Building an LLM Chat Application
We walk through building a modern AI chat application that supports both OpenAI and local LLM models, with Kubernetes deployment and GPU acceleration.
Table of Contents
Project Overview
Our AI chat application is a full-stack solution that demonstrates modern software development practices:
- Multiple LLM Support: Integration with OpenAI’s GPT models and local models using vLLM
- Microservices Architecture: Separate services for frontend, backend, and inference
- Container Orchestration: Kubernetes deployment with GPU support
- CI/CD Pipeline: Automated testing and deployment using GitHub Actions
Architecture
Components
- Frontend (Streamlit)
- Modern chat interface
- Real-time response streaming
- Model selection and configuration
- Backend (FastAPI)
- API gateway
- Request routing
- Model management
- Inference Service (vLLM)
- GPU-accelerated inference
- Model loading and caching
- Efficient resource utilization
Infrastructure
graph TD
A[User] --> B[Frontend Service]
B --> C[Backend Service]
C --> D[OpenAI API]
C --> E[Inference Service]
E --> F[GPU Resources]
Development Setup
Prerequisites
- Python 3.10+
- Docker
- Kubernetes cluster
- NVIDIA GPU with drivers
Local Development
- Clone the Repository
git clone https://github.com/yourusername/ai-chat.git cd ai-chat
- Set Up Environment
python -m venv venv source venv/bin/activate pip install -r requirements.txt
- Run Services
# Terminal 1 - Backend cd backend && uvicorn main:app --reload # Terminal 2 - Frontend cd frontend && streamlit run app.py # Terminal 3 - Inference cd inference && uvicorn main:app --reload
Kubernetes Deployment
Cluster Setup
- Enable GPU Support
# Install NVIDIA device plugin kubectl create -f https://raw.githubusercontent.com/NVIDIA/k8s-device-plugin/master/nvidia-device-plugin.yml
- Create Namespace
kubectl create namespace ai-chat
- Apply Configurations
kubectl apply -f k8s/configmap.yaml kubectl apply -f k8s/pvc.yaml kubectl apply -f k8s/backend-deployment.yaml kubectl apply -f k8s/frontend-deployment.yaml kubectl apply -f k8s/inference-deployment.yaml
Resource Management
- GPU allocation through Kubernetes device plugins
- Persistent volume for model storage
- Resource limits and requests for each service
CI/CD Pipeline
GitHub Actions Workflow
- Build and Test
- Run unit tests
- Build Docker images
- Push to container registry
- Deploy
- Update Kubernetes manifests
- Apply configurations
- Verify deployment
Security Considerations
- Secrets management
- Image scanning
- Access control
Best Practices
Development
- Code Organization
- Modular architecture
- Clear separation of concerns
- Comprehensive testing
- Performance
- Efficient resource utilization
- Caching strategies
- Load balancing
- Security
- API key management
- Input validation
- Error handling
Deployment
- Monitoring
- Health checks
- Resource usage
- Error tracking
- Scaling
- Horizontal pod autoscaling
- Resource optimization
- Load distribution
- Maintenance
- Regular updates
- Backup strategies
- Disaster recovery
Conclusion
This project demonstrates how to build and deploy a modern AI application using best practices in software development and DevOps. The combination of microservices architecture, container orchestration, and GPU acceleration provides a scalable and efficient solution for AI-powered applications.