Building a Mini DBaaS with Kubernetes in One Week - Part 1: Architecture Overview

Introduction

Ever wondered how cloud database services like AWS RDS or Google Cloud SQL work under the hood? What if you could build your own Database-as-a-Service (DBaaS) platform using Kubernetes? In this series, I'll show you how to create a fully functional mini DBaaS platform in just one week using Node.js and Kubernetes.

By the end of this series, you'll have a working DBaaS that can:

Create and manage PostgreSQL, MySQL, and MariaDB instances
Provide high-availability PostgreSQL clusters with automatic failover
Offer Aurora-style backup and recovery using CSI VolumeSnapshots
Support multi-tenant isolation with namespaces
Monitor database health and performance

Why Build Your Own DBaaS?

Building a DBaaS might seem like overkill for small projects, but it's an excellent way to:

Learn Kubernetes deeply: Understand StatefulSets, PVCs, Operators, and more
Master cloud-native patterns: Experience real-world distributed systems
Gain DevOps skills: Practice infrastructure as code with Helm charts
Understand database operations: Learn about backup strategies, high availability, and monitoring

Our Architecture Overview

Our mini DBaaS follows a clean, layered architecture:

┌─────────────────────────────────────┐
│         User Requests (CLI/API)     │
└──────────────┬──────────────────────┘
               ↓
┌─────────────────────────────────────┐
│      Node.js API Server (Express)   │
│  • Instance CRUD operations         │
│  • Helm chart deployment            │
│  • Kubernetes resource management   │
└──────────────┬──────────────────────┘
               ↓
┌─────────────────────────────────────┐
│        Kubernetes (minikube)        │
│  ┌────────────────────────────────┐ │
│  │  Namespace per instance        │ │
│  │  StatefulSet + PVC (DB Pod)    │ │
│  │  Secret, ConfigMap             │ │
│  └────────────────────────────────┘ │
└──────────────┬──────────────────────┘
               ↓
┌─────────────────────────────────────┐
│    Local Storage (PVC, HostPath)    │
│  • MySQL/MariaDB/PostgreSQL data    │ │
└──────────────┬──────────────────────┘
               ↓
┌─────────────────────────────────────┐
│    CSI VolumeSnapshot Backup        │
│  • Aurora-style point-in-time       │ │
│  • 5-10 second snapshot creation    │ │
│  • 30-second recovery time          │ │
└──────────────┬──────────────────────┘
               ↓
┌─────────────────────────────────────┐
│  PostgreSQL HA (Zalando Operator)   │
│  • Automatic failover               │ │
│  • Read/write load balancing        │ │
│  • 3-5 node clusters                │ │
└─────────────────────────────────────┘

Technology Stack

We'll use a modern, cloud-native stack:

Backend: Node.js with Express (lightweight and fast)
Orchestration: Kubernetes with Helm (industry standard)
Databases: PostgreSQL, MySQL, MariaDB via Bitnami charts
High Availability: Zalando PostgreSQL Operator
Backup/Recovery: CSI VolumeSnapshots (like AWS Aurora)
Storage: PVC with hostPath (minikube) / cloud storage (production)
Monitoring: Real-time pod/helm status tracking

Key Features We'll Implement

1. Multi-Database Support

PostgreSQL, MySQL, and MariaDB instances
Custom Helm charts for each database type
Automatic configuration and secret management

2. High Availability Clusters

PostgreSQL HA using Zalando PostgreSQL Operator
Automatic failover and load balancing
Master/Replica service separation

3. Aurora-Style Backup System

CSI VolumeSnapshot for storage-level backups
Point-in-time recovery
Cross-instance backup restoration

4. Multi-Tenant Isolation

Namespace-based resource isolation
Independent storage volumes per tenant
Resource quotas and limits

5. RESTful API

Complete CRUD operations for instances
Real-time status monitoring
Connection information retrieval

Development Timeline

Here's our one-week development plan:

Day	Focus	Deliverables
Day 1	Environment Setup & Basic API	Node.js server, basic routes
Day 2	Kubernetes Integration	Helm charts, basic deployment
Day 3	Database Instance Management	Create/delete/status APIs
Day 4	Backup & Recovery System	CSI VolumeSnapshots
Day 5	High Availability Clusters	Zalando PostgreSQL Operator
Day 6	Multi-Tenant Features	Namespace isolation, quotas
Day 7	Testing & Documentation	API testing, deployment guide

What You'll Learn

Throughout this series, you'll gain hands-on experience with:

Kubernetes StatefulSets: Managing stateful applications
Persistent Volume Claims: Database storage management
Helm Charts: Package and deploy applications
Kubernetes Operators: Advanced application management
CSI VolumeSnapshots: Storage-level backup strategies
Multi-tenancy: Resource isolation and management
API Design: RESTful service architecture

Prerequisites

Before we start, make sure you have:

Docker Desktop installed and running
minikube for local Kubernetes cluster
Helm for package management
Node.js (v18+) for the API server
kubectl for Kubernetes interaction

Next Steps

In the next post, we'll set up our development environment and create the basic Node.js API server structure. We'll start with the foundation and gradually build up to a fully functional DBaaS platform.

Are you ready to build your own cloud database service? Let's dive in! 🚀

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