With a solid understanding of Kubernetes architecture, you're ready to set up a cluster. This section covers various options for creating a Kubernetes cluster, from local development environments to production-ready setups.

Kubernetes Cluster Options

There are several ways to run Kubernetes, depending on your needs:

Local development clusters: Lightweight options for your machine
Self-managed clusters: Full control over your infrastructure
Managed Kubernetes services: Cloud provider-managed control plane
Kubernetes distributions: Vendor-supported packages with additional features

Let's explore each option, starting with the simplest.

Local Development Clusters

For learning and development, you can run Kubernetes on your local machine.

Minikube

Minikube is a lightweight Kubernetes implementation that creates a VM on your local machine and deploys a simple cluster with a single node.

Prerequisites

2 CPUs or more
2GB of free memory
20GB of free disk space
Container or virtual machine manager (Docker, Hyperkit, VirtualBox, etc.)

Installation

For macOS with Homebrew:

brew install minikube

For Windows with Chocolatey:

choco install minikube

For Linux:

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install minikube-linux-amd64 /usr/local/bin/minikube

Starting a Cluster

Start a basic Minikube cluster:

minikube start

Or customize with more resources:

minikube start --cpus 4 --memory 8192 --disk-size 50g

Minikube provides a dashboard for visualization:

minikube dashboard

Kind (Kubernetes IN Docker)

Kind runs Kubernetes clusters inside Docker containers, making it quick and easy to set up test clusters.

Installation

For macOS with Homebrew:

brew install kind

For Windows with Chocolatey:

choco install kind

For Linux:

curl -Lo ./kind https://kind.sigs.k8s.io/dl/latest/kind-linux-amd64
chmod +x ./kind
sudo mv ./kind /usr/local/bin/kind

Creating a Cluster

Create a basic Kind cluster:

kind create cluster --name my-cluster

For multi-node clusters, create a configuration file kind-config.yaml:

kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
  - role: control-plane
  - role: worker
  - role: worker

Then create the cluster with:

kind create cluster --config kind-config.yaml

Docker Desktop

Docker Desktop for Mac and Windows includes a Kubernetes option that's easily enabled from the settings.

Open Docker Desktop preferences
Go to the Kubernetes tab
Check "Enable Kubernetes"
Click "Apply & Restart"

This is one of the simplest ways to start if you already use Docker Desktop.

Self-Managed Production Clusters

For production workloads, you can set up and manage your own Kubernetes clusters.

kubeadm

kubeadm is the official Kubernetes cluster bootstrapping tool. It handles the setup of the control plane and worker nodes.

Prerequisites

Multiple Linux machines (virtual or physical)
2 GB or more of RAM per machine
2 CPUs or more per machine
Full network connectivity between all machines in the cluster
sudo privileges on all machines
Container runtime installed (Docker, containerd, CRI-O)

Installation Steps

First, install kubeadm on all nodes:

# Update package list
sudo apt-get update

# Install prerequisites
sudo apt-get install -y apt-transport-https ca-certificates curl

# Add Kubernetes repository key
curl -fsSL https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-archive-keyring.gpg

# Add Kubernetes repository
echo "deb [signed-by=/etc/apt/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list

# Update package list again
sudo apt-get update

# Install kubelet, kubeadm, and kubectl
sudo apt-get install -y kubelet kubeadm kubectl

# Pin their version to prevent auto-updates
sudo apt-mark hold kubelet kubeadm kubectl

On the control plane node, initialize the cluster:

sudo kubeadm init --pod-network-cidr=192.168.0.0/16

Set up kubectl access:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Install a pod network add-on (example with Calico):

kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

Join worker nodes to the cluster using the token from the kubeadm init output:

sudo kubeadm join <control-plane-IP>:6443 --token <token> --discovery-token-ca-cert-hash <hash>

kubespray

Kubespray uses Ansible to automate Kubernetes cluster deployment and configuration in a more sophisticated manner than kubeadm.

# Clone the Kubespray repository
git clone https://github.com/kubernetes-sigs/kubespray.git
cd kubespray

# Install dependencies
pip install -r requirements.txt

# Copy the sample inventory and customize it
cp -rfp inventory/sample inventory/mycluster

# Update the inventory file with your servers
vi inventory/mycluster/inventory.ini

# Deploy Kubernetes with Ansible
ansible-playbook -i inventory/mycluster/inventory.ini cluster.yml -b

Managed Kubernetes Services

Managed services offload the control plane management to cloud providers, allowing you to focus on your applications.

DigitalOcean Kubernetes (DOKS)

DigitalOcean offers a managed Kubernetes service that simplifies setup and maintenance. Sign up with DigitalOcean to get $200 in free credits to try DOKS.

You can create a cluster through the web UI or using their CLI tool, doctl:

# Install doctl
brew install doctl  # For macOS

# Authenticate with DigitalOcean
doctl auth init

# Create a Kubernetes cluster
doctl kubernetes cluster create my-cluster \
  --region nyc1 \
  --size s-2vcpu-4gb \
  --count 3

Amazon EKS (Elastic Kubernetes Service)

Amazon EKS is AWS's managed Kubernetes service. You can create clusters through the AWS Management Console, AWS CLI, or eksctl:

eksctl create cluster \
  --name my-cluster \
  --region us-west-2 \
  --nodegroup-name standard-workers \
  --node-type t3.medium \
  --nodes 3 \
  --nodes-min 1 \
  --nodes-max 4

Google Kubernetes Engine (GKE)

GKE is Google Cloud's managed Kubernetes service, often considered one of the most mature offerings:

gcloud container clusters create my-cluster \
  --zone us-central1-a \
  --num-nodes 3 \
  --machine-type e2-standard-2

Azure Kubernetes Service (AKS)

Microsoft's managed Kubernetes offering:

az aks create \
  --resource-group myResourceGroup \
  --name myAKSCluster \
  --node-count 3 \
  --enable-addons monitoring \
  --generate-ssh-keys

Kubernetes Distributions

Several vendors package Kubernetes with additional tools and support:

Red Hat OpenShift: Enterprise Kubernetes platform with developer and operations-focused tools
Rancher: Complete container management platform
VMware Tanzu Kubernetes Grid: Enterprise-ready Kubernetes runtime
k3s: Lightweight Kubernetes distribution for edge and IoT

Accessing Your Cluster

No matter which option you choose, you'll interact with your cluster using kubectl, the Kubernetes command-line tool.

Installing kubectl

For macOS:

brew install kubectl

For Windows with Chocolatey:

choco install kubernetes-cli

For Linux:

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
chmod +x kubectl
sudo mv kubectl /usr/local/bin/

Configuring kubectl

kubectl uses a configuration file (kubeconfig) located at ~/.kube/config by default.

For local clusters, the setup command usually configures kubectl automatically. For remote clusters, you'll need to download the kubeconfig:

# Example with DigitalOcean
doctl kubernetes cluster kubeconfig save my-cluster

# Example with AWS EKS
aws eks update-kubeconfig --name my-cluster --region us-west-2

# Example with GKE
gcloud container clusters get-credentials my-cluster --zone us-central1-a

Verifying Cluster Access

Ensure kubectl can communicate with your cluster:

kubectl cluster-info

You should see the Kubernetes control plane address and CoreDNS information.

Check the nodes in your cluster:

kubectl get nodes

This should show all the nodes in your cluster with their status, roles, and versions.

Cluster Configuration

Setting Up a High-Availability Cluster

For production, a high-availability setup is crucial. This typically involves:

Multiple control plane nodes
Multiple worker nodes
External etcd cluster
Load balancer for the API server

If you're using kubeadm, initialize with:

kubeadm init --control-plane-endpoint "LOAD_BALANCER_DNS:LOAD_BALANCER_PORT" \
    --upload-certs \
    --pod-network-cidr=192.168.0.0/16

Then join additional control plane nodes with:

kubeadm join LOAD_BALANCER_DNS:LOAD_BALANCER_PORT \
    --token <token> \
    --discovery-token-ca-cert-hash <hash> \
    --control-plane \
    --certificate-key <certificate-key>

Node Labels and Taints

Customize how pods are scheduled to nodes with labels and taints.

Add a label to a node:

kubectl label nodes worker-1 disktype=ssd

Add a taint to keep certain workloads away:

kubectl taint nodes worker-2 dedicated=gpu:NoSchedule

Role-Based Access Control (RBAC)

Configure RBAC to control access to your cluster resources:

Create a role:

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: default
  name: pod-reader
rules:
  - apiGroups: ['']
    resources: ['pods']
    verbs: ['get', 'watch', 'list']

Create a role binding:

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: read-pods
  namespace: default
subjects:
  - kind: User
    name: jane
    apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: pod-reader
  apiGroup: rbac.authorization.k8s.io

Networking Add-ons

Kubernetes needs a Container Network Interface (CNI) plugin to handle pod networking:

Calico: Provides networking and network policy
Flannel: Simple overlay network
Cilium: Advanced networking with eBPF
Weave Net: Multi-host Docker networking

Install Calico with:

kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

Upgrading Clusters

Kubernetes releases new versions regularly. Upgrading involves these steps:

Upgrade the control plane
Upgrade worker nodes
Upgrade cluster add-ons

For kubeadm clusters:

# Control plane
sudo apt-get update
sudo apt-get install -y kubeadm=1.24.0-00
sudo kubeadm upgrade plan
sudo kubeadm upgrade apply v1.24.0

# Worker nodes
kubectl drain worker-1 --ignore-daemonsets
sudo apt-get update
sudo apt-get install -y kubelet=1.24.0-00 kubectl=1.24.0-00
sudo systemctl restart kubelet
kubectl uncordon worker-1

For managed services, upgrades are often just a few clicks in the UI or a simple CLI command.

Backup and Disaster Recovery

Regularly back up your cluster's critical components:

etcd data
Persistent volumes
Configuration

Back up etcd:

ETCDCTL_API=3 etcdctl \
  --endpoints=https://127.0.0.1:2379 \
  --cacert=/etc/kubernetes/pki/etcd/ca.crt \
  --cert=/etc/kubernetes/pki/etcd/server.crt \
  --key=/etc/kubernetes/pki/etcd/server.key \
  snapshot save snapshot.db

Choosing the Right Option

When selecting a Kubernetes solution, consider these factors:

Expertise required: Managed services require less Kubernetes expertise
Cost: Self-managed can be cheaper but requires more operational effort
Control: Self-managed provides more control over configuration
Scalability: All solutions can scale, but with different levels of effort
Integration: Consider how well it integrates with your existing tools

For many teams, starting with a managed service like DigitalOcean Kubernetes (Get $200 in free credits) provides a good balance of simplicity and capability while learning.

In the next section, we'll explore how to work with pods and containers, the fundamental units of deployment in Kubernetes.

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