In this tutorial, we’ll deploy PostgreSQL on AKS using:

• StatefulSet


• Azure Managed Disk (CSI)


• ReadWriteOnce (RWO)


• Premium SSD storage


• Persistent volume validation

On Azure Kubernetes Service

🧠 Why Run PostgreSQL on AKS?

Common use cases:

• SaaS apps with per-tenant DB


• Internal microservice database


• Dev/Test ephemeral environments


• Platform engineering demos

Key benefits:

✅ Data survives pod restarts

✅ Azure-managed disk durability

✅ Zone-aware scheduling

✅ Snapshot + backup integration

🏗 Architecture Overview

PostgreSQL runs as:

• StatefulSet


• Backed by Azure Managed Disk
  


• Using CSI driver
  


• Access mode: ReadWriteOnce
  


• Storage SKU: Premium_LRS
  

Kubernetes dynamically provisions the disk.

Step 1️⃣ — Verify StorageClass

AKS automatically creates a default CSI storage class.

Check it:

kubectl get storageclass

Then inspect:

kubectl describe storageclass default

Look for:

Provisioner: disk.csi.azure.com

skuName: Premium_LRS

If you see Premium_LRS, you're using Premium SSD.

Step 2️⃣ — Create Namespace

kubectl create namespace postgres-demo

Step 3️⃣ — Create Secret

apiVersion: v1

kind: Secret

metadata:

  name: postgres-secret

  namespace: postgres-demo

type: Opaque

stringData:

  POSTGRES_PASSWORD: supersecurepassword

Apply:

kubectl apply -f secret.yaml

Step 4️⃣ — Create Headless Service

StatefulSets require a headless service.

apiVersion: v1

kind: Service

metadata:

  name: postgres

  namespace: postgres-demo

spec:

  clusterIP: None

  selector:

    app: postgres

  ports:

    - port: 5432

Apply:

kubectl apply -f service.yaml

Step 5️⃣ — Deploy PostgreSQL StatefulSet

⚠ Important: Azure disks contain a lost+found directory at root.

PostgreSQL refuses to initialize if the directory is not empty.

We fix this by using a subdirectory via PGDATA.

apiVersion: apps/v1

kind: StatefulSet

metadata:

  name: postgres

  namespace: postgres-demo

spec:

  serviceName: postgres

  replicas: 1

  selector:

    matchLabels:

      app: postgres

  template:

    metadata:

      labels:

        app: postgres

    spec:

      containers:

      - name: postgres

        image: postgres:15

        ports:

        - containerPort: 5432

        env:

        - name: POSTGRES_PASSWORD

          valueFrom:

            secretKeyRef:

              name: postgres-secret

              key: POSTGRES_PASSWORD

        - name: PGDATA

          value: /var/lib/postgresql/data/pgdata

        volumeMounts:

        - name: postgres-data

          mountPath: /var/lib/postgresql/data

  volumeClaimTemplates:

  - metadata:

      name: postgres-data

    spec:

      accessModes: ["ReadWriteOnce"]

      storageClassName: default

      resources:

        requests:

          storage: 10Gi

Apply:

kubectl apply -f statefulset.yaml

Step 6️⃣ — Verify Deployment

Wait for pod:

kubectl rollout status statefulset/postgres -n postgres-demo

Check PVC:

kubectl get pvc -n postgres-demo

Check pod:

kubectl get pods -n postgres-demo

You should see:

postgres-0   Running

Step 7️⃣ — Confirm Azure Disk Creation

In Azure Portal:

1. Open resource group starting with:
   

   MC_<your-rg>_<cluster>_<region>

1. Find the Managed Disk


2. Verify:

• SKU = Premium SSD


• Size = 10Gi


• Attached to AKS node

AKS automatically:

• Created disk


• Attached it


• Mounted it


• Bound PVC to Pod

Step 8️⃣ — Test Persistence

Enter PostgreSQL:

kubectl exec -it postgres-0 -n postgres-demo -- psql -U postgres

Create database:

CREATE DATABASE demo;

Now delete pod:

kubectl delete pod postgres-0 -n postgres-demo

Wait for restart:

kubectl rollout status statefulset/postgres -n postgres-demo

Verify:

kubectl exec -it postgres-0 -n postgres-demo -- psql -U postgres -l

You should still see:

demo

✅ Data persisted

✅ Disk reattached automatically

✅ No data loss

🔍 What This Demonstrates

🏆 Production Improvements

For real workloads, add:

• Resource limits


• Liveness/readiness probes


• PodDisruptionBudget


• Anti-affinity rules


• Replica for HA


• Backup strategy (Velero or Azure Backup)


• Monitoring (Azure Monitor / Prometheus)

🎯 Final Architecture

PostgreSQL (StatefulSet)

↓

PVC (RWO)

↓

Azure Managed Disk (Premium SSD)

↓

Zone-aware AKS node

🚀 When to Use This Pattern

Use PostgreSQL on AKS if:

• You need full control


• You want per-tenant DB isolation


• You want environment parity (dev → prod)


• You’re building platform-level tooling

Use managed DB service instead if:

• You want automatic patching


• You want built-in HA


• You don’t want operational overhead

🔚 Conclusion

You’ve now:

✔ Deployed PostgreSQL on AKS

✔ Used Azure Premium SSD

✔ Configured StatefulSet properly

✔ Solved lost+found issue

✔ Verified data persistence

This is the foundation of running stateful workloads on AKS safely and correctly.