Introduction to Azure Kubernetes Service (AKS)

Azure Kubernetes Service (AKS) is a managed Kubernetes offering that simplifies deploying, managing, and scaling containerised applications. Azure manages the Kubernetes control plane — the API server, etcd, scheduler, and controller manager — while you manage the worker nodes that run your application workloads. This lesson covers the architecture, key concepts, and your first AKS deployment.

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What Is Kubernetes?

Kubernetes (K8s) is an open-source container orchestration platform originally developed by Google. It automates:

• Scheduling — deciding which node a container runs on
• Scaling — adding or removing container replicas based on demand
• Self-healing — restarting failed containers and replacing unhealthy nodes
• Service discovery — providing DNS names and load balancing for services
• Rolling updates — deploying new versions with zero downtime
• Configuration management — injecting secrets and config maps into containers

Kubernetes is powerful but complex to operate. AKS removes much of the operational burden by managing the control plane for you.

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AKS Architecture

+--------------------------------------------------+
|                Azure Managed                      |
|  +--------------------------------------------+  |
|  |           Control Plane (Free)              |  |
|  |  API Server | etcd | Scheduler | Controllers|  |
|  +--------------------------------------------+  |
+--------------------------------------------------+
         |                    |
         v                    v
+------------------+  +------------------+
|   Node Pool 1    |  |   Node Pool 2    |
|   (System)       |  |   (User / App)   |
|  +------+ +----+ |  |  +------+ +----+ |
|  | Node | |Node| |  |  | Node | |Node| |
|  | VM   | | VM | |  |  | VM   | | VM | |
|  +------+ +----+ |  |  +------+ +----+ |
+------------------+  +------------------+

Control Plane

• Managed by Azure — you do not pay for control plane VMs
• Runs the Kubernetes API server, etcd (cluster state store), scheduler, and controllers
• Automatically patched and upgraded by Azure
• SLA options: free tier (no SLA), Standard (99.95% for AZ clusters), Premium (99.99% mission-critical)

Node Pools

• System node pool — runs Kubernetes system pods (CoreDNS, metrics-server, kube-proxy). At least one system pool is required.
• User node pools — run your application workloads. You can have multiple pools with different VM sizes, OS types, and scaling configurations.
• Nodes are Azure Virtual Machines (or Virtual Machine Scale Sets) that you pay for.

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Creating Your First AKS Cluster

Using the Azure CLI

# Create a resource group
az group create --name rg-aks --location uksouth

# Create an AKS cluster
az aks create \
  --resource-group rg-aks \
  --name my-aks-cluster \
  --node-count 3 \
  --node-vm-size Standard_D4s_v5 \
  --generate-ssh-keys \
  --attach-acr mycompanyacr \
  --network-plugin azure \
  --enable-managed-identity

Connecting to the Cluster

# Get credentials and configure kubectl
az aks get-credentials \
  --resource-group rg-aks \
  --name my-aks-cluster

# Verify the connection
kubectl get nodes

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Core Kubernetes Objects

Pods

A pod is the smallest deployable unit in Kubernetes — one or more containers that share networking and storage.

apiVersion: v1
kind: Pod
metadata:
  name: my-app
spec:
  containers:
    - name: web
      image: mycompanyacr.azurecr.io/myapp:1.0
      ports:
        - containerPort: 8080

Deployments