Kubernetes Core Components

Kubernetes is a powerful container orchestration system that manages containerized applications across a cluster of machines. It has a master-worker architecture, where the Control Plane (Master) manages the cluster, and Worker Nodes run the applications.

🧠 Master Components (Control Plane)

The Control Plane is responsible for managing the cluster and orchestrating workloads.

📜 1. API Server (kube-apiserver)

• Acts as the front-end for the Kubernetes control plane.
• Receives REST commands and updates cluster state.

🧠 2. Scheduler (kube-scheduler)

• Assigns workloads (pods) to worker nodes based on resources and constraints.

👮 3. Controller Manager (kube-controller-manager)

• Runs controllers that watch the state of the cluster and make changes to reach the desired state.

📘 4. etcd

• A key-value store used as the backing store for all cluster data.

🔒 5. Cloud Controller Manager (optional)

• Integrates with cloud provider APIs (e.g., AWS, GCP) for things like Load Balancers and Node management.

Master Components Flowchart

🔧 Worker Node Components

Worker nodes are where the actual workloads (pods/containers) run.

🧱 1. Kubelet

• Ensures containers are running in a pod.
• Communicates with the API server and reports back status.

📦 2. Kube Proxy

• Maintains network rules for pod communication and service access.

🐳 3. Container Runtime

• Responsible for running containers (e.g., containerd, Docker, CRI-O).

Worker Components Flowchart

🕸️ Master-Worker Interaction Overview

This diagram shows how master and worker components interact in a full cluster:

✅ Summary Table