Git Provider Sync - Software Architecture Documentation

1. Introduction and Goals

1.1 Requirements Overview

Primary capabilities:

Mirror repositories between different Git providers
Batch clone repositories to local storage
Archive repositories into compressed files
Support multiple source and target configurations

1.2 Quality Goals

1. Security

Limited token access
Security scanning integration
OpenSSF best practices compliance

2. Reliability

Error handling for sync operations
Validation of sync states
Support for retries

3. Maintainability

Modular provider system
Comprehensive testing
Quality assurance automation

1.3 Stakeholders

Developers using multiple git providers
Organizations needing repository mirroring
DevOps teams managing git infrastructure
Open source contributors

2. Architecture Constraints

2.1 Technical Constraints

Go version 1.23+
Git 2.43+
Provider-specific API limitations
Rate limiting considerations

2.2 Organizational Constraints

EUPL 1.2 License compliance
REUSE specification compliance
Conventional Commits standard
Developer Certificate of Origin (DCO) requirement

3. System Scope and Context

3.1 Business Context

The system operates in an environment where there is a need to maintain repository synchronization across Git providers. This could be for various reasons:

1. Backup and Redundancy

Maintaining copies of repositories across different providers
Creating local backups for disaster recovery
Archiving repositories for compliance

2. Migration Support

Facilitating provider transitions
Supporting multi-provider strategies
Enabling gradual migrations

3. Cross-Platform Development

Supporting development across different Git platforms
Maintaining mirrors for different user groups
Enabling platform-specific features while maintaining synchronization

The context diagram above illustrates the key interactions between the system and its environment.

3.2 Technical Context

The system has support for interacting with various external systems through different interfaces:

1. Git Provider APIs

GitHub API:
  - Example Base URL: api.github.com
  - Version: v3
  - Auth: OAuth tokens

GitLab API:
  - Example Base URL: gitlab.com/api
  - Version: v4
  - Auth: Personal access tokens

Gitea API:
  - Example Base URL: <instance>/api
  - Version: v1
  - Auth: Access tokens

2. Authentication Methods

HTTP:
  - Token-based authentication
  - Rate limit considerations
  - API-specific headers

SSH:
  - Key-based authentication
  - SSH Command support
  - Custom SSH configurations

4. Solution Strategy

1. Provider Abstraction

Modular
Common interface for different git providers
Extensible for new providers

2. Configuration Management

Hierarchical configuration system
Multiple configuration sources
Environment variable support

3. Sync Process

State-based synchronization
Validation steps
Error handling and retry mechanisms

4. Security

Token-based authentication
Limited scope access

5. Building Block View

5.1 Level 1: System Overview

Main components:

Git Provider Sync
├── Provider System
│   ├── GitHub Provider
│   ├── GitLab Provider
│   └── Gitea Provider
├── Target System
│   ├── Git Providers
│   ├── Archive Target
│   └── Directory Target
├── Configuration Management
└── Sync Engine

5.2 Level 2: Component Details

Provider System

Handles provider-specific API interactions
Manages authentication
Implements provider-specific features

Target System

Manages repository destinations
Handles different target types
Implements target-specific operations

Configuration Management

Processes multiple config sources
Validates configurations
Manages environment variables

Sync Engine

Coordinates sync operations
Handles state management
Implements retry logic

6. Runtime View

6.1 High-Level Process Overview

The sequence diagram above illustrates the core synchronization process at its highest level:

1. Periodic Sync Loop

The process runs either on schedule or manual trigger
Each iteration handles the complete sync cycle

2. Core Interactions

Fetch: Get current state and changes from source provider
Process: Handle the returned changes internally
Mirror: Push updates to target provider
Verify: Confirm successful synchronization

3. Communication Pattern

Synchronous request-response pattern
Provider-agnostic interface

6.2 Detailed Sync Process Flow

1. Authentication & Setup

Initialize API connections
Validate credentials

2. Repository Discovery

List repositories
Apply filters

3. State Comparison

Fetch metadata
Compare states

4. Sync Process

Clone/fetch repositories
Process changes
Push updates

5. Validation

Update status

6.3 Implementation Details

To-Do

7. Deployment View

7.1 Infrastructure

Supports deployment as:

CLI application
Container in CI/CD systems
Scheduled job (cron)
Manual trigger

7.2 CI/CD Integration

Supported platforms:

GitLab CI
GitHub Actions
Tekton
Kubernetes CronJobs

8. Cross-cutting Concepts

8.1 Development Concepts

Test-driven development
Comprehensive quality checks
Security-first approach
Open source best practices

8.2 Security Concepts

Limited token access
Signed commits
Security scanning
Vulnerability checking

9. Architecture Decisions

1. Use of Go for implementation

Strong standard library
Built-in concurrency support
Cross-platform compatibility

2. Modular provider system

Extensibility
Provider-specific implementations
Common interfaces

3. Configuration hierarchy

Multiple configuration sources
Clear precedence rules
Environment variable support

10. Quality Requirements

10.1 Quality Scenarios