📍 Introduction

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. It was originally developed by Google and is now maintained by the Cloud Native Computing Foundation (CNCF).

Kubernetes allows you to deploy and manage containerized applications across a cluster of nodes. It provides a powerful set of features for container orchestration, such as automatic scaling, self-healing, and rolling updates. With Kubernetes, you can easily manage containerized applications, monitor their performance, and ensure high availability.

Kubernetes uses a declarative approach to deployment, which means that you define the desired state of your application, and Kubernetes will automatically ensure that it is running in that state. Kubernetes also provides a rich set of APIs, allowing you to integrate it with other tools and services in your environment.

🔹Kubernetes Architecture

The architecture of Kubernetes is designed to support the deployment and management of containerized applications at scale. At a high level, Kubernetes architecture consists of three main components: the master node, worker nodes, and etcd cluster.

1. Master Node: The master node is responsible for managing the cluster and its components. It acts as the control plane for the Kubernetes environment and makes decisions about how to schedule and manage containers. The master node consists of several components, including:

• API server: The API server exposes the Kubernetes API, which is used by other components to communicate with the Kubernetes cluster.

• etcd: etcd is a distributed key-value store that is used to store the configuration data for the cluster.

• Controller manager: The controller manager is responsible for managing various controllers that oversee the state of objects in the cluster.

• Scheduler: The scheduler is responsible for determining where to place containers on the worker nodes.

1. Worker Nodes: Worker nodes are responsible for running containers and providing the compute resources needed by the containers. Each worker node has the following components:

• kubelet: The kubelet is the primary agent that runs on each worker node and communicates with the Kubernetes API server to receive instructions on how to manage containers on the node.

• kube-proxy: The kube-proxy is a network proxy that runs on each worker node and handles network communication between containers.

1. etcd Cluster: The etcd cluster is a distributed key-value store that stores the configuration data for the cluster. It is used by the master node to store information about the state of the cluster, including information about the containers, services, and other objects.

🔹Kubernetes Components

These components work together to provide a powerful platform for deploying and managing containerized applications. By leveraging the capabilities of these components, Kubernetes enables you to create scalable and resilient applications that can adapt to changing needs. The following are the components of Kubernetes.

• Pod: A pod is the smallest deployable unit in Kubernetes. It is a logical host for one or more containers and provides a way to group containers that need to work together. Pods are created and managed by Kubernetes and can be scaled up or down depending on the application's needs.

• Service: A service is an abstraction that defines a logical set of pods and a policy by which to access them. Services provide a stable IP address and DNS name that can be used to access a group of pods, regardless of which worker node they are running on.

• Deployment: A deployment is a higher-level abstraction that manages the deployment of a set of replicas of a pod. Deployments enable you to roll out updates to your application in a controlled manner, ensuring that your application remains available during the update process.

• ReplicaSet: A ReplicaSet is responsible for ensuring that a specified number of replicas of a pod are running at any given time. If a pod fails, the ReplicaSet automatically replaces it with a new pod to maintain the desired number of replicas.

• StatefulSet: A StatefulSet is similar to a ReplicaSet, but it provides guarantees about the order in which pods are created and the stable network identities that are assigned to them. StatefulSets are used for stateful applications that require unique network identities and stable storage.

• ConfigMap: A ConfigMap is used to store configuration data that can be used by containers in a pod. ConfigMaps can be used to store environment variables, command-line arguments, and configuration files.

• Secret: A Secret is used to store sensitive data, such as passwords or API keys, that should not be exposed in plain text. Secrets can be mounted as files or environment variables in a pod.

🔹Kubernetes Installation and Configuration

Installing and configuring Kubernetes can be a complex process, but there are several tools and resources available to help simplify the process.

You can follow the below documentation to install Kubernetes on Ubuntu OS.

https://www.itsgeekhead.com/tuts/kubernetes-126-ubuntu-2204.txt

📍 Conclusion

Kubernetes is a powerful tool for deploying and managing containerized applications. Its architecture and components provide a flexible and scalable platform for running applications in a variety of environments. However, installing and configuring Kubernetes can be a complex process that requires careful planning and attention to detail. By choosing the right installation method, setting up the master and worker nodes, configuring networking and storage, and securing the cluster, you can create a Kubernetes environment that meets the needs of your application. With Kubernetes, you can take advantage of the benefits of containerization and orchestration, such as faster deployment times, increased scalability, and improved resource utilization, to deliver high-quality services and applications to your users.