Kubernetes have made developer’s life easy and are a continuously growing platform. It is software that helps the user to manage the application by automating the process. It makes use of containers to control how applications are deployed on servers and how they interact with one another. It also makes sure that the applications are available for the users 24/7 and the developers don’t have to worry about managing the application instead just focus on the development. It makes sure that in any kind of cyber attack or application failure, the backup is always ready and can handle the traffic without any disruption. It standardizes the way users interact with the applications and different components with the help of Kubernetes API.
Learning about Kubernetes is not an easy task because it has several features that you would need to learn in detail. If you are a beginner and want to learn about Kubernetes, then the learning path for you will cover everything from basic concepts and components to advanced skills of Kubernetes that will be needed for centralization.
The application and its deployment, the whole process starts from the containers. The different parts of a single application are managed in different containers and that enables us to create different repetitive environments so all the features are looked at and function in a similar way. Kubernetes APIs manage the containers that hold the application but are not very good at managing a greater number of containers. So for that, things like scheduling, load balancing, and distribution of workload are used. Because of all these problems, orchestration is the ability to manage all the container instances. Kubernetes came in to solve all these problems in the handling of applications.
Kubernetes works with the help of clusters that are connected to work as a single unit and run the applications. Instead of having different clusters on different machines, it gathers all of them and allows the user to deploy the centralized applications. For the deployment of the applications, they need to be centralized which means that they are packaged in a way that there are no individual hosts for them. With the help of Kubernetes, the applications can be automated, and scheduling of clusters of applications that if any case one of them fails, the other one should be always ready as a backup. This feature makes the application 24/7 available for the users on application without any disruption.
There are two main resources of Kubernetes which are nodes and control plane. Nodes are the machine that acts as the workers in the Kubernetes cluster. All the actions in the clusters are managed and automated because of these nodes. Every node communicates with the control plane with the help of an agent which is also called Kuberlet. Since the control plane manages all the traffic in the cluster, so it should have at least four nodes so that if one goes down, there should always be more at the backup. because if not then the redundancy is compromised. The control plane is responsible for the activities of the cluster which means all the scheduling, maintaining, managing applications, scaling of applications, and keeping all the pods updated of the application are done by the control plane.
Once the Kubernetes cluster is ready and running, then the decentralized applications can be deployed on it. For deploying the application, you need to create a deploying configuration first which explains how the instances will be created and updated for the application that has to be deployed. Different nodes are set up to automate to manage the operations of the application. Meanwhile, the control plane schedules different instances of the application to run the application on different nodes in the cluster. The maintenance of the application and making it go live again in any kind of failure is provided by it.
Two of the very important components of Kubernetes are pods and nodes. We will discuss where and how they both are used in detail in this section.
Pods are used to host the application that is deployed on Kubernetes and they can hold more than one application at a time. The application containers and also some shared sources like shared storage between containers, networking, etc. Pods are Kubernetes’s units that have containers of applications inside them. Each pod is connected to nodes where it is scheduled. Different pods have the same application and contain the same containers so they are identical to each other, in case of any failure of a node, a different node available in the cluster is scheduled with the identical which also has the same application. The pod stays with the node until it is deliberately deleted.
A node is a worker machine that is programmed to work automatically and handle traffic. It can be both physical or virtual depending on the complexity and size of the cluster. Nodes are controlled by the control place and it assigns the workload to the nodes in the cluster whereas each node can have multiple nodes. Scheduling of nodes is done by the control plane depending on the availability of the nodes. Every node consists of a Kubelet, an agent which is responsible for the communication between nodes and control to collaborate and manage the pods and containers in a cluster of an application.
Different Kubectl commands are used to get information about the already deployed applications. After deploying applications, you can check the cluster status by different commands. Some of the most used commands of Kebectl are Kubectl get, Kubectl describe, Kubectl log, and Kubectl exec. These commands are used to essentially know the status of your application that how they are running and what their configurations are. There is currently some software available from which you don’t have to use the terminal to use the commands but instead use a web which has a very easy UI so you can easily understand it. IT is a very good thing for non-developers to understand the status of the applications.
When the application is deployed on Kubernetes, one pod is created for it to manage it but with time the traffic on the application increases, and then it needs to scale up so it can handle the traffic. This problem is overcome by creating multiple pods just like the first one. The number of pods is increased according to the requirement to the desired state of the pods. Having multiple identical pods will distribute the traffic between the pods so that the workload is not only on one pod. Autoscaling is also offered by Kubernetes as a service in which it increases the pods by analyzing the increasing traffic on the application. The pods are managed so that only available pods get the traffic. The pods have a life cycle and they might go down after some time, so for that backup pods are always available. All the pods are updated when there is an update in the application and there is no downtime for the users using it.
To keep the applications up to date, the developer needs to perform multiple deployments in a day so that all the new updates are deployed regularly. Normally, it is not allowed to deploy multiple times in a day but Kubernetes provides the developers with the facility that they can push the codes multiple times a day. On the other hand, users don’t want any disruption while they are using the application so they expect no downtime. When the application is updated, the new pods are scheduled with different nodes without any downtime.
The number of pods that are expected to be unavailable because of the update, is replaced with the maximum number of new pods to replace them. When the application is scaled up due to the increased traffic during all these new updates, the availability of the application is not affected. Keeping applications updated include accuracy and updating application with zero downtime, going back to older versions of pods, and changing the container of an application.
Learning Kubernetes is a long way and almost never ending. Learning about the basic concepts to making the projects to mastering there is a lot to learn. The best way to learn Kubernetes is through hands-on practice. There are multiple courses, training, and certifications available that are designed to introduce beginners to the fundamentals of Kubernetes and a broader introduction to Kubernetes. OmniCloud provides training through different courses to help you train your Kubernetes skills. At the current time, almost all businesses are software dependent and are moving towards Kubernetes to make the companies cloud native so that they can grow without any software hindrance. Kubernetes has emerged as a building solution for all businesses as a result of continuous research and development.
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