Kubernetes

Introduction Kubernetes is powerful, but what’s the brain behind all those kubectl commands? That role is played by the kube-apiserver — the front door to your Kubernetes cluster. Everything goes through it: creating pods, scaling deployments, checking health — you name it. Let’s break it down in a way that’s easy to understand. What is kube-apiserver? kube-apiserver is the central communication hub of Kubernetes. It exposes the Kubernetes API and handles: ...

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. ...

Caching in Kubernetes Ingress Caching is a key strategy to reduce backend load and improve response times for clients. In Kubernetes, caching is usually implemented through the Ingress controller — particularly with NGINX. Why Use Caching? Reduce load on backend services Improve speed for repeated requests Minimize cost and bandwidth Smooth handling of traffic spikes Common Caching Setup: NGINX Ingress The NGINX Ingress Controller supports proxy caching via annotations. Step 1: Enable caching in your Ingress resource apiVersion: networking.k8s.io/v1 kind: Ingress metadata: name: my-app-ingress annotations: nginx.ingress.kubernetes.io/proxy-cache: "my-cache-zone" nginx.ingress.kubernetes.io/proxy-cache-key: "$scheme$request_method$host$request_uri" nginx.ingress.kubernetes.io/proxy-cache-use-stale: "error timeout updating http_500 http_502 http_503 http_504" spec: rules: - host: myapp.example.com http: paths: - path: / pathType: Prefix backend: service: name: my-app port: number: 80 Step 2: Define the cache zone in the NGINX ConfigMap apiVersion: v1 kind: ConfigMap metadata: name: nginx-configuration namespace: ingress-nginx data: proxy-cache-paths: | my-cache-zone keys_zone=my-cache-zone:10m max_size=100m inactive=60m use_temp_path=off; ⚠️ Requires restarting the Ingress controller or reloading its config. ...