Database operators example in Kubernetes - Mini Project: Build & Apply

Database Operators Example with Kubernetes

📖 Scenario: You are working as a DevOps engineer managing a Kubernetes cluster. Your team wants to deploy a PostgreSQL database using a Kubernetes Operator to simplify management tasks like backups and scaling.

🎯 Goal: Learn how to deploy a PostgreSQL database using a Kubernetes Operator by creating the necessary Kubernetes manifests step-by-step.

📋 What You'll Learn

Create a namespace for the database operator

Deploy the PostgreSQL Operator in the namespace

Create a PostgreSQL cluster custom resource

Verify the PostgreSQL pods are running

💡 Why This Matters

🌍 Real World

Kubernetes Operators automate complex application management tasks like deploying and managing databases in cloud environments.

💼 Career

DevOps engineers and SREs use Operators to simplify database lifecycle management, improving reliability and reducing manual work.

1

Create a namespace for the PostgreSQL Operator

Write a YAML manifest to create a Kubernetes namespace called postgres-operator. Use the apiVersion v1 and kind Namespace.

Kubernetes

# Write the YAML manifest to create the namespace
# Your code here

Need a hint?

Namespaces isolate resources in Kubernetes. Use apiVersion: v1 and kind: Namespace with metadata name.

2

Deploy the PostgreSQL Operator in the namespace

Write a YAML manifest to deploy the PostgreSQL Operator as a Deployment named postgres-operator in the postgres-operator namespace. Use apps/v1 for apiVersion and specify 1 replica. Use the container image postgres-operator:latest.

Kubernetes

apiVersion: v1
kind: Namespace
metadata:
  name: postgres-operator

# Write the Deployment manifest for postgres-operator
# Your code here

Need a hint?

Deployments manage pods. Use apps/v1 apiVersion, set replicas to 1, and specify the container image.

3

Create a PostgreSQL cluster custom resource

Write a YAML manifest for a PostgreSQL cluster custom resource named example-cluster in the postgres-operator namespace. Use apiVersion: postgres-operator.crunchydata.com/v1beta1 and kind: PostgresCluster. Set instances replicas to 1 and image to postgres:14.

Kubernetes

apiVersion: v1
kind: Namespace
metadata:
  name: postgres-operator
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres-operator
  namespace: postgres-operator
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgres-operator
  template:
    metadata:
      labels:
        app: postgres-operator
    spec:
      containers:
      - name: postgres-operator
        image: postgres-operator:latest

# Write the PostgresCluster custom resource manifest
# Your code here

Need a hint?

Custom resources define the database cluster. Use the correct apiVersion and kind, set replicas and image as specified.

4

Verify the PostgreSQL pods are running

Run the command kubectl get pods -n postgres-operator to list pods in the postgres-operator namespace. Confirm that the pod for example-cluster is in the Running state.

Kubernetes

apiVersion: v1
kind: Namespace
metadata:
  name: postgres-operator
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres-operator
  namespace: postgres-operator
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgres-operator
  template:
    metadata:
      labels:
        app: postgres-operator
    spec:
      containers:
      - name: postgres-operator
        image: postgres-operator:latest
---
apiVersion: postgres-operator.crunchydata.com/v1beta1
kind: PostgresCluster
metadata:
  name: example-cluster
  namespace: postgres-operator
spec:
  instances:
  - replicas: 1
  image:
    name: postgres:14

# Run the command below to check pods
# Your code here

Need a hint?

Use kubectl get pods -n postgres-operator to see pods and their status.