# Feature: Infrastructure Setup

> **Status**: ⏳ Planned  
> **Priority**: High  
> **Complexity**: Medium  
> **Estimate**: 10-14 hours  
> **Assignee**: -  
> **Created**: May 31, 2025  
> **Target Completion**: -  
> **Related Features**: All other features depend on this

---

## 📌 Overview

### Purpose
Establish the foundational infrastructure for the DeutschLernen application, including backend project, database, and core dependencies.

### User Story
As a developer, I want to have a working backend and database setup so that I can begin implementing application features.

### Acceptance Criteria
- [ ] .NET 9.0 backend project is created and builds successfully
- [ ] PostgreSQL database is configured and accessible
- [ ] Docker setup is ready for deployment
- [ ] CI/CD pipeline is configured
- [ ] Development environment is reproducible

---

## 📋 Requirements

### Functional Requirements
| ID | Requirement | Priority |
|----|-------------|----------|
| FR-001 | .NET 9.0 backend with ASP.NET Core Web API | High |
| FR-002 | PostgreSQL database with connection string configuration | High |
| FR-003 | Docker containers for backend and database | High |
| FR-004 | GitHub Actions CI/CD pipeline | Medium |
| FR-005 | Environment configuration (development, staging, production) | Medium |

### Non-Functional Requirements
- Performance: Backend should start in < 5 seconds
- Security: Database credentials stored securely (not in code)
- Compatibility: Works on Linux, Windows, and macOS
- Scalability: Infrastructure should support horizontal scaling

---

## 🏗️ Technical Design

### Components Involved
- **Backend**: ASP.NET Core Web API project
- **Database**: PostgreSQL 15+
- **Infrastructure**: Docker, Docker Compose
- **CI/CD**: GitHub Actions

### Architecture Diagram
```
┌─────────────────────────────────────────────────────────┐
│                        Infrastructure                       │
├─────────────────────────────────────────────────────────┤
│  ┌─────────────┐    ┌─────────────┐    ┌─────────────┐  │
│  │   Backend    │    │  Database   │    │    Frontend  │  │
│  │  (.NET 9.0)  │◄──►│ PostgreSQL  │    │   (React)    │  │
│  └─────────────┘    └─────────────┘    └─────────────┘  │
│       ▲                   ▲                    ▲        │
│       │                   │                    │        │
│  ┌────┴─────┐       ┌─────┴─────┐        ┌─────┴─────┐  │
│  │  Docker  │       │  Docker   │        │   Docker  │  │
│  │ Container│       │ Container │        │ Container │  │
│  └──────────┘       └───────────┘        └───────────┘  │
└─────────────────────────────────────────────────────────┘
```

### Data Flow
1. Developer runs `docker-compose up`
2. PostgreSQL container starts with initialized database
3. Backend container starts and connects to database
4. Frontend container starts and connects to backend API
5. Application is accessible at `http://localhost:3000`

---

## 🚀 Implementation Plan

### Phase 1: Backend Project Setup (2-4 hours)
- [ ] Create GermanApp .NET 9.0 Web API project
- [ ] Configure appsettings.json with multiple environments
- [ ] Set up Health Checks endpoint
- [ ] Configure CORS for frontend
- [ ] Set up OpenAPI/Swagger documentation
- [ ] Configure logging (Serilog or built-in)
- [ ] Create base response models and error handling middleware

### Phase 2: Database Setup (1-2 hours)
- [ ] Design and create initial database schema
- [ ] Configure Entity Framework Core with PostgreSQL
- [ ] Set up database migrations
- [ ] Create seed data scripts
- [ ] Configure connection strings for different environments

### Phase 3: Docker Configuration (2-4 hours)
- [ ] Create Dockerfile for backend
- [ ] Create Dockerfile for frontend
- [ ] Create docker-compose.yml with all services
- [ ] Configure Docker volumes for persistent data
- [ ] Set up environment variables in Docker
- [ ] Test Docker build and run

### Phase 4: CI/CD Pipeline (2-4 hours)
- [ ] Create GitHub Actions workflow for backend
- [ ] Configure build, test, and deploy steps
- [ ] Set up environment secrets
- [ ] Configure branch protection rules
- [ ] Test CI/CD pipeline

### Milestones
| Milestone | Date | Status |
|-----------|------|--------|
| Backend Project Created | - | ⏳ |
| Database Configured | - | ⏳ |
| Docker Setup Complete | - | ⏳ |
| CI/CD Pipeline Working | - | ⏳ |

---

## ✅ Tasks

### Backend
- [ ] Initialize .NET 9.0 Web API project
- [ ] Configure Program.cs with proper middleware
- [ ] Set up appsettings.Development.json, appsettings.Staging.json, appsettings.Production.json
- [ ] Create HealthChecks endpoint
- [ ] Configure Swagger/OpenAPI
- [ ] Set up CORS policy
- [ ] Configure logging
- [ ] Create error handling middleware
- [ ] Create base response wrappers

### Database
- [ ] Install PostgreSQL locally for development
- [ ] Create initial database schema
- [ ] Configure EF Core DbContext
- [ ] Create first migration
- [ ] Apply migration to database
- [ ] Create seed data for initial testing

### Docker
- [ ] Create backend Dockerfile
- [ ] Create frontend Dockerfile
- [ ] Create docker-compose.yml
- [ ] Configure Docker volumes
- [ ] Set up Docker .env file
- [ ] Test Docker containers

### CI/CD
- [ ] Create .github/workflows/ directory
- [ ] Create backend CI workflow
- [ ] Create frontend CI workflow
- [ ] Configure deployment workflow
- [ ] Set up GitHub secrets
- [ ] Test workflows

---

## 🔗 Dependencies

### Feature Dependencies
- None - This is the foundational feature

### Technical Dependencies
- .NET 9.0 SDK
- PostgreSQL 15+
- Docker & Docker Compose
- GitHub account with repository access

### Blockers
- [ ] None identified

---

## ✅ Definition of Done

### General Criteria (All Features)
- [ ] All acceptance criteria met and verified
- [ ] All tasks in this document completed
- [ ] Code follows Clean Architecture principles
- [ ] Code reviewed and approved by at least 1 team member
- [ ] All tests passing (unit, integration)
- [ ] Documentation updated (README, AGENTS.md if applicable)
- [ ] Feature works in development environment
- [ ] Feature deployed to staging environment
- [ ] Performance meets defined targets
- [ ] Security review completed
- [ ] No critical bugs or blockers

### Infrastructure-Specific Criteria
- [ ] .NET 9.0 backend project builds successfully
- [ ] PostgreSQL database is accessible and configured
- [ ] Docker containers build and run without errors
- [ ] CI/CD pipeline runs successfully on push
- [ ] Development environment is reproducible by new team members
- [ ] Health checks pass for all services
- [ ] Database migrations can be applied cleanly

---

## 🧪 Testing Strategy

### Testing Approach

| Test Type | Coverage | Tools | Responsibility |
|-----------|----------|-------|----------------|
| Unit Tests | 80%+ code coverage | MsTest, Moq | Backend Dev |
| Integration Tests | All service interactions | MsTest, TestContainers | Backend Dev |
| API Tests | All endpoints | MsTest, HttpClient | Backend Dev |
| Frontend Unit Tests | Component logic | Vitest | Frontend Dev |
| Frontend Integration | Service integration | Vitest | Frontend Dev |
| E2E Tests | Critical user journeys | Playwright | QA/Dev |
| Manual Testing | Exploratory, edge cases | BrowserStack | QA |

### Infrastructure-Specific Tests
- [ ] Verify .NET 9.0 project structure
- [ ] Test database connection and queries
- [ ] Test Docker build process
- [ ] Test Docker Compose startup
- [ ] Test CI/CD pipeline execution
- [ ] Test health check endpoints
- [ ] Test database migration process
- [ ] Test backup and restore procedures

---

## 📝 Notes & Decisions

### Decisions Made
| Date | Decision | Rationale |
|------|----------|-----------|
| May 31, 2025 | Use PostgreSQL over SQLite | Better for production, supports more features, widely used |
| May 31, 2025 | Use Docker Compose | Simplified local development setup |
| May 31, 2025 | GitHub Actions for CI/CD | Native GitHub integration, free for public repos |

### Technical Notes
- Connection strings should use environment variables, not hardcoded values
- Docker volumes should be used for PostgreSQL data to persist between restarts
- Health checks should verify database connectivity

### Gotchas
- ⚠️ Docker on Windows may have volume mounting issues - use WSL2
- ⚠️ PostgreSQL container needs explicit volume for data persistence
- ⚠️ EF Core tools need to be installed for migrations

---

## 📊 Progress History

| Date | Status Change | Notes |
|------|---------------|-------|
| May 31, 2025 | Created | Initial plan based on application-plan.md |

---

## 📎 Related Files & Links

- Architecture: [Backend Structure](../architecture/backend-structure.md)
- Database Schema: [Initial Database Schema](../database/initial-database-schema.sql)
- Development: [How to Run Vibe](../development/how-to-run-vibe.md)
- Application Plan: [Application Plan](../architecture/application-plan.md)

---

*Feature created from application-plan.md*