Kubernetes

About K8s

Kubernetes (often abbreviated as K8s) is an open-source container orchestration platform designed to automate the deployment, scaling, management, and operation of containerized applications across clusters of servers. It abstracts away the underlying infrastructure and provides a unified API to manage containers efficiently in production environments.

At its core, Kubernetes implements a declarative model of infrastructure management you define the desired state of your applications and the cluster continuously works to maintain that state. Whether it’s ensuring the correct number of Pods are running, replacing unhealthy containers, or distributing workloads evenly across nodes, Kubernetes handles these operational challenges automatically through its control plane components.

Kubernetes is built around the principle of desired state reconciliation. Users describe what they want (e.g., three replicas of an application running behind a load balancer), and Kubernetes controllers constantly compare this desired state against the actual cluster state, taking corrective actions whenever they drift apart.

It brings together several key capabilities critical to modern DevOps and cloud-native environments:

• Automated scaling of applications based on CPU, memory, or custom metrics.

• Self-healing mechanisms that restart or reschedule failed workloads.

• Declarative configuration management, enabling version-controlled infrastructure (GitOps).

• Service discovery and load balancing across distributed microservices.

• Rolling updates and rollbacks for zero-downtime deployments.

• Fine-grained security controls through RBAC, namespaces, and policies.

Kubernetes has become the de facto standard for running containerized workloads, empowering developers, DevOps, and security engineers to build scalable, resilient, and secure systems. Its modular and extensible design allows integration with third-party tools, admission controllers, and custom resources transforming it from a simple orchestrator into a full-fledged cloud-native operating system.

In this section, I will cover all Kubernetes concepts from the most fundamental objects like Pods, Deployments, and Services, to advanced topics such as RBAC, Networking, Security Contexts, Admission Controllers, and Cluster Security. Each concept will be explained in a detailed and technical manner, focusing not only on what it does but also how it works internally, how it behaves at runtime, and how it impacts the overall security and reliability of the cluster.