Kubernetes Tutorial for Beginners: Basics, Features, Architecture

Before we start this Kubernetes tutorial, let’s learn:

Why you need containers?

Today’s internet user never accept downtime. Therefore developers have to find a method to perform maintenance and update without interrupting their services.

Therefore container, which is isolated environments. It includes everything needed for application to run. It makes it easy for a developer to edit and deploying apps. Moreover, containerization has become a preferred method for packaging, deploying, and update web apps.

In this Kubernetes tutorial for beginners, you will learn Kubernetes basics like:

• What is Kubernetes?
• Why you need containers?
• What task are performed by Kubernetes?
• Why use Kubernetes?
• Features of Kubernetes
• Kubernetes Basics
• Kubernetes Architecture
• Other Key Terminologies
• Kubernetes vs. Docker Swarm
• Advantages of Kubernetes
• Disadvantages of Kubernetes

What task are performed by Kubernetes?

Kubernetes is the Linux kernel which is used for distributed systems. It helps you to be abstract the underlying hardware of the nodes(servers) and offers a consistent interface for applications that consume the shared pool of resources.

Features of Kubernetes

Here are the essential Kubernetes features:

• Automated Scheduling
• Self-Healing Capabilities
• Automated rollouts & rollback
• Horizontal Scaling & Load Balancing
• Offers environment consistency for development, testing, and production
• Infrastructure is loosely coupled to each component can act as a separate unit
• Provides a higher density of resource utilization
• Offers enterprise-ready features
• Application-centric management
• Auto-scalable infrastructure
• You can create predictable infrastructure

Kubernetes Basics

Now in this Kubernetes tutorial, we will learn some important Basics of Kubernetes:

• Cluster:

  It is a collection of hosts(servers) that helps you to aggregate their available resources. That includes ram, CPU, ram, disk, and their devices into a usable pool.

• Master:

  The master is a collection of components which make up the control panel of Kubernetes. These components are used for all cluster decisions. It includes both scheduling and responding to cluster events.

• Node:

  It is a single host which is capable of running on a physical or virtual machine. A node should run both kube-proxy, minikube, and kubelet which are considered as a part of the cluster.

• Namespace:

  It is a logical cluster or environment. It is a widely used method which is used for scoping access or dividing a cluster.

Other Key Terminologies

Replication Controllers

A replication controller is an object which defines a pod template. It also controls parameters to scale identical replicas of Pod horizontally by increasing or decreasing the number of running copies.

Replication Sets

Replication sets are an interaction on the replication controller design with flexibility in how the controller recognizes the pods it is meant to manage. It replaces replication controllers because of their higher replicate selection capability.

Deployments

Deployment is a common workload which can be directly created and manage. Deployment use replication set as a building block which adds the feature of life cycle management.

Stateful Sets

It is a specialized pod control which offers ordering and uniqueness. It is mainly used to have fine-grained control, which you have a particular need regarding deployment order, stable networking, and persistent data.

Daemon Sets

Daemon sets are another specialized form of pod controller that runs a copy of a pod on every node in the cluster. This type of pod controller is an effective method for deploying pods that allows you to perform maintenance and offers services for the nodes themselves.

Kubernetes vs. Docker Swarm

Here are important differences between Kubernetes vs Docker.

Parameter	Docker Swarm	Kubernetes
Scaling	No Autoscaling	Auto-scaling
Load balancing	Does auto load balancing	Manually configure your load balancing settings
Storage volume sharing	Shares storage volumes with any other container	Shares storage volumes between multiple containers inside the same Pod
Use of logining and monitoring tool	Use 3rd party tool like ELK	Provide an in-built tool for logging and monitoring.
Installation	Easy & fast	Complicated & time-consuming
GUI	GUI not available	GUI is available
Scalability	Scaling up is faster than K8S, but cluster strength not as robust	Scaling up is slow compared to Swarm, but guarantees stronger cluster state Load balancing requires manual service configuration
Load Balancing	Provides a built-in load balancing technique	Process scheduling to maintain services while updating
Updates & Rollbacks Data Volumes Logging & Monitoring	Progressive updates and service health monitoring.	Only shared with containers in same Pod Inbuilt logging & monitoring tools.

Advantages of Kubernetes

• Easy organization of service with pods
• It is developed by Google, who bring years of valuable industry experience to the table
• Largest community among container orchestration tools
• Offers a variety of storage options, including on-premises, SANs and public clouds
• Adheres to the principals of immutable infrastructure
• Kubernetes can run on-premises bare metal, OpenStack, public clouds Google, Azure, AWS, etc.
• Helps you to avoid vendor lock issues as it can use any vendor-specific APIs or services except where Kubernetes provides an abstraction, e.g., load balancer and storage.
• Containerization using kubernetes allows package software to serve these goals. It will enable applications that need to be released and updated without any downtime.
• Kubernetes allows you to assure those containerized applications run where and when you want and helps you to find resources and tools which you want to work.

Disadvantages of Kubernetes

• Kubenetes dashboard not as useful as it should be
• Kubernetes is a little bit complicated and unnecessary in environments where all development is done locally.
• Security is not very effective.

Summary:

• Container helps an organization to perform maintenance and update without interrupting services
• Kubernetes is an example of a container management system developed in the Google platform.
• The biggest advantage of using Kubernetes is that it can run on-premises OpenStack, public clouds Google, Azure, AWS, etc.
• Kubernetes offers automated Scheduling and Self-Healing Capabilities.
• Cluster, master, node, and namespace are important basic of kubernetes
• Master node and work node are important components of Kubernetes architecture.
• Replication Controllers, Replication sets, Deployments, Stateful Sets, Daemon Sets are other important terms used in Kubernetes.
• Docker swarm does not allow auto-scaling while Kubernetes allows auto-scaling.
• The biggest drawback of Kubenetes is that it’s dashboard not very useful and effective