SilverBank

A full-stack banking application built as the target workload for a DevOps capstone project. SilverBank provides core personal finance features — account management, transactions, money transfers, and cash tracking — and serves as a realistic 3-tier application to demonstrate a production-grade CI/CD ecosystem.

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Table of Contents

• Purpose
• Features
• Tech Stack
• Architecture
• API Reference
• Database Schema
• Running Locally
• Testing
• Environment Variables
• CI/CD Integration

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Purpose

SilverBank was built specifically for the DevOps Final Project capstone. The application itself is intentionally straightforward — the primary objective is not the application code, but the infrastructure and delivery pipeline surrounding it.

The app provides a realistic workload with:

• A stateful backend requiring a persistent database
• JWT-based authentication requiring secure secret management
• Multi-tier architecture (frontend / backend / database) that exercises real deployment complexity
• A health endpoint that exposes deployment metadata for monitoring and rollback automation

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Features

• User registration and login — JWT authentication via HTTP-only cookies
• Bank account management — auto-generated IBAN, balance tracking
• Transactions — deposit, withdrawal, and transfer history
• Money transfers — send money between accounts
• Cash tracker — personal expense tracking with categories
• Welcome bonus — automatically credited on first login
• Health endpoint — returns status, database connection, environment, and image tag

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Tech Stack

Layer	Technology
Frontend	Next.js 16 (React, TypeScript, Tailwind CSS)
Backend	Express.js (TypeScript)
ORM	Prisma
Database	PostgreSQL 16
Auth	JWT (jsonwebtoken + bcryptjs)
Testing	Vitest

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Architecture

SilverBank runs as three separate containers:

┌─────────────────────────────────────────────────┐
│                   Nginx (edge)                  │
│   /api/*  →  backend  :4000                     │
│   /*      →  frontend :3000                     │
└──────────────┬──────────────────────────────────┘
               │
       ┌───────┴────────┐
       ▼                ▼
┌─────────────┐  ┌─────────────┐
│  frontend   │  │   backend   │
│  Next.js    │  │  Express.js │
│  :3000      │  │  :4000      │
└─────────────┘  └──────┬──────┘
                        │
                        ▼
                ┌──────────────┐
                │  PostgreSQL  │
                │  :5432       │
                └──────────────┘

On production (Proxmox), the database runs on a dedicated VM (db-postgresql). On staging, all three tiers run as local containers on the same VM using docker-compose.staging.yml.

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API Reference

Authentication — /api/auth

Method	Endpoint	Description	Auth
POST	/api/auth/register	Create new user account	No
POST	/api/auth/login	Login and receive JWT cookie	No
POST	/api/auth/logout	Clear JWT cookie	Yes
DELETE	/api/auth/delete	Delete authenticated user	Yes

Account — /api/account

Method	Endpoint	Description	Auth
GET	/api/account	Get account details and balance	Yes
POST	/api/account/transfer	Transfer money to another account	Yes
POST	/api/account/loan	Request a loan	Yes
DELETE	/api/account/close	Close account	Yes

Transactions — /api/transactions

Method	Endpoint	Description	Auth
GET	/api/transactions	Get transaction history	Yes

Cash Tracker — /api/cash

Method	Endpoint	Description	Auth
GET	/api/cash	Get all cash entries	Yes
POST	/api/cash	Add a cash entry	Yes
DELETE	/api/cash/:id	Delete a cash entry	Yes

Health — /api/health

Method	Endpoint	Description	Auth
GET	/api/health	Application and database status	No

{
  "status": "ok",
  "timestamp": "2026-03-23T21:19:12.526Z",
  "database": "connected",
  "version": "1.0.0",
  "environment": "blue",
  "image_tag": "v1.0-sha-abc1234"
}

The environment and image_tag fields are injected at deploy time via environment variables — they are used by the CI/CD pipeline for rollback monitoring and by Prometheus for deployment traceability.

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Database Schema

User
  ├── id, email (unique), password (bcrypt), name
  ├── bonusGranted (Boolean)
  ├── accounts   → Account[]
  └── cashEntries → CashEntry[]

Account
  ├── id, iban (unique), balance, bonusGranted
  ├── userId → User
  └── transactions → Transaction[]

Transaction
  ├── id, type, amount, description
  ├── createdAt
  └── accountId → Account

CashEntry
  ├── id, description, amount, category
  ├── createdAt
  └── userId → User

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Running Locally

Prerequisites

• Node.js 20+
• PostgreSQL 16 (or use Docker Compose)
• npm

Setup

# Clone the repository
git clone https://github.com/mariusiordan/SilverBank-App.git
cd SilverBank-App/silver-bank

# Install dependencies
npm install

# Start local database (PostgreSQL + backend + frontend)
docker compose up -d

# Apply database migrations
cd backend
npx prisma migrate deploy
npx prisma generate

# Start development server
cd ..
npm run dev

The application will be available at http://localhost:3000.

Docker Compose (local)

# Start all services
docker compose up -d

# Stop all services
docker compose down

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Testing

Tests are written with Vitest and cover JWT token handling, authentication flows, and account management.

cd silver-bank

# Run all tests
npx vitest run

# Run specific test suite
npx vitest run __tests__/jwt.test.ts
npx vitest run __tests__/login.test.ts
npx vitest run __tests__/register.test.ts
npx vitest run __tests__/account.test.ts

# Run with coverage
npx vitest run --coverage

Auth and Account tests require a running database. In CI, they run inside a Docker container to ensure a consistent environment.

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Environment Variables

Variable	Description	Example
DATABASE_URL	PostgreSQL connection string	postgresql://user:pass@host:5432/appdb
JWT_SECRET	Secret key for JWT signing	K7x9mN2pQrL5vB8w...
PORT	Backend server port	4000
FRONTEND_URL	Allowed CORS origin	http://localhost:3000
DEPLOY_ENV	Active Blue/Green environment	blue or green
IMAGE_TAG	Docker image tag for this deployment	v1.0-sha-abc1234

DEPLOY_ENV and IMAGE_TAG are injected automatically by Ansible at deploy time — they are surfaced via /api/health and used by the rollback monitor.

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CI/CD Integration

SilverBank is deployed through a three-pipeline CI/CD ecosystem defined in .github/workflows/:

Pipeline	File	Trigger	Purpose
CI	test.yml	Pull Request	Lint + parallel unit tests + PR comment on failure
Staging	staging.yml	Push to staging	Build images, deploy to staging, integration tests
Production	deploy.yml	Push to main	Promote image, manual approval, Blue/Green deploy

Image Tags

Images are tagged as v{MAJOR}.{MINOR}-sha-{git-sha} — no dates, no rebuilds between environments. The same image built on staging is promoted to production unchanged.

v1.0-sha-abc1234   ← staging build
        │
        ▼ promote (retag, no rebuild)
v1.0-sha-abc1234   ← production deploy
        │
        ▼ after 10-minute health check
:latest            ← AWS DR pulls this tag

For full infrastructure documentation, see the infrastructure repository.