Simple CRM 📊

A lightweight Customer Relationship Management system for managing sellers and their transactions.

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Features

• Seller & Transaction Management: Create, retrieve, update, soft-delete, and hard-delete sellers and transactions.
• Analytics:
  • Identify the top seller within a given period.
  • Find sellers with a turnover below a specified amount.
• Data History Preservation:
  • Versioning of database records for Update operations.
  • Delete Types:
    • Soft-delete: Records are marked as deleted but remain in the database.
    • Hard-delete: Records are permanently removed from the database.

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Technology Stack

Backend

• Java 21 (Gradle)
• Spring Boot 3.4+ (Data JPA, WebMVC, Test)
• PostgreSQL 12+ — primary database
• Flyway — database migration management
• H2 — in-memory database for integration testing
• SwaggerUI (OpenAPI) — automatic API documentation
• Spring Boot Test (JUnit 5 + Mockito) — unit and integration testing
• Lombok

Tools

• Gradle — build and dependency management
• Postman — manual API testing and debugging

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Build and Run Instructions

Prerequisites

• Java 21
• Gradle 8.0+
• PostgreSQL 12+

Database Setup

1. Create a PostgreSQL database, e.g. simple_crm_db.
2. Ensure the user has read/write permissions.

Application Configuration

1. Create a .env file under the Presentation/.env directory.
2. Configure your database connection according to the example in .env.example.
3. Create a gradle.properties file in the project root.
4. Configure Flyway settings based on gradle.properties.example.
5. Verify the configured data source in your IDE.

Build the Project and Run Database Migrations

# Stop all running Spring Boot processes (if any)
taskkill /f /im java.exe

# Clean and build the project
./gradlew clean build --refresh-dependencies

# Run Flyway migrations
./gradlew :Presentation:flywayClean :Presentation:flywayMigrate

# Start the application
./gradlew :Presentation:bootRun

Warning

Flyway rollbacks are available only in the Pro or Enterprise editions. If you encounter migration issues (missing tables, invalid flyway_schema_history, etc.), manually recreate the necessary tables using PgAdmin or your IDE’s SQL console.

If the build succeeds, the application will be available at: http://localhost:8080

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API Examples

Request:

POST http://localhost:8080/api/sellers
Content-Type: application/json

{
    "name": "John Doe",
    "contactInfo": "john.doe@example.com",
    "registrationDate": "2025-10-07T12:30:00"
}

Response:

201 Created
{
    "seller": {
        "id": 1,
        "name": "John Doe",
        "contactInfo": "john.doe@example.com",
        "registrationDate": "2025-10-10T19:46:19.7552163",
        "version": null
    },
    "message": null,
    "errorType": null
}

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Request:

DELETE http://localhost:8080/api/transactions/1?deleteType=soft

Response:

204 No Content

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Request:

GET http://localhost:8080/api/analytics/best-period/1
Content-Type: application/json
{
  "amount": 65.05,
  "paymentType": "CASH",
  "transactionDate" : "2025-09-07T14:00:00",
  "sellerId": 1
}

Response:

200 OK
{
    "startDate": "2025-06-07T14:00:00",
    "endDate": "2025-10-07T14:00:00",
    "transactionCount": 3
}

Once the application is running, the full API specification is available at: http://localhost:8080/swagger-ui/index.html

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Testing

• Unit Tests for entities, DTOs, services, and utilities. Average coverage: 90%
• API Tests covering all main usage scenarios.
• Integration Tests for repositories using an H2 in-memory database.

Run All Tests:

# run tests
./gradlew test

Generate coverage report with JaCoCo

# generate JaCoCo coverage reports
./gradlew jacocoRootReport

Code coverage reports are available at: build/reports/jacoco/rootHtml/index.html

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Docker Deployment

The application can be easily deployed using Docker with the provided Dockerfile and docker-compose.yaml configuration files.

Prerequisites for Docker Deployment

• Docker Engine 20.10+
• Docker Compose v2.0+

Quick Start with Docker Compose

1. Create a .env file in the project root directory with your database credentials:

   DB_USER=postgres
   DB_PASSWORD=your_secure_password
   DB_URL=jdbc:postgresql://db:5432/SimpleCrmDb

2. Build and start the services:

   # Build the Docker images
   docker-compose build
   
   # Start all services
   docker-compose up -d

3. Access the application: Once the containers are running, the application will be available at: http://localhost:8080

Docker Configuration Files

• Dockerfile: Multi-stage build configuration for the Spring Boot application with security best practices
• docker-compose.yaml: Production-ready configuration with environment variables and resource limits
• docker-compose.override.yaml: Development configuration with volume mounts for live code reloading

Environment Variables

The Docker deployment uses the following environment variables (can be set in .env file):

• DB_NAME: Database name (default: SimpleCrmDb)
• DB_USER: Database username
• DB_PASSWORD: Database password
• DB_PORT: Database port (default: 5432)
• APP_PORT: Application port (default: 8080)
• SPRING_PROFILES_ACTIVE: Spring profile to use (default: docker)

Useful Docker Commands

# View container logs
docker-compose logs -f

# Stop all services
docker-compose down

# View running containers
docker-compose ps

# Execute commands in the running container
docker-compose exec app bash

Security Features

• Runs application with non-root user
• Resource limits to prevent DoS attacks
• Health checks for service monitoring
• Environment variables for secret management
• Minimal base images to reduce attack surface

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License

This project is licensed under the MIT License - see the LICENSE.md file for details.

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Contact

For questions or feedback: limosha@inbox.ru

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