How to build a Kubernetes cluster with the Kubernetes API

Kubernetes is one of the many container orchestration tools readily available on the software market. It provides vital features optimized for the management of containerized applications. The container orchestration may remind you of the big orchestra with the musical instruments from the “Bugs Bunny'' cartoon. Bugs is the concertmasterPerson leading an orchestra. playing the orchestra. This shows that any container orchestration platform, such as Kubernetes (ConcertMaster), manages and overlooks all the tedious processes for deploying and scaling containerized applications. Now Kubernetes makes the complexity easier through its capabilities, which are stated below:

• Automated deployment and scaling of containers

• Service discovery and load balancing systems

• Automated scaling, self-healing, and rollbacks

• Facilitated configuration and secret management 

• Enabled storage orchestration and life cycle management

• Flexible deployment environments

What is the Kubernetes cluster?

Now, the architecture of Kubernetes is based on a hierarchical system. The first thing the user calls is the API server, which is in the main node and is referred to as the control planeResponsible for managing and orchestrating the cluster's components and ensuring the desired state of the system.. This node then connects to all the other nodes, also known as the worker nodes, which answer to the managing node. When we deploy Kubernetes, we have to deploy a cluster. The deployed cluster has multiple worker nodes that are answerable to the managing node. These nodes contain the containerized applications that we have to run. 

The clusters we run can contain multiple manager nodes, consequently having more worker nodes. We need these nodes to manage the task at hand efficiently. Moreover, we have two methods for using Kubernetes services:

• Using cloud-provided managed Kubernetes services

• Using a self-managed Kubernetes cluster

When we use the cloud-provided managed Kubernetes services from the cloud provider's APIs (e.g. ‘AWS’), we do not have direct access to manage the control plane on the managing nodes. This is because the cloud provider takes on all the management and hides what's under the hood. On the other hand, if we opt for self-managed Kubernetes services, we end up working on minute details. However, the most important advantage we have over the other option is the possibility to customize the cluster’s configuration and management. Getting more control over the cluster breeds more responsibilities to maintain the cluster, which are stated below:

• Infrastructure provisioning

• Cluster installation

• Worker node configuration

• Networking setup

• Security

• Resource management

• Application deployment

• Monitoring and logging

• Upgrades and maintenance

• Backup and disaster recovery

• Troubleshooting

Let's look at how we can build a self-managed Kubernetes cluster.

Building a Kubernetes cluster with Kubernetes API

When talking about the Kubernetes API, we have to first understand what an API is, why we use it, and what the Kubernetes API is used for. APIs are a set of tools and protocols that help different software components interact and exchange information. There are different types of APIs, including web APIs, database APIs, etc. 

Kubernetes APIs enable users to interact with the management of the clusters through different methods of communication, including:

• Kubectl

• Client libraries

• REST APIs

As we can see, APIs only help in the interaction between software components and do not create things such as Kubernetes clusters. Kubernetes APIs enable us to manage and collaborate on different Kubernetes cluster aspects.

Now, we’ll give an overview of the steps needed to build a Kubernetes cluster.

• Provisioning infrastructure: This refers to arranging the basic infrastructure for the cluster to reside upon. This includes allocating computing and storage resources (such as virtual machines and physical servers), setting up the network infrastructure and the container runtime, and implementing key security measures.   

• Configuring control plane: This refers to the manual setup for the control plane, where some of the most critical components reside. 

• Configuring worker nodes: This refers to joining the worker nodes to the managing node, which is essential to connecting to the control plane.

• Configuring network architecture: This setup is crucial in establishing a cluster, as all the communication between components is done through the network. 

• Configuring security mechanisms: These authentication and authorization mechanisms ensure the security of the newly created Kubernetes cluster.

Let's take a short quiz related to the concept of Kubernetes.

Overview

This overview shows that following these steps could help you create a cluster. After the creation of the Kubernetes cluster, the Kubernetes API comes into play. Kubectl or client libraries can be used to interact in a user-friendly way with the Kubernetes API to manage and perform various tasks on the cluster.