Learn Kubernetes – Full Handbook for Developers, Startups, and Businesses
Learn Kubernetes – Full Handbook for Developers, Startups, and Businesses 관련
You’ve probably heard the word Kubernetes floating around, or it’s cooler nickname k8s (pronounced “kates“). Maybe in a job post, a tech podcast, or from that one DevOps friend who always brings it up like it’s the secret sauce to everything 😅. It sounds important, but also... kinda mysterious.
So what is Kubernetes, really? Why is it everywhere? And should you care?
In this handbook, we’ll unpack Kubernetes in a way that actually makes sense. No buzzwords. No overwhelming tech-speak. Just straight talk. You’ll learn what Kubernetes is, how it came about, and why it became such a big deal – especially for teams building and running huge apps with millions of users.
We’ll rewind a bit to see how things were done before Kubernetes showed up (spoiler: it wasn’t pretty), and walk through the real problems it was designed to solve.
By the end, you’ll not only understand the purpose of Kubernetes, but you’ll also know how to deploy a simple app on a Kubernetes cluster – even if you’re just getting started.
Yep, by the time we’re done, you’ll go from “I keep hearing about Kubernetes” to “Hey, I kinda get it now!” 😄
What is Kubernetes?
Imagine you're building a huge software platform, like a banking app. This app needs many features, like user onboarding, depositing money, withdrawals, payments, and so on. These features are so big and complex that it’s easier to split them into separate applications. These individual applications are called microservices.
So what are Microservices? Think of them like little building blocks that work together to create a bigger platform. So, you might have:
- One microservice for user onboarding
- Another for processing deposits
- Another for handling payments
- And many, many more!
To the user, it still looks like they’re using one smooth, unified banking app. But behind the scenes, it’s like a bunch of little apps working together to make everything run.
But here’s where things get tricky...
When you have dozens (or even hundreds) of these microservices, managing them becomes a nightmare. You might need to:
- Deploy each one separately
- Monitor them individually (to ensure they don’t crash/become slow due to too much load)
- Scale them (make them bigger to handle more users) as traffic surges, one by one
So, if your banking app suddenly gets millions of users, you'd have to manually tweak and update each microservice to keep it running smoothly. 😖 It’s a lot of work, and if something goes wrong, you’re in deep trouble.
This is where Kubernetes comes to the rescue! 🚀
Kubernetes is like a super-efficient manager for all these microservices. It’s a platform that helps you:
- Automate the deployment (getting the apps up and running)
- Scale the microservices (making them bigger or smaller as needed based on the inflow of traffic – your customers)
- Monitor them (keeping an eye on their health)
- Ensure reliability (so if one microservice breaks/fails, k8s replaces it immediately)
In simple terms, Kubernetes takes all your little microservices and organizes them, ensuring they run smoothly together, no matter how much traffic your app gets. It handles everything behind the scenes, like a conductor leading an orchestra, so your microservices work together without chaos.
How Applications Were Deployed Before Kubernetes
Before Kubernetes came into the picture, software teams had quite the juggling act when it came to deploying applications – especially when they were made up of lots of microservices.
One popular method was using a distributed system setup. Here’s what that looked like:
Imagine each microservice (like your user onboarding, payments, deposits, and so on) being installed on separate servers (physical computers or virtual machines). Each of these servers had to be carefully prepared:
- The microservice itself needed to be installed.
- The software dependencies it needed (like programming languages, libraries, tools) also had to be installed.
- Everything had to be configured manually ON EACH server.
And all of these servers had to talk to each other – sometimes over the public internet, or via private networks like VPNs.
Sounds like a lot of work, right? 😮 It was! Managing updates, fixing bugs, scaling up during traffic spikes, and keeping things from crashing could turn into a full-time headache for developers and system admins. 😖
Then Came Containers 🚢
A more modern solution that eased the pain (a little) was using containers.
So, what are containers?
Think of a container like a lunchbox for your microservice. Instead of installing the microservice and its supporting tools directly on a server, you pack everything it needs – code, settings, software libraries – into this single, neat container. Wherever the container goes, the microservice runs exactly the same way. No surprises!
Tools like Docker made this super easy. Once your microservice was packed into a container, you could deploy it on:
- A single server
- Multiple servers
- Or cloud platforms like AWS Elastic Beanstalk, Azure App Service, or Google Cloud Run.
🎉 Conclusion
Wow! What a journey we’ve been on 😄
We started by answering the big question — What is Kubernetes? We discovered that it’s not some mythical beast, but a powerful orchestration tool that helps us manage, deploy, scale, and maintain containerized applications in a smarter way.
Then, we took a step back in time to see how applications were deployed before Kubernetes — the headaches of manually installing software on servers, spinning up separate cloud instances for every microservice, and racking up huge cloud bills just to stay afloat. We also saw how containers simplified things, but even they had their own limitations when managed at scale.
That’s where Kubernetes came to the rescue
We explored:
- The problems Kubernetes solves – like auto-scaling, efficient resource management, cost savings, and seamless container grouping.
- Kubernetes architecture and components – breaking down complex terms like the cluster, master node, worker nodes, Pods, Services, Kubelet, and more, into simple, easy-to-digest ideas.
- Kubernetes workloads like Deployments, Pods, Services, DaemonSets, and StatefulSets, and what they do behind the scenes to keep our apps running reliably.
From theory to practice, we even got our hands dirty:
- We created a free Kubernetes cluster using Play with Kubernetes 🧪
- Deployed a real application using both imperative (direct command) and declarative (manifest file) approaches
- Understood why the declarative method makes our infrastructure easier to manage, especially when our systems grow.
Then we took a business lens 🔍 and looked at:
- The advantages of Kubernetes – from auto-scaling during traffic surges, to cost efficiency, and cloud-agnostic deployment.
- And also the disadvantages – like needing experienced DevOps engineers and not being ideal for every stage of a product's lifecycle.
Finally, we wrapped up with real-life use cases, highlighting when Kubernetes is a must-have, and when it’s better to wait – especially for early-stage startups still trying to find their audience.
So, whether you're a DevOps newbie, a startup founder, or just someone curious about how modern tech keeps your favorite apps online – you now have a strong foundational understanding of Kubernetes 🙌
Kubernetes is powerful, but it doesn't have to be overwhelming. With a solid grasp of the basics (which you now have 💪), you're well on your way to managing scalable applications like a pro.
Start simple. Grow smart. And when the time is right – Kubernetes will be your best friend.
Study Further 📚
If you would like to learn more about Kubernetes, you can check out the courses below:
About the Author 👨💻
Hi, I’m Prince! I’m a DevOps engineer and Cloud architect passionate about building, deploying, and managing scalable applications and sharing knowledge with the tech community
If you enjoyed this article, you can learn more about me by exploring more of my blogs and projects on my LinkedIn profile (prince-onukwili-a82143233). You can find my LinkedIn articles here (prince-onukwili-a82143233). You can also visit my website to read more of my articles as well. Let’s connect and grow together! 😊