Kubernetes Made Easy (v1.35)

Hello, I'm Hoon Jo.

I have just returned from KubeCon Japan 2026 held in Yokohama last week. Since I have five presentations scheduled between August and November, I am sending them all at once. Four of them are domestic events, so there are sessions that shouldn't be too difficult to attend.

Tuesday, November 10, 17:30–18:00 MST

KubeCon + CloudNativeCon North America 2026, Salt Lake City

How Far Are Open-Source LLMs from Running Real Kubernetes Operations? A 10-Scenario Benchmark

There is much talk about running LLMs on Kubernetes. This presentation asks the opposite: Can LLMs operate Kubernetes? As the demand to integrate AI into incident response without exporting cluster states grows, and with open-source LLMs already running on single workstations, the options exist. We will reveal the results of measuring whether those options are actually viable through 10 failure scenarios.

View Official Schedule ›

For your information, after KubeCon North America ends, a Korean version of the video on Operating Kubernetes with Open Source LLMs will be uploaded to Grim Kuber.

4 other scheduled presentations

Tuesday, August 11, 17:15–17:45  ·  Open Source Summit Korea, Magnolia

GitAIOps: A 4-Layer Architecture for Predictable AI-Assisted Operations

This is a 4-layer architecture that ensures consistent results every time you entrust configuration deployment to an AI agent. We will demonstrate the process where records stored in the repository directly become the operational standard using an actual repository.

Session Info ›

Thursday, August 13, 14:20~14:45  ·  MCP Dev Summit Seoul, Orchid 1

AAIF Ambassador AMA: Building the Agentic Future Through Community Contribution

This is an open Q&A session featuring five AAIF Ambassadors. We will address the challenges encountered when deploying agents into actual production through questions from the audience.

Session Info ›

Friday, August 21  ·  OCP Korea Tech Day, COEX

GitAIOps: A 3-Layer Structure for Giving AI Agents Indelible Memories

This is a presentation in Korean. It begins with a demo where an agent answers questions from the audience using an open repository. It explains, through a three-layer structure, where and how memories must be stored for the agent to provide those answers.

Event Information ›

Wednesday, October 7  ·  Open Source Tech Day (ETRI), Yangjae aT Center (Detailed schedule TBD)

MCP, Before and After July 28: The Protocol's Past, Present, and the Future to Prepare For

This is a presentation in Korean. It summarizes which direction the July 28th spec revision has turned MCP toward, and what needs to be prepared now.

Please say hello if you see me there.

You can view the recap of the last KubeCon Japan and the list of previous presentations below.

View full list of presentations

KubeCon Japan 2026 Recap: kuberneteslab.dev/ko/archives/recaps/kubecon-japan-2026

Hoon Jo

CNCF Ambassador · AAIF Ambassador · Kubestronaut

kuberneteslab.dev  |  GitHub  |  LinkedIn  |  YouTube

Hello

I don't usually send out general announcements two days in a row if I can help it,

Seo Jong-ho (nickname: Gasida) is opening an online Mogakko (gathering to code together) study, so I am sharing this with you.

In particular, this study focuses on the newly released book, "Infrastructure Configuration and Deployment with Claude Code."

I feel a bit cautious and apologetic as if I am repeating myself since you have already received an email from me once before...

When I published the book "Claude Code" at the end of August last year,

I mentioned that they have a very good vision for technology, and the things they choose or proceed with are highly likely to eventually be chosen by the market.

[Figure 1] General announcement email sent at the end of August last year

Of course, at this point, there may still be some people who haven't had the chance to experience Claude Code yet (due to various circumstances...).

It seems correct that it has established itself as the mainstream and the definitive trend of the market.

In particular, this book strictly argues for doing Ops with Git + AI,

Once you truly implement and start operating (Ops) this, there will be no going back.

In that sense, because I really wanted as many people as possible to read it, I even adjusted the price of the book (by reducing the font size, using only one color, etc.)

I managed to bring the price down to the low 20,000 won range. (It’s usually very difficult to lower a book's price with a publisher. T_T)

[Figure 2] The book "Infrastructure Configuration and Deployment with Claude Code" on sale for 21,600 at Kyobo Book Centre

Seo Jong-ho, who is leading this Mogakko (coding together) session, is someone who has led numerous study groups and has created and shared truly impressive results.

So, I hope this study serves as an opportunity for everyone to learn about and adopt this new form of infrastructure deployment management!! You really won't regret trying it out.

[Study Application Information]

[4-Week Online Mogakko Recruitment - 'Infrastructure Configuration and Deployment with Claude Code']

(Author: Hoon Jo) The first infrastructure practice book for 'Building and Operating K8S with Natural Language' has been published.

Since AI tools are expected to play an expanding role in engineering tasks for construction and operations, I plan to start a "Mogakko" (group study) session using this book.

However, as a mechanism to ensure everyone finishes the book, I would like for us to study on the same schedule, share questions, and post brief summaries of what we've learned each week.

We look forward to your interest and participation.

----------------------------------

Recommended Participants: 'Infrastructure Engineers, DevOps' - Those who want to gain hands-on experience in initial setup and design decisions, and those with basic knowledge of K8S.

Book: Infrastructure Configuration and Deployment for Developers in the AI Era with Claude Code (Published 2026.6.19, 332 pages)

Book Link: https://product.kyobobook.co.kr/detail/S000220220936

Application: Until June 28th (Sun), complete and submit the application form https://forms.gle/aRJQhLjh8Vqm92vu6

Schedule: Start Week 1 (June 29) ~ Complete Week 4 (July 26) -> End of Mogakko meeting on July 27

- 1W(6.29~7.5) : Chapter 1,2(56p) - Overview, Setting up the practice environment(GKE)

- 2W(7.6~7.12) : Chapter 3,4(78p) - Deployment Pipeline(GitOps), Observability(Prometheus, Grafana, Loki)

- 3W(7.13~7.19) : Chapter 5,6(68p) - Zero-downtime Deployment(Blue/Green), Secret Management, Valkey Cache

- 4W(7.20~7.26) : Chapter 7,8,9(85p) - App of Apps pattern, Kafka/Tempo/CronJob, GitAIOps

Progress:

- After purchasing the book, please complete your self-study according to the schedule above, then write and post a brief summary to a public link.

- You can feel free to write and post your summary at any time between 'Monday and Sunday' for each respective week.

- You may freely choose any platform to share your content, such as a blog, GitHub, Obsidian, Notion, Facebook, or LinkedIn.

- Please join our team Slack workspace to facilitate discussions during learning and for announcements regarding the "Mogakko" (coding together) sessions among participating members.

- If the link to the summarized content for each week is not shared by every Sunday, the member will be disqualified.

Since I tend to have forward-thinking views on technology...

Please make sure to look at the book in person during a "Mogakko" (group coding) session or a weekend bookstore outing, and be sure to practice it yourself.

I hope as many people as possible realize how much of an impact Git + AI + Ops has, and

I hope you can consider introducing or applying it. (I truly mean it... T T)

(I would like to apologize in advance if it appears that you are receiving this twice unintentionally.)

I will strive to do work that helps everyone and to convey a positive direction.

Best regards, Hoon Cho.

Hello

Recently, the certification renewal process has changed so that obtaining the CKS now renews your CKA.

I believe some clarification is needed regarding this matter, so I have organized the details and am providing a general announcement.

https://www.cncf.io/blog/2026/06/17/expanding-care-passing-cks-can-now-extend-your-cka-certification/

Q: Upon passing CKS?

A: CKA is also automatically extended; when you obtain or renew the CKS (Security), the expiration date of your CKA (Administrator) certification will be extended to match the CKS.

Q: Does this not apply if the existing CKA has already expired?

A: No. You can take the CKS exam immediately without having to retake the CKA, and upon passing, even your expired CKA will be extended as a set.

Q: Can I still benefit from this even if I have never obtained a CKA?

A: No. You must have obtained the CKA at least once. As before, you must first obtain the CKA to be eligible to take the CKS exam.

Q: Will the existing CARE (Certification Advancement & Recertification Experience) be maintained?

A: Yes, it remains the case that obtaining CKS will also certify you for KCSA, and certifying for CKA or CKAD will certify you for KCNA. Therefore, if you were previously a "Kubestronaut" (i.e., if you held all 5 certifications)

You can re-acquire the "Kubestronaut" certification by re-certifying only two (CKS, CKAD) as follows.

CKS Exam/Renewal
   ├─→ CKS   (Self)
   ├─→ CKA   (New rule, June 18th~)
   └─→ KCSA  (Existing rule)

CKAD Exam/Renewal
   ├─→ CKAD  (Self)
   └─→ KCNA  (Existing rule)

[Figure 1] This means that even in this state, you only need to update CKS and CKAD to renew your "Kubestronaut" status.

I will be back with more helpful content.
Thank you.

(+ If anyone is coming to AppWorld Seoul on Wednesday, I'll see you then!)

Best regards, Hoon Jo.

Hello

It feels like it's been a while since I last sent out a mass email,

I am writing to introduce a new book that has just been released.

I believe most of you receiving this email are interested in "infrastructure" related topics.

In that sense, I feel that the way we handle infrastructure these days has changed so much,

I have written about how to handle infrastructure in the era of AI agents.

I believe we are in an era of paradigm shifts. In that sense, I think this will be very helpful.

Personally, I really liked this expression, so I wrote it in the preface.

In the AI era, new forms of opportunity will come to those who embrace change, while the greatest crisis will face those who stick to traditional ways.

It truly seems like we are in such an era. 🙂

Book Link:https://product.kyobobook.co.kr/detail/S000220220936

And even if it's not for the book, I would recommend visiting the GitHub link at least once.

Practice Guide https://github.com/sysnet4admin/_Book_GitAIOps

For completion reference https://github.com/sysnet4admin/notiflex-platform

And I would also like to inform you about a related event (free book 📖 giveaway) that we have planned.

I will be presenting on the topic above at F5 AppWorld Seoul (June 24th / Grand InterContinental Seoul Parnas), and the suggestion to give away books to attendees was accepted. Since books will be given to those who attend, it would be great if you could stop by, if you are nearby and have the time, to receive a copy! 😊

Attendance Registration Link: https://www.f5appworld.com/y922Xm?utm_source=CNCF&utm_campaign=26Q3_HE_apcj_korea_adsp_AppWorld-Seoul&utm_medium=platform&RefId=10&locale=ko-KR

(You must access and apply through the attendance application link!)

Free book giveaway event, please refer to the Gilbut blog or Instagram for more details.

Gilbut Blog: https://blog.naver.com/gilbutzigy/224313915186

Gilbut Instagram: https://www.instagram.com/p/DZeU4CxEVFb/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA%3D%3D

Thank you. I will be back with more helpful information. 👍

Best regards, Hoon Cho.

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.