Understanding Common Kubernetes Terms

11 November 2021 by Katy Ryder

Kubernetes is quickly becoming the go-to tech for companies looking to run containerized applications. The big downside? Kubernetes is also pretty complicated. Even those in the know still need to keep up with the constantly changing, dynamic environment. If you’re looking at implementing Kubernetes for your team, you’ll need to brush up on some common Kubernetes terms. 

Read on to learn more about Kubernetes and to develop a firm understanding of common Kubernetes terminology. Hopefully, by the end of this article, you’ll have a better grasp of what Kubernetes is and what it can do for you and your business.

How complicated is Kubernetes terminology?

Kubernetes (K8s) is the evolution of container technology. At its core, containers are pretty basic. They offer a lot in terms of operational functionality but, by themselves, don’t have the kind of enterprise power you’d expect from a robust cloud-based application system. That’s where K8s come in.

It's up to K8s to perform a lot of the tech-heavy leg work. When you have a lot of containers, you get a ton of back and forth chatter that can bog systems down and become quite confusing. K8s orchestrates all these containers in a way that puts several key best practices at the front of operations:

  • Diversity
  • Resilience
  • Scalability
  • Security

Kubernetes breaks down this world into nodes and then wraps those nodes together into pods. All across this chain are methods of communication with the master node and even the etcd. Taken together, you get what we call a cluster.

If you don’t know what we’re talking about yet, don’t worry, that’s the point. All of this Kubernetes terminology is probably new to you if you aren't already familiar with K8s. We’ll walk you through what you need to know.

Kubernetes terms explained: The basics

To get you started on the right foot, we’ve compiled a list of some Kubernetes basic terms. This certainly isn’t the end all be all of a K8s dictionary, but it should give you enough to get started on your K8s journey. If you need a bit more of a deep dive, check out our glossary of Kubernetes terminology.

Container

A container is simply a structure that can store and run an application. This is like the basic lego brick of the Kubernetes world. Around 2000 the world was introduced to the software container. Originally, containers were an alternative to Virtual Machines (VMs). Nowadays, though, they're the go-to standard for virtualization.

Simply put, a container takes only the necessary application components of an operating system (OS) and wraps it all up in a neat and usable package, separate from any actual OS. Using containers, you can strip away virtually 99% of the OS — giving users access to the application in a barebones approach.

Pod

A Pod is one of the simplest of all the K8s components. Well, simple is a relative term, especially when talking about K8s. Regardless, Pods represent a set of running containers set in a cluster. Typically, a pod will run a single primary container — but that’s not always the case.

Additionally, a pod can run an optional sidecar container that will add other features. One additional feature you might run into is logging. The deployment is in charge of managing Pods.

Node

A node is essentially a worker machine in Kubernetes. It can be either a VM or a physical machine, depending on the cluster. The workload of the node is run by putting containers into pods. These pods run on nodes. Fun fact: In the early days of K8s, nodes were called minions.

In each individual cluster, you’ll usually be running several nodes at a time. Each node will also carry:

  • Kubelet
  • Kube-proxy
  • Container runtime

You can read more about these three things in our Kubernetes glossary.

Cluster

You’ve got the node, and a GROUP of nodes is a cluster. A cluster is basically a set of worker machines — the nodes — and running containers (those stripped-down apps we touched on earlier). The cluster, and every node and container wrapped up inside, is what Kubernetes is managing.

The worker nodes host the pods that run the application workload. The control plane is in charge of managing the cluster. Within the cluster itself are other components, like the master node, worker nodes and etcd. All of this information pertains to how we manage containerized applications, and it’s worth noting that the worker nodes (the grouped containers) are actually in charge of running apps and managing workloads.

Other terms to know

So, those are some of the basic Kubernetes terms explained, touching mostly on the basic components of Kubernetes architecture. Of course, covering the terminology is only scratching the surface of the Kubernetes ecosphere. To go through it all would require a whole mess of coursework, textbooks, lectures and quizzes. 

Here are just a few other basic terms you may come across:

  • Controller: Controllers are the control loops watching the overall state of the cluster. They make or request changes when needed.
  • Docker: Also known as Docker Engine, this is the software behind the OS-level virtualization in containers. 
  • Etcd: The etcd stores the configuration information for the large distributed system. 
  • Minikube: If you're running a single-node cluster in a VM, you usually use a tool called a minikube.
  • Namespaces: A namespace is essentially a virtual cluster that can provision resources and provide additional scope for pods. It also provides additional qualifications to a resource name.
  • Secret: A secret in K8s is a means of storing sensitive information. It's a security feature that helps components communicate.
  • Service: Service is the abstract way in which an application is exposed on a set of pods. The service ensures that network traffic is sent to the current set of pods managing the workload.

Doing Kubernetes right with Wayfinder

Even for the most seasoned CKAs, Kubernetes can get confusing. Nevertheless, it makes running cloud application architecture easy to do on a massive scale. Some companies don’t have any other choice than to jump onto the K8s bandwagon.

That’s where Appvia’s Wayfinder comes into play. Our cloud-based platform essentially automates a lot of the background work involved in developing clusters and managing them. We built Wayfinder to work with any team without the need for a resident K8s specialist. So, even if you don’t have the Kubernetes terminology down pat, you can still enjoy the benefits of a K8s. 

If you want to learn more about Wayfinder, and how it can help your team with K8s, make sure to reach out today to get started.

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About the author

Picture of Katy Ryder

Katy Ryder

Content Marketing Manager

I originally hail from Austin, Texas but now call London home. When I’m not crafting content for Appvia, you might run into me at a coffeeshop (there’s always room for one more latte), hiking through Hampstead Heath or snapping street style photographs.

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