Kubernetes Architecture: On-Prem, Minikube, and Public Cloud Deployments

Kubernetes (K8s) is a powerful orchestration platform designed to manage containerized applications at scale. While its core architecture remains consistent, its deployment varies significantly based on whether it's running on-premises , in Minikube (local setup) , or on a public cloud provider. This blog explores Kubernetes architecture across these environments, detailing their design, components, and deployment strategies.

Core Kubernetes Architecture 🏗️

Kubernetes Architecture

Regardless of the deployment environment, Kubernetes follows a master-worker node architecture , which consists of:

1. Control Plane (Master Node)

The control plane manages the cluster and ensures the desired state of the system. It includes:

• API Server (kube-apiserver) 📡 – The gateway for all cluster operations.

• Controller Manager (kube-controller-manager) 🔄 – Handles node lifecycles, replication, and endpoints.

• Scheduler (kube-scheduler) 📊 – Assigns workloads (pods) to available nodes based on resources.

• etcd 🗂️ – A distributed key-value store that maintains cluster state and configuration.

2. Worker Nodes

Each worker node runs workloads (pods) and includes:

• Kubelet 🔄 – The node agent that communicates with the API server and manages container execution.

• Container Runtime 🛠️ – Software like Docker , containerd , or CRI-O to run containers.

• Kube Proxy 🔌 – Handles network communication and load balancing within the cluster.

• Pods 🏠 – The smallest unit of deployment in Kubernetes.

Kubernetes Deployment Architectures

The way Kubernetes is deployed varies based on the infrastructure, whether it is on-premises , Minikube , or a public cloud provider.

1. On-Premises Kubernetes Deployment 🏢

On Prem Kubernetes Architecture

Deploying Kubernetes on-prem gives full control over hardware, networking, and security. Organizations often use bare-metal servers or virtual machines to run Kubernetes.

Key Characteristics:

✅ Requires manual installation (e.g., using kubeadm , k3s , or RKE).

✅ Needs a separate etcd cluster for high availability.

✅ Uses software-defined networking (Calico, Flannel, Cilium).

✅ Requires external load balancers (e.g., MetalLB) for service exposure.

Example On-Prem Deployment using kubeadm

 # Initialize Kubernetes master node
kubeadm init --pod-network-cidr=192.168.1.0/16

# Join worker nodes
kubeadm join <master-node-ip>:6443 --token <token> --discovery-token-ca-cert-hash sha256:<hash>

Pros & Cons

✅ Full control over infrastructure & security.

✅ No dependency on cloud providers.

❌ Higher maintenance effort (manual upgrades, networking, storage setup).

❌ Requires on-prem load balancer & monitoring setup.

2. Minikube Deployment (Local Kubernetes) 🖥️

Minikube is a lightweight Kubernetes implementation that runs on a single local machine , perfect for testing and development.

Key Characteristics:

✅ Runs a single-node Kubernetes cluster on a local machine.

✅ Uses virtual machines (VMs) , Docker , or bare-metal for execution.

✅ Supports different drivers (Docker, VirtualBox, Hyper-V).

✅ Includes built-in LoadBalancer & Ingress Controller for local testing.

Example Minikube Deployment

 # Start a Minikube cluster
minikube start --driver=docker

# Deploy a sample application
kubectl create deployment hello-minikube --image=k8s.gcr.io/echoserver:1.4

Pros & Cons

✅ Fast, lightweight, and ideal for local development.

✅ Requires minimal system resources.

❌ Not suitable for production (single-node setup).

❌ No built-in high availability.

3. Public Cloud Kubernetes (EKS, GKE, AKS, DOKS, etc.) ☁️

Kubernetes Architecture Public Cloud

Public cloud providers offer managed Kubernetes services such as:

• Amazon Elastic Kubernetes Service (EKS) 🌍

• Google Kubernetes Engine (GKE) 🔵

• Azure Kubernetes Service (AKS) 🟦

• DigitalOcean Kubernetes (DOKS) 🏝️

Key Characteristics:

✅ Fully managed control plane (No need to manage API server, etcd, etc.).

✅ Seamless cloud integrations (Auto-scaling, IAM roles, storage, monitoring).

✅ Multi-zone & high availability options.

✅ Built-in LoadBalancer & Ingress with cloud-native solutions.

Example AWS EKS Deployment

 # Create an EKS cluster using eksctl
eksctl create cluster --name my-cluster --region us-west-1 --node-type t3.medium --nodes 3

Pros & Cons

✅ Easier to deploy & scale (cloud providers handle infra setup).

✅ Highly available & auto-scalable.

✅ Integrated monitoring & security features.

❌ Vendor lock-in with cloud provider.

❌ Higher operational costs compared to on-prem solutions.

Comparison Table: On-Prem vs. Minikube vs. Public Cloud

Feature	On-Prem Kubernetes	Minikube	Public Cloud Kubernetes
Control Plane	Self-managed	Single-node	Cloud-managed
High Availability	✅ Yes	❌ No	✅ Yes
Scalability	✅ Manual	❌ No	✅ Auto-scale
Networking	Custom (Calico, Flannel)	Built-in	Cloud-integrated
Load Balancing	Manual (MetalLB)	Built-in	Managed LB
Ideal Use Case	Production, enterprise infra	Local development	Scalable, production-ready

Final Thoughts

Each Kubernetes deployment model has its strengths:

• On-Prem Kubernetes provides full control and security.

• Minikube is great for testing and development.

• Public Cloud Kubernetes is ideal for scalable, managed workloads.

Understanding the differences helps in choosing the right Kubernetes environment for your workloads! 🚀