Deploying PostgreSQL with Kubernetes

PostgreSQL is a powerful database and we can scale it easy with Kubernetes

In this case we gonna use Kubernetes to store our pods of Postgres with a data value external because if we any pod stop accidentally we won’t lose our data.

Configuring our Storageclass

kind: StorageClassapiVersion: storage.k8s.io/v1metadata:  namespace: kube-system  name: standard  annotations:    storageclass.kubernetes.io/is-default-class: "true"  labels:    addonmanager.kubernetes.io/mode: EnsureExistsprovisioner: k8s.io/minikube-hostpath

Now we gonna configure our Persistent Volume with 5GB to store our data locally (path var/data), enabling just one pod access it par time.

kind: PersistentVolumeapiVersion: v1metadata:  name: postgres-pv  labels:    app: postgres    type: localspec:  storageClassName: standard  capacity:    storage: 5Gi  accessModes:    - ReadWriteOnce  hostPath:    path: "/var/data"----kind: PersistentVolumeClaimapiVersion: v1metadata:  name: postgres-pv-claim  labels:    app: postgresspec:  storageClassName: standard  capacity:  accessModes:    - ReadWriteOnce  resources:    requests:      storage: 5Gi

Let’s configure our Configmap with the data to access our DB

apiVersion: v1kind: ConfigMapmetadata:  name: postgres-configuration  labels:    app: postgresdata:  POSTGRES_DB: awesomedb  POSTGRES_USER: amazinguser  POSTGRES_PASSWORD: perfectpassword

Now let’s order 3 instances of our DB PostgreSQL 13

apiVersion: apps/v1kind: StatefulSetmetadata:  name: postgres-statefulset  labels:    app: postgresspec:  serviceName: "postgres"  replicas: 3  selector:    matchLabels:      app: postgres  template:    metadata:      labels:        app: postgres    spec:      containers:      - name: postgres        image: postgres:13        envFrom:        - configMapRef:            name: postgres-configuration        ports:        - containerPort: 5432          name: postgresdb        volumeMounts:        - name: pv-data          mountPath: /var/lib/postgresql/data      volumes:      - name: pv-data        persistentVolumeClaim:          claimName: postgres-pv-claim

Finally let’s create a service to enable our DB be accessible

apiVersion: v1kind: Servicemetadata:  name: postgres-service  labels:    app: postgresspec:  ports:  - port: 5432    name: postgres  type: NodePort   selector:    app: postgres

Good! now we already have our yaml ready to be installed! so let’s do it!

kubectl apply -f k8s_postgres_13.yaml

If everything is good we can check our BD running:

kubectl get pods

Voila! our PostgreSQL is installed and running on Kubernetes! let’s test it!

kubectl port-forward postgres-service 5432:5432

Good! you can use your client preferred to use your PostgreSQL!

The file YAML complete: https://github.com/rondweb/kubernetes/blob/main/postgres/k8s_postgres_13.yaml