Infrastructure

A clear overview of your containers? Discover everything about Kubernetes.

As a company, you encounter an overwhelming amount of data and applications. Many of these applications are now delivered in container form or are internally developed through a CI/CD pipeline, resulting in containers as output. Obviously, you want to be able to keep these containers up and running without any downtime. That is why there is a significant need for a platform that manages and facilitates the maintenance of these containers. This is where Kubernetes comes into play.

Read our blog post and explore what Kubernetes exactly is, how container technology works once again, what the difference is between containers and VMs, and why you should choose Kubernetes.

A brief overview of containers and microservices

Before delving deeper into Kubernetes, it is useful to briefly address terms like ‘containers’ and ‘microservices’. We believe this information is necessary to grasp the larger Kubernetes context.

Microservices are related to software design, concerning how software functions are programmed. Large blocks of software are divided into many small components. Each component is responsible for a specific function of the software. So the software is constructed based on mini-applications that communicate through APIs. These mini-applications can be implemented and adapted quickly, easily moved between different environments, and scaled efficiently. All of this without causing any disruptions or noticeable changes to end-users. For example, an application can update a specific function without affecting other app functions, while the end-user won’t even notice.

Applications today are often built based on these microservices, which is why containers have gained importance. The term ‘container’ refers to the way microservices are ‘packed’. Basically a container is an infrastructure for packing, deploying, and moving applications. All the things necessary for the application to run (for example: the code, configuration files, libraries, etc.) is included in the container along with the software itself. This approach eliminates the need to modify the software to adapt it to the environment in which it will run. Using containers provides a lot of flexibility, portability, and scalability.

Why use containers instead of VMs?

When handling large and flexible workloads as a company, virtual machines (VMs) fall short. VMs are bulky because they include a complete operating system alongside the application. They consume more storage space, CPU power, and memory of the physical server. This is no longer the case with containers. Containers share the host’s operating system. Therefore, there’s no need to incorporate the entire operating system into a new VM and manage it separately. A container only includes the components necessary to keep an application running smoothly. This makes containers much more mobile, flexible, and scalable.

So, what exactly is kubernetes?

Kubernetes is an open-source solution that automates the deployment, scaling, and management of containers. This system is designed to manage and organize large groups of containers while keeping a clear overview.

Given the increasing use of container technology, a solution like Kubernetes is invaluable (despite its technical complexity). It’s an intelligent solution that allocates resources to containers and handles load balancing. When traffic to a specific container becomes too high, Kubernetes automatically redistributes and redirects the traffic to another container. This approach preserves the stability of the application.

Moreover, Kubernetes restarts stalled applications on another node within the cluster (failover), so that applications can continue to run smoothly. It can also easily scale up or down according to your application’s needs. As you can see, all these functionalities ensure efficient resource utilization, leading to financial benefits.

Kubernetes and its various components

Kubernetes is a system that runs workloads enclosed in containers. These containers are placed in pods, which then run on worker nodes. The worker nodes are managed by the master node. Not sure what all this means? We’ll provide you with some additional explanations:

Master Node:
This node monitors and manages the cluster infrastructure (composed of various worker nodes). It doesn’t manage individual containers separately. The master node supervises the different worker nodes. You set criteria in advance for when and how containers should start or stop. Based on these criteria, the master node initiates and halts additional containers.

Worker Node:
A worker node is a component of the Kubernetes cluster that hosts pods. It can be either a virtual or physical machine, depending on the cluster. Worker nodes are used to run containerized applications.

Cluster:
A collection of nodes on which containerized applications run, managed by Kubernetes.

Pod:
A pod is the smallest unit in the Kubernetes context. It bundles closely interacting containers that share storage and network resources. Pods are ephemeral components of Kubernetes. They can be created and destroyed based on your cluster’s requirements. Pods can communicate with each other.

Service:
Pods are designed to be ephemeral, with a non-permanent nature. The ‘Service’ function assigns permanent IP addresses to pods. When a pod crashes, its IP address remains unchanged upon restart. Additionally, a service can provide load balancing between different pods.

Network Provider:
The network provider ensures smooth traffic management between applications within the cluster, as well as traffic from outside the cluster. Calico and Flannel are the most commonly used container network interfaces for both containers and virtual machines.

Ingress:
‘Ingress’ is an Application Programming Interface object containing rules for directing external user traffic within the cluster.

Ingress Controller:
The ingress controller is responsible for distributing and redirecting incoming traffic to the relevant microservice within the Kubernetes cluster based on the aforementioned ingress rules. This traffic can be HTTP or HTTPS.

Config Map:
This Kubernetes object enables customization within a Kubernetes image. This allows you to deploy the same application for different clients, each with specific configurations tailored to their needs.

Secret:
A secure Kubernetes object containing sensitive data such as passwords, tokens, security keys. There are different types of ‘secrets’. When setting up a ‘secret’, you specify its type. Kubernetes secrets are similar to ConfigMaps within Kubernetes, but they are intended for sensitive information.

Volume:
Different types of volumes exist within Kubernetes: ephemeral, persistent, shared, and projected volumes. A pod can use multiple types simultaneously. Ephemeral volumes exist for the lifespan of a pod, while persistent volumes persist beyond the pod’s lifetime. When a pod ceases to exist, Kubernetes removes its ephemeral volumes but retains the persistent ones. A volume is a directory accessible to the containers within a pod.

Deployment:
When deploying an application, you create a deployment file. This file outlines the number of pods, services, etc., required to deploy an application. You can predefine the minimum and maximum number of pods (as well as the amount of resources that can be used), enabling automatic scaling up and down.

Why choose Kubernetes?

Containers are an effective way to pack and deploy your applications. It’s crucial to ensure there’s no downtime in a production environment. When a container crashes, you want it to automatically restart, right?

Automation
Kubernetes is a system heavily focused on automation, which is one of its biggest advantages. The human factor is eliminated, and an intelligent solution is established. If a container crashes, Kubernetes automatically starts a new one. Similarly, when traffic becomes too high, Kubernetes automatically redirects it to other containers.

Unified language
Kubernetes utilizes ‘declarative configuration’. This means that a single language is used in its setup, and all specialists use the same programming language. This simplifies the management of containers and applications, reducing the time and knowledge required.

Flexibility, efficiency and scalability
The fact that Kubernetes automates many tasks allows this solution to be flexible, efficient, and scalable. The solution will automatically scale as needed, depending on the traffic to and from the containers. This automation also serves as a response to the impact issues can have on your system. Kubernetes individually verifies each component and then automatically corrects it. This reduces the impact since problems are quickly detected and rectified. This, in turn, positively affects the availability of your system and its performance level.

Portability
Containers possess what they need to operate and are isolated from their infrastructure, making them highly portable. This makes it easy to relocate workloads.

In addition to the numerous benefits of this solution, we are aware of its drawbacks as well. Without the appropriate technical knowledge, it can become a maze very quickly. The Nutanix-Kubernetes-Engine (NKE) can be an enormous asset for managing the Kubernetes environment. Learn more about it in our blogpost.

Syntory's Kubernetes-in-a-box Solution:

Given that the Nutanix-Kubernetes-Engine is not the only solution and setting up the environment can be complex, we offer Kubernetes as a solution: Kubernetes-in-a-box. Download our one-pager and discover all about this all-in-one Kubernetes solution!

Do you have any questions? Feel free to reach out via the form below. We’re more than happy to clarify any uncertainties and explore the possibilities with you!