Comprehensive Guide to Zalando PostgreSQL Operator

Using Zalando PostgreSQL Operator

The Zalando PostgreSQL Operator is a Kubernetes operator designed to simplify the management of PostgreSQL clusters. Developed by Zalando, this operator automates critical database operations such as provisioning, backups, scaling, and failover, allowing teams to focus on application development rather than database maintenance.

Key Features

1. Cluster Automation: Handles PostgreSQL cluster creation and management.

2. High Availability: Provides automatic failover and load balancing.

3. Backup and Restore: Simplifies regular backups and recovery processes.

4. Scaling: Supports horizontal and vertical scaling.

5. Security: Integrates with Kubernetes secrets for secure credential management.

Installation

Prerequisites:

• Kubernetes cluster
• kubectl configured for the cluster

1. Add the Helm repository:

helm repo add zalando https://opensource.zalando.com/postgres-operator/charts/postgres-operator
helm repo update

2. Install the PostgreSQL Operator:

helm install postgres-operator zalando/postgres-operator

Syntax for Cluster Definition

The operator uses a YAML manifest to define PostgreSQL clusters. Below is a sample configuration:

apiVersion: "acid.zalan.do/v1"
kind: postgresql
metadata:
  name: my-postgres-cluster  # Name of the cluster
  namespace: default         # Namespace in Kubernetes
spec:
  teamId: "my-team"          # Team owning the cluster
  volume:
    size: 10Gi               # Disk size
  numberOfInstances: 3       # Number of PostgreSQL instances
  users:
    admin:                   # User roles
      - superuser
      - createdb
  databases:
    mydb: admin              # Database and its owner
  postgresql:
    version: "14"            # PostgreSQL version

Example 1: Deploying a PostgreSQL Cluster

1. Apply the YAML manifest:

kubectl apply -f postgres-cluster.yaml

2. Verify the Cluster:

kubectl get pods -l application=spilo

Explanation:

• This deploys a 3-node PostgreSQL cluster.
• Users and roles are predefined, with admin as the superuser.

Example 2: Enabling Backups

Configure backups using S3 storage in the operator configuration:

spec:
  enableLogicalBackup: true
  backup:
    s3_bucket: "my-s3-bucket"
    s3_region: "us-east-1"
    s3_endpoint: "https://s3.amazonaws.com"

steps:

1. Update the YAML file with S3 credentials.

2. Apply the changes:

kubectl apply -f postgres-cluster.yaml

Explanation: This enables automated logical backups stored in an S3-compatible storage service.

Monitoring with Metrics

The operator integrates with Prometheus to monitor PostgreSQL metrics.

1. Install Prometheus in the Kubernetes cluster.

2. Use the metrics endpoint provided by the Zalando operator:

     kubectl port-forward svc/postgres-operator 8080:8080
	 

3. Access metrics at http://localhost:8080/metrics.

Best Practices:

1. Namespace Isolation: Deploy PostgreSQL clusters in isolated namespaces.

2. Regular Backups: Enable and verify backup mechanisms.

3. Resource Limits: Define resource requests and limits for predictable scaling.

4. Security: Use Kubernetes secrets for sensitive data like passwords.

Common Issues

• Insufficient Permissions: Ensure proper RBAC configuration for the operator.
• Storage Limitations: Allocate adequate disk space for databases.
• Cluster Scaling Issues: Monitor resource utilization to avoid bottlenecks.

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