this content.

Thank you.

Best regards, Cho Hoon.

I notice that the `` tags are empty - there is no Korean text between them to translate. The text that appears in the `` section would translate to: "We hope this will reduce any issues you may encounter when setting up your practice environment by following the content at ree/main/ch2/2.3/Manual-Setup. Thank you. Sincerely, Jo Hoon." However, since there is no text within the `` tags themselves, there is nothing to output.

I notice that the `` tags are empty - there is no Korean text between them to translate. The text that appears in the `` section translates to: "I hope this will reduce any problems you may encounter when setting up your practice environment by following the content at ree/main/ch2/2.3/Manual-Setup. Thank you. Sincerely, Jo Hoon." However, since there is no text within the `` tags themselves, there is nothing for me to translate according to your instructions.

Hello

The annual Kubernetes standard (trend) configuration is back! 🎉🎉🎉

The configuration is as follows, and the selection background and product description and original PDF are included in each path.

If you're thinking about what to study after learning the basics of Kubernetes, I strongly recommend that you start with a product related to your current foundational knowledge 🚀 from the following products!!!

Especially this year, there have been many changes in observability and data pipeline areas

You can focus on that part.

(Changes to Headlamp and Nginx Ingress are also important modifications.)

Description: https://github.com/sysnet4admin/_Book_k8sInfra/blob/main/docs/k8s-stnd-arch/2026/README.md

PDF: https://github.com/sysnet4admin/_Book_k8sInfra/blob/main/docs/k8s-stnd-arch/2026/2026-k8s-stnd-arch.pdf

Thank you.

Sincerely, Jo Hoon.

Hello

The Cyber Week period, which we discussed last time as the lowest discount period of the year, has been decided!!!

From December 1st to 9th, and it's based on North American time....

I think it might be from the afternoon of December 1st

On December 2nd, you should definitely be able to receive a 60% discount.

Therefore, if you are currently considering purchasing a certification exam voucher, please wait a little over a week

I recommend registering after that!!!

It felt bland with just text... so I'm attaching promotional video captures and links;;; but honestly, it doesn't have much significance; (;;;)

[Figure 1] From the promotional video (Link)

I'll come back to see you again with more good content.

Thank you.

Best regards, Johoon.

Hello

I'm uploading content that was presented at KubeCon North America, written in Korean in an easy-to-understand manner.

The Playground presented at KyvernoCon is short, so it should be easy to watch, and the Kubernetes scheduler content is composed of really interesting material, so I really hope you'll take a look. (That's why I also posted this content on Start Kube. / Not necessarily to look at the code, but to understand it at the level of "it's well-made")

[Figure 1] Kyverno Playground

[Figure 2] Kubernetes Scheduler

I'll come back with helpful content next time.

Thank you.

Best regards, Jo Hoon.

Hello

It seems like it's been a while since I brought Kubernetes exam discount information. 🙂

Actually, there have been occasional discounts before, but 40% is quite common, so...

While 50% isn't the absolute maximum discount, it's one of the biggest discounts available excluding Black Friday.

So if you have any exam plans!

I recommend taking the exam using this promotion code SEPT25BUN50!

Link: https://events.linuxfoundation.org/open-source-summit-korea/program/schedule/

Besides this, there's also a Kubestronaut bundle, so it might be good to check that out together...

Courses with over 50% discount are included, but since they're in English, you probably... won't be satisfied with them.

The period is based on US time, so it's slightly longer than tomorrow (September 26th+), but if you have exam plans, please register quickly and take the exam within a year. 😃

I'll bring more helpful information if I have any.

Thank you.

Best regards, Jo Hoon.