Kubernetes Tutorial

Automatic computer upgrades are inconvenient, especially if you're in a hurry. But envision doing it on an organizational scale: it would be a total disaster. People are unable to work when the system is down.

Developers must be able to upgrade and maintain their company's systems without halting the entire operation. And, as containers grow more popular, development teams will want more efficient ways to control their systems. This is where Kubernetes enters the picture. Here's everything in this Kubernetes tutorial that you require to learn.

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. With Kubernetes, you can easily manage and deploy applications across multiple cloud providers or on-premises infrastructure. In this Kubernetes tutorial, we will cover the basics of containers and container orchestration, Kubernetes architecture, and key components, and how to set up a Kubernetes cluster, deploy an application, and scale it as needed. Whether you're new to Kubernetes or have some experience with it, this Kubernetes tutorial will provide you with a solid understanding of Kubernetes and its capabilities.

So, let's dive into the world of Kubernetes and explore its capabilities!

Kubernetes Tutorial - Table of contents:  What is Kubernetes? Why do we use Kubernetes? Kubernetes basics Features of Kubernetes The architecture of Kubernetes Advantages of using Kubernetes Disadvantages of using Kubernetes Installation and Setup What tasks are performed by Kubernetes?

What is Kubernetes?

Kubernetes is a Google platform-based container management solution. Kubernetes aids with the management of containerized applications in a variety of virtual, physical and cloud environments. Google Kubernetes is a highly adaptable container solution for continuously delivering sophisticated applications on clusters of hundreds of separate machines.

Kubernetes is a free and open-source solution for container deployment. It was initially conceptualized at Google but is now maintained by the Cloud Native Computing Foundation (CNCF). 

Kubernetes has gained popularity because it resolves many issues associated with using containers. Kubernetes makes it simple to launch unlimited container replicas, distribute them among many physical hosts, and configure networking so users can access the service efficiently. 

Docker is where most developers begin their container adventures. While this is a powerful tool, it is somewhat limited and depends on CLI instructions that connect with just one container at a time. Kubernetes provides significantly greater frameworks for designing applications and infrastructure through expressive models that can be freely created.

 

Why do we use Kubernetes?

Although container APIs are very well tailored for handling individual containers, they need to be more robust for managing applications that may consist of hundreds of units scattered over many hosts. Containers must be controlled and linked to the outside world for programming, task scheduling, and distribution. This is where a continuous integration technology like Kubernetes comes in handy.

Kubernetes manages workloads and schedules containers on a computational network to ensure they function as the client expects. Rather than loading on activities as an addition, Kubernetes integrates software engineering and operations through strategy. Kubernetes allows an order-of-magnitude increment in the operability of modern software systems by adopting expressive, infrastructure-agnostic structures to specify how applications are created, interact, and maintained.

Want to acquire industry skills and gain complete knowledge of Kubernetes? Enroll in Instructor-Led live Kubernetes Training to become Job Ready!

 

Kubernetes Basics:

There are a few basic terminologies used in Kubernetes that one must be aware of. They are as follows:

1) Cluster: A network of nodes that execute containerized applications. Kubernetes is used to manage the set and everything inside it. A set consists of a master node and some subordinate nodes. While the control plane attempts to keep the cluster in the intended condition, the worker nodes are responsible for running the applications and workloads.

2) Master: The master is a set of Kubernetes control panel components. These are utilized for each cluster choice.

3) Node: In Kubernetes, a node is a worker computer; a workload is executed by placing containers into pods, which in turn, operate on nodes. Depending on the cluster, a node might either be a virtual or a real machine. Each set will often have numerous nodes, with the Kube-proxy, kubelet, and container runtime installed on each node.

4) Namespace: Namespaces are used to separate distinct types of resources. They minimize name conflicts by limiting the view of your resources. Creating two or more objects with the same name within the same namespace is illegal. If you're in the default namespace, you can't have two Pods named database. Namespaces tackle this by separating resources logically. Without producing a conflict, two namespaces called app-1 and app-2 might each include a Pod-named database. Namespaces are versatile and may be utilized in a variety of ways. You may create a namespace for each task in your cluster. By implementing role-based access control, you may also use namespaces to partition resources across users and teams.

 

Features of Kubernetes: 

Kubernetes provides a robust feature set that encompasses a wide range of capabilities for operating containers and supporting infrastructure:

1) Automated updates, expansion, and rollbacks: Kubernetes builds the requested number of replicas, distributes them to appropriate hardware, and acts accordingly to rearrange your containers if a node fails. You may instantly scale the number of copies on-demand or in reaction to changing conditions such as CPU consumption.

2) Service discovery, bandwidth allocation, and network ingress: Kubernetes offers a comprehensive networking solution that includes internal service exploration and public container availability.

3) Stateless and stateful applications: While Kubernetes began with stateless containers, it now has built-in entities to depict stateful apps. Kubernetes can execute any application.

4) Storage management: Storage management abstracts persistent storage using a uniform interface that works among providers, whether it's in the cloud, on a shared network, or a local file.

5) Declarative state: Kubernetes utilizes object manifestations in the YAML file system to declare the state you wish to build in your cluster. Using a manifest directs Kubernetes to convert the group to the desired shape proactively. You don't have to make the changes you wish to see manually.

6) Made adaptable for various work environments: Kubernetes may be utilized in multiple contexts, including the cloud, the edge, and on your developer desktop. There are several distributions available to suit various use scenarios. Major cloud companies such as AWS and Google Cloud provide administered Kubernetes services, while solitary distributions such as Minikube and K3s are ideal for local usage.

 

The Architecture of Kubernetes:

Kubernetes' command-line interface is known as kubectl. Its purpose is to administer clusters and to communicate well with the Kubernetes API server. The API server then inserts or eliminates containers in that particular cluster to ensure that the expected and actual states match.

The fundamental Kubernetes process is as follows: 

1. An administrator specifies the intended state of an app and then stores it in the manifest file.
2. Using a Common Infrastructure of language or User Interface, this file is transmitted to the Kubernetes API Server.
3. Kubernetes keep this file in a database known as the Key-Value Store.
4. It then applies the required state to all of the cluster's applications.
5. The elements are then monitored continuously by Kubernetes to ensure that they are in the desired shape.

 

Advantages of using Kubernetes:

Kubernetes is a sophisticated solution that allows you to execute applications on a vast scale in a cloud environment. It may increase efficiency by making your apps more reliable and efficient.

1) Increased efficiency: Kubernetes facilitates self-healing, saving developers time and drastically lowering the chances of downtime.

2) More stable applications: You can have periodic software upgrades using Kubernetes without downtime.

3) Systems that are prepared for the future: Because Kubernetes prefers decoupled designs, you can grow your software and the people working on it as your strategy develops. It can tolerate tremendous expansion because it was built to support massive systems. Furthermore, many major cloud suppliers support it, giving you more options.

4) Cheaper than the alternatives: It is not appropriate for tiny applications, but for large systems, it is generally the most cost-effective choice since it can automatically grow your activities. It also results in high utilization, which means you don't pay for services you don't want. Most of the resources in the K8s environment are open-source and hence free to use.

 

Disadvantages of using Kubernetes:

Kubernetes has, however, a few limitations as well. Let us quickly have a look at them:

1. The user dashboard should be more friendly and effective.
2. The security of Kubernetes could be more effective.
3. The use of Kubernetes is quite complex and is irrelevant in specific work environments.

Read these latest Kubernetes Interview Questions that help you grab high-paying jobs

 

Installation and Setup:

One can get started with Kubernetes in a variety of ways. This is so because Kubernetes provides a vast range of distributions. This makes it easy to install and set up quickly and time-efficiently. Most people prefer using packaged solutions such as Kind, Minikube, K3s, or MicroK8s.

For this Kubernetes tutorial for Beginners, we will use K3s for enhanced and clear understanding. K3s may be perceived as the most lightweight distribution of Kubernetes. K3s offers a coherent group of all the necessary components of Kubernetes in a single binary. K3s is different from other packaged solutions in that there is no need to install a heavy driver to run the program. This is one of the most significant advantages of using k3s for installing Kubernetes. It is also packed in with Kubectl CLI that will be required to send Kubernetes commands. 

With little talking, let us start the installation process. But before installing Kubernetes, you must install K3s on your laptop or desktop.  

1) You will have to run the following command to install K3s on your device:          

Prompting this command automatically installs the latest and updated version of Kubernetes and automatically registers some system services for K3s.

2) Once the registration of system services is done, and the installation process is completed, we will move to the next step. The next step involves running the below-mentioned command. The following command will prompt the software to copy the Kubectl configuration file generated automatically into your ".kube" directory.  

3) Once the configuration file is copied in the ".kube" location, you must convey the following command to K3s to make this configuration file usable. The next command is as follows: 

You may add this to the /.bashrc or /.profile file so that the change is automatically applied once you re-login.

4) Now, you have to run the following command, which is the last step:

Once you run this command, you will see a single node appearing on the screen. The hostname of your machine will represent the node. If you know the node is ready, congrats; you can now use the Kubernetes cluster on your device.

 

What tasks are performed by Kubernetes?

Kubernetes is a distribution of the Linux kernel. It enables you to encapsulate the underlying hardware of nodes (servers) and provides a standard interface for programs that use the shared pool of resources.

Kubernetes allows you to manage cloud applications and microservices' resource allocation and traffic. It also aids in the simplification of numerous aspects of service-oriented infrastructures. Kubernetes lets you control when and where containerized applications execute and discover resources and tools.

Some essential tasks performed by Kubernetes are as follows:

1) Dashboard: Kubernetes helps in deploying and accessing the dashboard's user interface and facilitates monitoring and managing containerized solutions.

2) Helps in the smooth running of applications: It facilitates rolling updates, uploading information into pods, coordinating application management tasks, etc.

3) Configuration-related tasks: These help in configuring containers and pods at periodic intervals.

4) Parallel processing: It also facilitates parallel processing while running programs.

 

Bottom line:

Kubernetes is only sometimes the best solution for smaller applications. Still, it's a robust and versatile alternative for large enterprises, fast-growing startups, or businesses wishing to replace a legacy application. It is always complex to adopt new procedures and technologies. However, the more adaptable and user-friendly you can make this famously tricky technology, the better and more productive your team will be.

The ideal approach to get started is to offer dev teams access to the software as soon as possible so they can test their code and avoid costly mistakes later on.

A Kubernetes architectural diagram can also assist teams in understanding the fundamentals. This visualizes the automated strategy for adopting, upgrading, and managing containerized apps, making it easier for teams to comprehend the process.