Kubernetes networking enables communication between pods, services, and external clients. It ensures connectivity, scalability, and security for applications running inside a cluster.

In this article, we will cover:

1. Pod-to-Pod communication
2. Services for exposing applications
3. Ingress Controllers for managing external access

In Kubernetes, securing your cluster and resources is paramount. Role-Based Access Control (RBAC) is a powerful tool for controlling access within Kubernetes. It allows administrators to define roles with specific permissions, ensuring that users or services can only access the resources they need.

In this article, we’ll dive into the key components of Kubernetes RBAC and explore how to implement security effectively.

Key RBAC Components

Kubernetes RBAC uses the following resources:

Kubernetes workloads are typically managed using Deployments, which handle stateless applications. However, some applications require stable network identities or storage persistence, while others must run on every node in the cluster.

• StatefulSets are used for stateful applications like databases.
• DaemonSets are used for node-specific workloads like logging and monitoring agents.

In this article, we’ll explore both in detail.

1. Kubernetes StatefulSets

A StatefulSet is a Kubernetes resource designed for stateful applications where each pod:

Containers are ephemeral by nature, meaning data stored inside them disappears when a pod is restarted. To persist data in Kubernetes, we use Volumes and Persistent Volumes.

1. Kubernetes Volumes: Basics

A Volume in Kubernetes provides storage that can be shared across containers within a pod. Unlike a container’s filesystem, a Kubernetes volume exists as long as the pod exists.

Types of Kubernetes Volumes:

Volume Type Description emptyDir Temporary storage that exists while the pod is running. hostPath Mounts a directory from the worker node’s filesystem. configMap / secret Mounts a ConfigMap or Secret as a file. persistentVolumeClaim Connects to a Persistent Volume (PV) for long-term storage.

Applications running in Kubernetes often require configuration settings such as database URLs, API keys, and environment variables. Kubernetes provides two key resources for managing this configuration data:

1. ConfigMaps – Store non-sensitive configuration data like environment variables and configuration files.
2. Secrets – Store sensitive information like passwords, tokens, and certificates securely.

What is a ConfigMap?

A ConfigMap allows you to store configuration data separately from your application code. This enables dynamic configuration updates without modifying container images.

Kubernetes is a powerful container orchestration system that automates the deployment, scaling, and management of containerized applications. To fully understand how Kubernetes operates, we must first explore its architecture and components.

High-Level Overview

A Kubernetes cluster consists of two main components:

• Control Plane (Master Node): Manages the cluster and ensures the desired state of applications.
• Worker Nodes: Execute containerized applications and respond to instructions from the control plane.

Kubernetes manages containerized applications using fundamental building blocks like Pods, Deployments, and ReplicaSets. These concepts enable scalable, resilient, and automated deployments.

What is a Pod?

A Pod is the smallest deployable unit in Kubernetes. It represents one or more containers that share the same network namespace and storage.

Key Features of a Pod:

• Can contain one or multiple containers.
• Shares network and storage among containers in the pod.
• Has a unique IP address inside the cluster.

Example: A Simple Pod Manifest

In Kubernetes, Pods are ephemeral, meaning they can be created and destroyed dynamically. To allow stable communication between different components of an application, Kubernetes provides Services.

A Service exposes a set of Pods using a stable IP and DNS name, ensuring reliable networking within and outside the cluster.

Why Do We Need Kubernetes Services?

• Pods have dynamic IP addresses that change when restarted.
• Services provide a fixed virtual IP (VIP) that remains stable.
• Services enable load balancing across multiple pod instances.

Types of Kubernetes Services

Kubernetes provides four main types of services:

Helm is a powerful package manager for Kubernetes that simplifies the deployment, management, and scaling of applications. Instead of manually defining complex Kubernetes YAML files, you can use Helm charts, which provide a structured and reusable way to deploy applications.

In this guide, we will explore:

• What Helm charts are
• Their key components
• How to create and deploy a Helm chart
• A practical example

Microsoft Forms is a simple way to collect user input, and Power Automate can process that data by triggering API calls. This guide will walk you through the process of capturing responses from a Microsoft Form and sending them to an external API.

Prerequisites

Before starting, ensure you have: • A Microsoft 365 account • Access to Microsoft Forms • A Power Automate (Flow) license • An API endpoint to call