PlatformEngineering

When you think about Kubernetes, you might picture a vast orchestra with dozens of instruments, each critical for delivering a grand performance. It’s perfect when you have to manage huge, complex applications. But let’s be honest, sometimes all you need is a simple tune played by a skilled guitarist, something agile and efficient. That’s precisely what K3s offers: the elegance of Kubernetes without overwhelming complexity.

What exactly is K3s?

K3s is essentially Kubernetes stripped down to its essentials, carefully crafted by Rancher Labs to address a common frustration: complexity. Think of it as a precisely engineered solution designed to thrive in environments where resources and computing power are limited. Picture scenarios such as small-scale IoT deployments, edge computing setups, or even weekend Raspberry Pi experiments. Unlike traditional Kubernetes, which can feel cumbersome on such modest devices, K3s trims down the system by removing heavy legacy APIs, unnecessary add-ons, and less frequently used features. Its name offers a playful yet clever clue: the original Kubernetes is abbreviated as K8s, representing the eight letters between ‘K’ and ‘s.’ With fewer components, this gracefully simplifies to K3s, keeping the core essentials intact without losing functionality or ease of use.

Why choose K3s?

If your projects aren’t running massive applications, deploying standard Kubernetes can feel excessive, like using a large truck to carry a single bag of groceries. Here’s where K3s shines:

Edge Computing: Perfect for lightweight, low-resource environments where efficiency and speed matter more than extensive features.
IoT and Small Devices: Ideal for setting up on compact hardware like Raspberry Pi, delivering functionality without consuming excessive resources.
Development and Testing: Quickly spin up lightweight clusters for testing without bogging down your system.

Key Differences Between Kubernetes and K3s

When comparing Kubernetes and K3s, several fundamental differences truly set K3s apart, making it ideal for smaller-scale projects or resource-constrained environments:

Installation Time: Kubernetes installations often require multiple steps, complex dependencies, and extensive configurations. K3s simplifies this into a quick, single-step installation.
Resource Usage: Standard Kubernetes can be resource-intensive, demanding substantial CPU and memory even when idle. K3s drastically reduces resource consumption, efficiently running on modest hardware.
Binary Size: Kubernetes needs multiple binaries and services, contributing significantly to its size and complexity. K3s consolidates everything into a single, compact binary, simplifying management and updates.

Here’s a visual analogy to help solidify this concept:

This illustration encapsulates why K3s might be the perfect fit for your lightweight needs.

K3s vs Kubernetes

K3s elegantly cuts through Kubernetes’s complexity by thoughtfully removing legacy APIs, rarely-used functionalities, and heavy add-ons typically burdening smaller environments without adding real value. This meticulous pruning ensures every included feature has a practical purpose, dramatically improving performance on resource-limited hardware. Additionally, K3s’ packaging into a single binary greatly simplifies installation and ongoing management.

Imagine assembling a model airplane. Standard Kubernetes hands you a comprehensive yet daunting kit with hundreds of small, intricate parts, instructions filled with technical jargon, and tools you might never use again. K3s, however, gives you precisely the parts required, neatly organized and clearly labeled, with instructions so straightforward that the process becomes not only manageable but enjoyable. This thoughtful simplification transforms a potentially frustrating task into an approachable and delightful experience.

Getting K3s up and running

One of K3s’ greatest appeals is its effortless setup. Instead of wrestling with numerous installation files, you only need one simple command:

curl -sfL https://get.k3s.io | sh -

That’s it! Your cluster is ready. Verify that everything is running smoothly:

kubectl get nodes

If your node appears listed, you’re off to the races!

Adding Additional Nodes

When one node isn’t sufficient, adding extra nodes is straightforward. Use a join command to connect new nodes to your existing cluster. Here, the variable AGENT_IP represents the IP address of the machine you’re adding as a node. Clearly specifying this tells your K3s cluster exactly where to connect the new node. Ensure you specify the server’s IP and match the K3s version across nodes for seamless integration:

export AGENT_IP=192.168.1.12
k3sup join --ip $AGENT_IP --user youruser --server-ip $MASTER_IP --k3s-channel v1.28

Your K3s cluster is now ready to scale alongside your needs.

Deploying your first app

Deploying something as straightforward as an NGINX web server on K3s is incredibly simple:

kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --type=LoadBalancer --port=80

Confirm your app deployment with:

kubectl get service

Congratulations! You’ve successfully deployed your first lightweight app on K3s.

Fun and practical uses for your K3s cluster

K3s isn’t just practical it’s also enjoyable. Here are some quick projects to build your confidence:

Simple Web Server: Host your static website using NGINX or Apache, easy and ideal for beginners.
Personal Wiki: Deploy Wiki.js to take notes or document projects, quickly grasping persistent storage essentials.
Development Environment: Create a small-scale development environment by combining a backend service with MySQL, mastering multi-container management.

These activities provide practical skills while leveraging your new K3s setup.

Embracing the joy of simplicity

K3s beautifully demonstrates that true power can reside in simplicity. It captures Kubernetes’s essential spirit without overwhelming you with unnecessary complexity. Instead of dealing with an extensive toolkit, K3s offers just the right components, intuitive, clear, and thoughtfully chosen to keep you creative and productive. Whether you’re tinkering at home, deploying services on minimal hardware, or exploring container orchestration basics, K3s ensures you spend more time building and less time troubleshooting. This is simplicity at its finest, a gentle reminder that great technology doesn’t need to be intimidating; it just needs to be thoughtfully designed and easy to enjoy.

Let’s chat about something interesting in the Kubernetes world called KCP. What is it? Well, KCP stands for Kubernetes-like Control Plane. The neat trick here is that it lets you use the familiar Kubernetes way of managing things (the API) without needing a whole, traditional Kubernetes cluster humming away. We’ll unpack what KCP is, see how it stacks up against regular Kubernetes, and glance at some other tools doing similar jobs.

So what is KCP then

At its heart, KCP is an open-source project giving you a control center, or ‘control plane’, that speaks the Kubernetes language. Its big idea is to help manage applications that might be spread across different clusters or environments.

Now, think about standard Kubernetes. It usually does two jobs: it’s the ‘brain’ figuring out what needs to run where (that’s the control plane), and it also manages the ‘muscles’, the actual computers (nodes) running your applications (that’s the data plane). KCP is different because it focuses only on being the brain. It doesn’t directly manage the worker nodes or pods doing the heavy lifting.

Why is this separation useful? It lets people building platforms or Software-as-a-Service (SaaS) products use the Kubernetes tools and methods they already like, but without the extra work and cost of running all the underlying cluster infrastructure themselves.

Think of it like this: KCP is kind of like a super-smart universal remote control. One remote can manage your TV, your sound system, maybe even your streaming box, right? KCP is similar, it can send commands (API calls) to lots of different Kubernetes setups or other services, telling them what to do without being physically part of any single one. It orchestrates things from a central point.

A couple of key KCP ideas

Workspaces: KCP introduces something called ‘workspaces’. You can think of these as separate, isolated booths within the main KCP control center. Each workspace acts almost like its own independent Kubernetes cluster. This is fantastic for letting different teams or projects work side by side without bumping into each other or messing up each other’s configurations. It’s like giving everyone their own sandbox in the same playground.
Speaks Kubernetes: Because KCP uses the standard Kubernetes APIs, you can talk to it using the tools you probably already use, like kubectl. This means developers don’t have to learn a whole new set of commands. They can manage their applications across various places using the same skills and configurations.

How KCP is not quite Kubernetes

While KCP borrows the language of Kubernetes, it functions quite differently.

Just The Control Part: As we mentioned, Kubernetes is usually both the manager and the workforce rolled into one. It orchestrates containers and runs them on nodes. KCP steps back and says, “I’ll just be the manager.” It handles the orchestration logic but leaves the actual running of applications to other places.
Built For Sharing: KCP was designed from the ground up to handle lots of different users or teams safely (that’s multi-tenancy). You can carve out many ‘logical’ clusters inside a single KCP instance. Each team gets their isolated space without needing completely separate, resource-hungry Kubernetes clusters for everyone.
Doesn’t Care About The Hardware: Regular Kubernetes needs a bunch of servers (physical or virtual nodes) to operate. KCP cuts the cord between the control brain and the underlying hardware. It can manage resources across different clouds or data centers without being tied to specific machines.

Imagine a big company with teams scattered everywhere, each needing their own Kubernetes environment. The traditional approach might involve spinning up dozens of individual clusters, complex, costly, and hard to manage consistently. KCP offers a different path: create multiple logical workspaces within one shared KCP control plane. It simplifies management and cuts down on wasted resources.

What are the other options

KCP is cool, but it’s not the only tool for exploring this space. Here are a few others:

Kubernetes Federation (Kubefed): Kubefed is also about managing multiple clusters from one spot, helping you spread applications across them. The main difference is that Kubefed generally assumes you already have multiple full Kubernetes clusters running, and it works to keep resources synced between them.
OpenShift: This is Red Hat’s big, feature-packed Kubernetes platform aimed at enterprises. It bundles in developer tools, build pipelines, and more. It has a powerful control plane, but it’s usually tightly integrated with its own specific data plane and infrastructure, unlike KCP’s more detached approach.
Crossplane: Crossplane takes Kubernetes concepts and stretches them to manage more than just containers. It lets you use Kubernetes-style APIs to control external resources like cloud databases, storage buckets, or virtual networks. If your goal is to manage both your apps and your cloud infrastructure using Kubernetes patterns, Crossplane is worth a look.

So, if you need to manage cloud services alongside your apps via Kubernetes APIs, Crossplane might be your tool. But if you’re after a streamlined, scalable control plane primarily for orchestrating applications across many teams or environments without directly managing the worker nodes, KCP presents a compelling case.

So what’s the big picture?

We’ve taken a little journey through KCP, exploring what makes it tick. The clever idea at its core is splitting things up, separating the Kubernetes ‘brain’ (the control plane that makes decisions) from the ‘muscles’ (the data plane where applications actually run). It’s like having that universal remote that knows how to talk to everything without being the TV or the soundbar itself.

Why does this matter? Well, pulling apart these pieces brings some real advantages to the table. It makes KCP naturally suited for situations where you have lots of different teams or applications needing their own space, without the cost and complexity of firing up separate, full-blown Kubernetes clusters for everyone. That multi-tenancy aspect is a big deal. Plus, detaching the control plane from the underlying hardware offers a lot of flexibility; you’re not tied to managing specific nodes just to get that Kubernetes API goodness.

For people building internal platforms, creating SaaS offerings, or generally trying to wrangle application management across diverse environments, KCP presents a genuinely different angle. It lets you keep using the Kubernetes patterns and tools many teams are comfortable with, but potentially in a much lighter, more scalable, and efficient way, especially when you don’t need or want to manage the full cluster stack directly.

Of course, KCP is still a relatively new player, and the landscape of cloud-native tools is always shifting. But it offers a compelling vision for how control planes might evolve, focusing purely on orchestration and API management at scale. It’s a fascinating example of rethinking familiar patterns to solve modern challenges and certainly a project worth keeping an eye on as it develops.

Kubernetes made simple with K3s