Kubernetes is a container management tool that automates the deployment, scaling, and operations of an application. It has become the de facto container orchestrator, with more than 80% of companies using it in some capacity.
In the previous blog of 'Let's learn Kubernetes' Series, we have seen the basic definition of Kubernetes, pods, Nodes, controllers among others.

Let's Learn Kubernetes - Basics - 1

Prashant Ghildiyal ・ Sep 29 '21

#kubernetes #devops #beginners #go

In this series we will go a little deeper to understand concepts like services, Load balancers and others. In this we'll give a short explanation of each concept and then post a link that explains the same in-depth.

Before diving in, it would be great if you can check out our repo Devtron, End-to-End Kubernetes Software Delivery Workflow, which makes the DevOps workflow flawless for Developers, DevOps Engineers.

Services

Kubernetes Services enables a group of pods that provide a specific function to have a unique IP Address and a name. A Kubernetes service can be used to easily expose an application deployed on a set of pods using a single endpoint. Service is both a REST object and an abstraction that defines:

• A set of pods
• A policy to access them

The article discusses what are Kubernetes services, Attributes of the K8s services, Defining them and creating new services.

Kubernetes Services

Load Balancer, ClusterIP, NodePort

Load Balancer

Load balancing is a technique for distributing network traffic or client requests among many servers. The load balancer, when utilized correctly, may assist to optimise scalability and availability. This is a crucial technique that should be correctly implemented in a solution; otherwise, clients will be unable to contact the servers.

ClusterIP

Within your cluster, a ClusterIP offers network communication. It is generally inaccessible from the outside. You can utilise these services to connect your workloads inside.

NodePort

Every node in your cluster has an open port called a NodePort. Even if your application is operating on a separate node, Kubernetes transparently redirects incoming traffic on the NodePort to your service.

A Comprehensive video by Nana explaining what is Loadbalancer, ClusterIP & Nodeport and the difference between them.

You can also read a detailed article on ClusterIP here:

Working With ClusterIP Service Type In Kubernetes

Ingress

Kubernetes Ingress is an API object that provides routing rules to manage external users' access to the services in a Kubernetes cluster, typically via HTTPS/HTTP.

Below write-up gives a comprehensive look of what is Ingress and what is its uses.

What is Kubernetes Ingress?

Ingress Controller

An Ingress controller is a specialized load balancer for Kubernetes (and other containerized) environments. An Ingress controller abstracts away the complexity of Kubernetes application traffic routing and provides a bridge between Kubernetes services and external ones.

Ingress controller

Below link defines Ingress controller and what it can do.

DNS for K8s

In the Article below, it is explained how DNS can help make it easier to access services.

Kubernetes DNS for Services and Pods

I will be continuing this series to include more fundamental topics of Kubernetes under 'Let's learn Kubernetes' series title.