Kubernetes

Kubernetes is an open source platform for deploying, scaling and managing container applications. As an orchestrator, he manages the operation of the container on the cluster as well as the workload, in order to ensure the constant operation of the application in the event of a single node.

Not so long ago, we used and developed monolithic applications with huge database silos that grew with new features until they turned into huge and difficult-to-manage giants.

With the increasing digitalization of business, the need for new functionalities on applications grew with the acceleration of the business average. We started to get to a state where after we finish some new functionality it is already obsolete. In some cases, it happens that there is something for free, which makes it better.

Today, a growing number of developers, architects and DevOps experts are of the opinion that it is better to use microservices, rather than giant monilith, to speed up delivery and create space for technological innovation. Using a microservice-based architecture usually divides an application into at least two applications: front-edn and back-edn-api.

When organizations decide on a microservice architecture, the question arises: In what environment is it best to run microservices? The answer to this question is Docker, a tool that has become the standard for containers today.

Kubernetes?

Kubernetes is open source software for deploying, scaling, and managing container applications. As an orchestrator, it manages the operation of the container on the cluster, it also manages the workload, to ensure the constant operation of the application in the event of a single container being unlocked.

In 2014, Google opened the project to the open source community. Kuberenetes works based on decades of experience Google has in working with containers with constant community innovation.

Kubernetes is the first project of the Cloud Native Cloud Foundation (CNCF), which brings together the world’s leading technology manufacturers in order to adequately manage the project. The importance of this is also shown by the fact that Kubernetes is the fastest growing open source project in history.

To better understand why Kubernetes is such an important project, backed by the world’s largest corporations. This is evidenced by the fact that IBM set aside 33.4 billion for the purchase of Red Hat and OpenShift based on Kubernetes.

We need to understand the evolution of the consumption of computer resources in the last fifteen years.

Traditional deployment

Organizations ran applications on physical servers. There was no way with this approach to clearly define resource boundaries for applications. This has caused problems in the operation of applications over time as organizations have grown. It happened that one application took up more resources and thus prevented the other application from accessing resources for uninterrupted operation. The solution was to run different applications on different physical servers, but even that did not lead to relief. It has led to more expensive maintenance of a bunch of physical half-used servers.

Virtualization

As a way to overcome the problem of non-optimized use of hardware resources came the era of virtualization of a physical server on multiple virtual machines (VM). Virtualization allows us to run multiple virtual machines (smaller copies of a physical server) on the CPU of a single physical server. Virtualization allows us to run applications in isolated virtual machines and thus gain better security while retaining the ability to store resources as needed by the application. Each VM runs its components at the operating system level on virtualized hardware.

Containers

Containers are similar to virtual machines (VMs), but have more relaxed isolation for sharing the operating system (OS) between applications. Therefore, containers are considered lightweight packages with almost the same characteristics as VMs. Similar to a VM, storage has its own file system, CPU, memory and much more needed to work and connect to other parts of the application or the platform itself. Because they have a separate connection from the infrastructure, they can be moved between cloud environments, as needed, and business challenges.

Containers have become floodplain because they provide additional benefits such as:

creating agile applications using lighter packages and scheduling modelscontinuous development (continiuse developmnet)consistency between the development environment and the production environmentreducing the time spent on infrastructure maintenanceresource isolation and the possibility of predictive allocation in accordance with the load

Why do we need Cubernetes?

Containers are a very good way to pack and deploy your applications. In your development environment, you need to manage the containers that run applications and ensure there are no downtimes. For example, if a container stops working, another one should be started. Would it be easier if he managed the system with such behavior?

Kubernetes provides you with an environment for the elastic launch of distributed systems or clusters of your containers. It takes care of the scaling and connections of your application with other applications, provides predefined implementation patterns or allocation to multiple nodes.

Kubernetes consists of:

Pod – the smallest unit in Kubernetes.Master nod – the central unit in the cluster.Worker node (minion): – execute the workload by the Master node

The floor is the smallest unit in Cubernetes. Pod is synonymous with peas containing peas. Each floor can contain one or more containers depending on the load. Containers located in the same Pod share the host, which means they share the same IP address and ports. Represents a running process in a cluster.

Master node – launches multiple services responsible for cluster health, replication, availability and end points, Kubernetes API, interaction with the part in charge of infrastructure (IaaS) whether it is a private or public cloud environment.

Worker node (minion): started by the Kubernetes agent who is responsible for launching the Pod container via Docker. It takes care of the configuration and the amount of space required for the data warehouse. Performed monitoring and checking the load status of the rest of the system.