DevOps

What is Docker? Docker is a tool that makes it easier to create, deploy, and run applications using containers. Why use Docker? Imagine you built an app that works perfectly on your machine. You send it to your teammate, and suddenly… it doesn’t work! Different OS, different dependencies, different versions — it’s a mess. Docker solves this by putting your app and everything it needs into a container. A container is like a box with your app, its settings, and all dependencies — isolated and portable. ...

Introduction Ever wondered who actually starts, stops, and monitors containers on your Kubernetes node? That’s the job of kubelet — the silent agent that lives on every node and makes sure containers are running as expected. Let’s explore kubelet in a clear and friendly way. What is kubelet? kubelet is an agent that runs on each Kubernetes node. It talks to the control plane and makes sure the containers assigned to that node are healthy and running. ...

Introduction One of the magical things about Kubernetes is that it just knows how to restart pods, create replicas, or handle node failures. But how? Behind the scenes, there’s a key component called kube-controller-manager. Let’s demystify what it does — and why it’s essential. What is kube-controller-manager? It’s a Kubernetes control plane component that runs multiple controllers — small control loops that handle routine tasks. Think of it like an army of little workers keeping your cluster healthy and aligned with your YAML definitions. ...

Introduction If you’re just getting started with Kubernetes, its architecture can feel a bit overwhelming. Let’s break it down into understandable pieces. Kubernetes is like a well-organized team — and each component has a specific role. Control Plane vs Node Components Kubernetes is divided into two major layers: Control Plane – the brain of the cluster, makes decisions. Node Components – the workers, run the actual workloads. 🧠 Control Plane Components 1. API Server (kube-apiserver) The API server is the front door to your cluster. Everything — kubectl, dashboards, even internal components — talks to the cluster via this API. ...

Introduction Have you ever wondered how Kubernetes decides where to run your pods? That’s where the kube-scheduler comes into play. It’s one of the most important — yet often overlooked — components in the Kubernetes control plane. Let’s explore how it works in plain English. What is kube-scheduler? kube-scheduler is the default scheduler for Kubernetes. Its job is simple but critical: 🧠 It picks a node for every pod that doesn’t yet have a node assigned. ...