Libernetix S2S Payment Processing Example

This is a simple example of a payment processing (server-to-server) system built with Angular and NestJS which integrates with Libernetix API.

Libernetix API: https://gate.libernetix.com/api

Features

• Payment processing with 3D Secure support
• Real-time payment status tracking
• Health monitoring and metrics
• OpenTelemetry integration
• RabbitMQ message queue integration
• MongoDB database
• End-to-end testing with Cypress
• Performance testing with k6

Tech Stack

Web Application (Frontend)

• Framework: Angular
• Design: Taiga UI
• Testing: Vitest (unit)
• Code Quality: ESLint, Prettier

Server Application (Backend)

• Framework: NestJS
• Database: MongoDB
• Message Queue: RabbitMQ
• Testing: Vitest (unit & integration), Nock (mocking HTTP requests)
• Monitoring: OpenTelemetry
• Code Quality: ESLint, Prettier

Moonrepo

• Build orchestration and task caching for faster development

Monitoring

• Metrics: Prometheus
• Tracing: Jaeger (UI: http://localhost:16686)

Project Structure

/ libernetix-s2s-example
├── apps/
│   ├── web/            # Angular frontend application
│   └── server/         # NestJS backend application
├── packages/
│   ├── eslint-config/  # Shared ESLint configuration
│   └── vitest/         # Shared Vitest configuration
├── e2e/                # End-to-end tests with Cypress
└── infra/              # Infrastructure configuration
    ├── mongodb/        # MongoDB configuration
    ├── rabbit/         # RabbitMQ configuration
    └── monitoring/     # Monitoring stack configuration

Getting Started

To get started, you'll need Moonrepo installed globally. Moonrepo will automatically install all required dependencies.

Prerequisites

Before setting up the project, you'll need Moonrepo installed. You have several options to install it:

Using proto (recommended):

proto plugin add moon "https://raw.githubusercontent.com/moonrepo/moon/master/proto-plugin.toml" --to global
proto install moon

Using npm:

npm install --save-dev @moonrepo/cli

On Linux, macOS, or WSL:

curl -fsSL https://moonrepo.dev/install/moon.sh | bash

Then add to your PATH:

export PATH="$HOME/.moon/bin:$PATH"

On Windows (PowerShell):

irm https://moonrepo.dev/install/moon.ps1 | iex

For more detailed information about Moonrepo installation and usage, refer to the official Moonrepo Documentation.

Running the Applications

Once Moonrepo is installed, you can easily manage the frontend and backend applications using the following commands:

• Web Application:

  moon web:start       # Starts the web application locally
  moon web:test        # Runs unit and integration tests
  moon web:build       # Builds the web application for production

• Server Application:

  moon server:start    # Starts the server locally
  moon server:test     # Runs unit, integration, and contract tests
  moon server:build    # Builds the server for production

  Environment variables:

  PORT=3000 # The port the server will listen on
  SELF_URL=http://localhost:3000 # The URL of the server
  
  SERVICE_NAME=my-server # The name of the service
  OTLP_EXPORTER_URL=http://localhost:4318 # The URL of the OTLP exporter
  JAEGER_UI_URL=http://localhost:16686 # The URL of the Jaeger UI
  
  RMQ_URL=amqp://localhost:5672 # The URL of the RabbitMQ server
  RMQ_METRICS_URL=http://localhost:15692/metrics # The URL of the RabbitMQ metrics
  
  MONGO_URI=mongodb://localhost:27017/s2s # The URL of the MongoDB server
  
  API_URL=https://gate.example.com/api # The URL of the Libernetix API
  API_KEY= # The API key for the Libernetix API
  BRAND_ID= # The brand ID for the Libernetix API
  S2S_TOKEN= # The S2S token for the Libernetix API
  
  UI_URL=http://localhost:4200 # The URL of the frontend application

  Note: To run Webhook server, you need to expose the server to the internet. You can use moon server:expose command to expose the server and update the API_URL environment variable to the public URL of the server.

• End-to-end testing:

  moon e2e:test      # Runs the end-to-end tests
  moon e2e:test-ui   # Runs the end-to-end tests in UI mode

Payment Flow

Not enrolled in 3D Secure

sequenceDiagram 
  participant Client
  participant Frontend
  participant Backend
  participant RabbitMQ
  participant Libernetix

  Client->>Frontend: Initiate Payment
  Frontend->>Backend: POST /payments
  Backend->>Libernetix: POST /purchases/
  Libernetix->>Backend: 
  Backend->>RabbitMQ: Publish payment.process
  Backend->>Frontend: Purchase ID
  Frontend->>Backend: SSE /:purchaseId/events
  Frontend->>Frontend: Navigate to Processing Page
  RabbitMQ->>Backend: Consume payment.process
  Backend->>Libernetix: POST <direct_post_url>?s2s=true
  Libernetix->>Backend: 
  Backend->>Backend: Handle Payment Status
  Backend->>RabbitMQ: Publish payment.update-status
  RabbitMQ->>Backend: Consume payment.update-status
  Backend->>Frontend: SSE /:purchaseId/events (Payment Executed/Failed)
  Frontend->>Frontend: Navigate to Status Page

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Enrolled in 3D Secure

sequenceDiagram 
  participant Client
  participant Frontend
  participant Backend
  participant RabbitMQ
  participant Libernetix
  participant Database
  participant Bank

  Client->>Frontend: Initiate Payment
  Frontend->>Backend: POST /payments
  Backend->>Libernetix: POST /purchases/
  Libernetix->>Backend: 
  Backend->>RabbitMQ: Publish payment.process
  Backend->>Frontend: Purchase ID
  Frontend->>Backend: SSE /:purchaseId/events
  Frontend->>Frontend: Navigate to Processing Page
  RabbitMQ->>Backend: Consume payment.process
  Backend->>Libernetix: POST <direct_post_url>?s2s=true
  Libernetix->>Backend: 
  Backend->>Backend: Handle Payment Status
  Backend->>Database: Save callback_url
  Backend->>RabbitMQ: Publish payment.update-status
  RabbitMQ->>Backend: Consume payment.update-status
  Backend->>Frontend: SSE /:purchaseId/events (3D)
  Frontend->>Bank: Send 3D Secure request
  Bank->>Backend: POST /:purchaseId/callback
  Database->>Backend: Find callback_url
  Backend->>Database: 
  Backend->>Libernetix: Send 3D Secure request
  Libernetix->>Backend: 
  Backend->>Backend: Handle Payment Status
  Backend->>RabbitMQ: Publish payment.update-status
  RabbitMQ->>Backend: Consume payment.update-status
  Backend->>Frontend: SSE /:purchaseId/events (Payment Executed/Failed)
  Frontend->>Frontend: Navigate to Status Page

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Monitoring & Health Checks

Health Endpoints

To monitor the health of the server application, you can use the following endpoints:

• GET /health - Detailed health status
• GET /liveness - Basic liveness probe
• GET /readiness - Application readiness status

Metrics & Tracing

The application uses OpenTelemetry for:

• Distributed tracing
• Metrics collection
• Performance monitoring

Security Features

• Helmet for secure HTTP headers
• Rate limiting protection
• Request signature validation (Webhooks)
• CORS configuration

License

This project is licensed under the Apache License 2.0. See the LICENSE file for more information.