The Trend is Kubernetes (Beginner to Intermediate Edition)

📢 Finally Open! [Practical CKA Certification Perfect Preparation Course]

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Hello! I'm Ilpro 🙂

Happy New Year 2026!

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Starting with a proposal from the Inflearn manager last November, the CKA (Certified Kubernetes Administrator) course, which I have been planning, reinforcing, and refining day and night for four months, has finally opened 🎉

If this were a course simply for memorizing exam answers, it wouldn't have taken this long. Let me tell you about the 'three things' I put the most effort into while preparing for this course.

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1⃣ "Knowledge for the exam" vs. "Real-world practical knowledge"

Many people say that even after getting a certification, "it's daunting to apply it to real-world tasks." This course is structured around the core concepts and the trial and error I experienced while operating Kubernetes in the field. Therefore, it will provide you with the confidence to not only obtain the certification but also play a significant role in actual practical work.

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2⃣An "infinite practice environment" that feels more real than reality

To ensure you don't panic when you open the exam room door, we have built a practical hands-on environment that is 99% identical to the actual exam environment. Lectures you only watch with your eyes are quickly forgotten. Experience a curriculum where you learn by typing directly so that your hands remember first.

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3⃣A "high-quality curriculum" verified by students

We have already completed the first round of verification with many participants through the previous Inflearn Challenge ([Before 2025 ends] Let's get the Kubernetes CKA certification! with 1pro). Based on the valuable feedback received during the challenge, we have spent the last two months reinforcing the content and finely adjusting the difficulty level to ensure a seamless learning flow. Now, you will be learning with the most polished final version.

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Ultimately, this single course is all you need to understand Kubernetes and obtain your certification. 🙂

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That is why, if you have ever thought about obtaining the CKA certification, I encourage you to take on the challenge this time. I will be there to help you!

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Thank you.

I passed with 89 points 5 years ago. I thought I had solved all the problems without any unknowns, but I couldn't get a sense of where I might have gotten them wrong. A few days ago, I opened the current Sprint5 (Istio edition), and with the mindset of taking a break, I thought about creating a CKA course.

But when I looked at the exam guide again after a long time, there were so many changes;; (Above all, the registration fee...💰💰) I suddenly felt like it wouldn't be a relaxing atmosphere.

And I also wondered if I could quickly help students when I need to retake the exam myself, but the plan is in the link below.
🔗 KubeOps Community: https://cafe.naver.com/kubeops/835

Anyone interested in getting CKA certification together before this year ends?

Hello. It's been a while since I posted an event announcement!

Currently, the 5-month Sprint5 course production is in its final stages.

Since I'm not good at multitasking, I wasn't able to do any other activities besides Q&A during the 3 months I was focused on creating the course.

(I'm really envious of those who create courses and also do YouTube or various SNS activities ^^;)

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The Sprint5 Istio course is scheduled to open sometime next week, probably around Monday or Tuesday.

We are planning to hold an event for pre-reservations before opening.

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● How to Apply: [Cafe Event Post]Please leave a comment

● Application Deadline: Until before the course opens (Scheduled to open on November 17th or 18th)

● Benefit Information: After the course opens, a 40% discount coupon will be provided via message.

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Hello. This is Ilpro.

The DevOps field was added to the 4th Inflearn Warm-up Club, and I joined. So I am currently busy preparing for the study. The application notice is now up, so I will share the news with the students.

As for the study content, while taking the practical part of the lecture, [Kubernetes Another Class (On-the-ground) - Sprint 1, 2], you will follow the progress chart format I created below to complete the lectures, practical training, missions, and reviews.

Of course, the actual studying is done alone, but since we all communicate on Discord, we can increase our will to study by creating an atmosphere where others study together. Below, I have uploaded the OT materials that I am currently preparing, and there are also times when we meet online through OTs and midterms. Above all, there are benefits for doing well in all the courses!

The details are as follows, and we ask for your interest.

- Application period: May 2nd (Fri) ~ May 17th (Sat)

- Study period: May 23 (Fri) ~ June 20 (Fri)

- Graduation Ceremony: Friday, June 27th

- Participation link: https://inf.run/yShca

-Schedule

thank you

:) Hello. This is Ilpro.

I've been updating the course for the past 3 weeks. But I worked on a tight schedule day and night, so I got sick and just lay down for 3 days 😰

(I could have worked leisurely during the three days I was lying down..)

So the work was done last week, but I'm just now getting around to sharing the news 🎈 ^^

[The lecture patch contents are as follows]

• I checked all the practice content and corrected all the parts that were not working.

• We changed the practice materials room (kubetm blog -> Naver Cafe ) and added a summary of the lecture.

• I listened to all the lecture content and removed all unnecessary or ambiguous explanations.

• Subtitles were added for parts where pronunciation was ambiguous or where additional explanation was needed.

• I cut out all the long pauses between sentences when pronouncing them, which increased the speed of the lecture explanations.

• All lectures that were deprecated due to outdated content have been deleted.

• Course name change: The trend is Kubernetes [Beginner to Intermediate] -> The trend is Kubernetes [Beginner to Intermediate] that improves skills through theory and practice

And personally, the most noticeable change is the lecture cover .

This is a sign that has been around for a long time, but now that there are so many Kubernetes lectures, it's not so noticeable. So I worked hard to come up with ideas and changed it.

While I was working on updating the lecture, I tried to practice again and there were a lot of things that didn't work, so I did the practice with a really sorry heart. So if there are people who stopped the lecture because they had trouble practicing, 📣 I hope you come back and finish the lecture!

It looks like it's going to rain all day today, 🌧 I hope you take care not to catch a cold in the spring rain and have a nice day.

Hello. This is Ilpro.

It's late, but Happy New Year^^

I have one [news] to share with you.

Some of you may have already read the post in the cafe, but recently Inflearn held a contest for knowledge sharers called [Share Your Knowledge Sharing Experience], and I took this opportunity to write about my experiences and thoughts while doing knowledge sharing activities as a side job for the past four years.

Anyone can read it without having to join the cafe, so if there's anyone who's thinking about participating in knowledge sharing activities in the future, I recommend that you use it as a reference.

🌱 Knowledge Sharer - Year 1 of a Side Job (When is the best time to start a knowledge sharer?)
- Link: https://cafe.naver.com/kubeops/403
🌱 Knowledge Sharer - Second Year of Part-time Job (What Happened After Lectures Opened on Inflearn)
- Link: https://cafe.naver.com/kubeops/405
🌱 Knowledge Sharer - 3rd year of side job: (A promise made after experiencing conflict with a student)
- Link: https://cafe.naver.com/kubeops/406
🌱 Knowledge Sharer - 4th year of side job: (Changes brought to me by knowledge sharing activities)
- Link: https://cafe.naver.com/kubeops/408

Thank you as always, and if you have any questions during class this year, please feel free to ask!

Hello. This is Ilpro.

Currently, when installing Kubernetes, the image is not downloaded when kubectl init is run, and the following error occurs.

The reason seems to be that there is some problem with registry.k8s.io , and an issue is in progress on Github as shown below.

Link: https://github.com/kubernetes/registry.k8s.io/issues/294

There may have been some people who had trouble installing the app over the past few days, and we sincerely apologize for any inconvenience this may have caused.

I believe the issue will be resolved soon, but if you still want to try installing it quickly, please change the kubeadm init part of the downloaded script as follows.

 kubeadm init --pod-network-cidr=20.96.0.0/16 \ --apiserver-advertise-address 192.168.56.30 \ --image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \ --kubernetes-version v1.27.2

This is a repository provided by Alibaba Cloud in China. This is my first time using it, but I have confirmed that it is installed well.

Also, after installation, metrics-server will not be downloaded as shown below. You can ignore this as it only means that metrics information will not appear on the Dashboard.

 kube-system metrics-server-7db4fb59f9-zhqhq 0/1 ErrImagePull 0 2m26s

We will notify you again as soon as the issue is resolved.

thank you

Hello. This is Ilpro.

If you have seen the message below after installing Kubernetes with Virtualbox or if you feel that the VM is very slow, check if Hyper-V is currently being used. In conclusion, [Enable Netid VT-x/AMD-V] must be enabled for the CPU to be faster.

[Problem situation]

Bug: soft lockup - CPU#2 stuck for 32s! The VM slows down and I can't connect to it.

[Check status]

I unchecked Hyper-V with the contents below, but it is not actually reflected, so you may be using Hyper-V.

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[How to disable Hyper-V]



If you want to clearly check the virtualization usage status in Windows, download coreinfo from the link below and run it.

- Download: https://learn.microsoft.com/en-us/sysinternals/downloads/coreinfo

coreinfo -v

I am currently using AMD Ryzen and HYPERVISOR is not being used because it is checked.

And since SVM and NP are checked, [Native VT-x/AMD-V] can be activated normally.

If this is not checked, try the following:

1) Type "PowerShell" in the Windows search bar.

2) Right click on “Windows PowerShell”

3) Select "Run as administrator"

4) Enter the command below

Disable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-All bcdedit /set hypervisorlaunchtype off

Also, make sure that all the virtualization-related extended features in Virtualbox are checked. In particular, [Enable Native VT-x/ADM-V] must be checked.

(The feature check setting is now reflected in the Vagrantfile script.)

You can go into the actual VM (k8s-master) and check again whether it is reflected.

(The result must be a number greater than or equal to 1)

egrep -c '(vmx|svm)' /proc/cpuinfo

*The contents will be updated through the link below.

https://cafe.naver.com/kubeops/25