# KMS API Service - Production Roadmap

This document outlines the complete roadmap for making the API Key Management Service fully production-ready. Use the checkboxes to track progress and refer to the implementation notes at the bottom.

## 🏗️ Core Infrastructure (COMPLETED)

### Repository Layer
- [x] Complete token repository implementation (CRUD operations)
- [x] Complete permission repository implementation (core methods)
- [x] Implement granted permission repository (authorization logic)
- [x] Add database transaction support
- [x] Implement proper error handling in repositories

### Security & Cryptography
- [x] Implement secure token generation using crypto/rand
- [x] Add bcrypt-based token hashing for storage
- [x] Implement HMAC token signing and verification
- [x] Create token format validation utilities
- [x] Add cryptographic key management

### Service Layer
- [x] Update token service with secure generation
- [x] Implement permission validation in token creation
- [x] Add application validation before token operations
- [x] Implement proper error propagation
- [x] Add comprehensive logging throughout services

### Middleware & Validation
- [x] Create comprehensive input validation middleware
- [x] Implement struct-based validation with detailed errors
- [x] Add UUID parameter validation
- [x] Create permission scope format validation
- [x] Implement request sanitization

### Error Handling
- [x] Create structured error framework with typed codes
- [x] Implement HTTP status code mapping
- [x] Add error context and chaining support
- [x] Create consistent JSON error responses
- [x] Add retry logic indicators

### Monitoring & Metrics
- [x] Implement comprehensive metrics collection
- [x] Add Prometheus-compatible metrics export
- [x] Create HTTP request monitoring middleware
- [x] Add business metrics tracking
- [x] Implement system health metrics

## 🔐 Authentication & Authorization (HIGH PRIORITY)

### JWT Implementation
- [x] Complete JWT token generation and validation
- [x] Implement token expiration and renewal logic
- [x] Add JWT claims management
- [x] Create token blacklisting mechanism
- [x] Implement refresh token rotation
- [x] Add comprehensive JWT unit tests with benchmarks
- [x] Implement cache-based token revocation system

### SSO Integration
- [x] Implement OAuth2/OIDC provider integration
- [x] Add OAuth2 authentication handlers with PKCE support
- [x] Create OAuth2 discovery document fetching
- [x] Implement authorization code exchange and token refresh
- [x] Add user info retrieval from OAuth2 providers
- [x] Create comprehensive OAuth2 unit tests with benchmarks
- [ ] Add SAML authentication support
- [ ] Create user session management
- [x] Implement role-based access control (RBAC)
- [ ] Add multi-tenant authentication support

### Permission System Enhancement
- [x] Implement hierarchical permission inheritance
- [x] Add dynamic permission evaluation
- [x] Create permission caching mechanism
- [x] Add bulk permission operations
- [x] Implement default permission hierarchy (admin, read, write, app.*, token.*, etc.)
- [x] Create role-based permission system with inheritance
- [x] Add comprehensive permission unit tests with benchmarks
- [ ] Implement permission audit logging

## 🚀 Performance & Scalability (MEDIUM PRIORITY)

### Caching Layer
- [x] Implement basic caching layer with memory provider
- [x] Add JSON serialization/deserialization support
- [x] Create cache manager with TTL support
- [x] Add cache key management and prefixes
- [x] Implement Redis integration for caching
- [x] Add token blacklist caching for revocation
- [ ] Add permission result caching
- [ ] Create application metadata caching
- [ ] Implement token validation result caching
- [ ] Add cache invalidation strategies

### Database Optimization
- [ ] Implement database connection pool tuning
- [ ] Add query performance monitoring
- [ ] Create database migration rollback procedures
- [ ] Implement read replica support
- [ ] Add database backup and recovery procedures

### Load Balancing & Clustering
- [ ] Implement horizontal scaling support
- [ ] Add load balancer health checks
- [ ] Create session affinity handling
- [ ] Implement distributed rate limiting
- [ ] Add circuit breaker patterns

## 🔒 Security Hardening (HIGH PRIORITY)

### Advanced Security Features
- [ ] Implement API key rotation mechanisms
- [x] Add brute force protection
- [x] Create account lockout mechanisms
- [x] Implement IP whitelisting/blacklisting
- [x] Add request signing validation
- [x] Implement rate limiting middleware
- [x] Add security headers middleware
- [x] Create authentication failure tracking

### Audit & Compliance
- [ ] Implement comprehensive audit logging
- [ ] Add compliance reporting features
- [ ] Create data retention policies
- [ ] Implement GDPR compliance features
- [ ] Add security event alerting

### Secrets Management
- [ ] Integrate with HashiCorp Vault or similar
- [ ] Implement automatic key rotation
- [ ] Add encrypted configuration storage
- [ ] Create secure backup procedures
- [ ] Implement key escrow mechanisms

## 🧪 Testing & Quality Assurance (MEDIUM PRIORITY)

### Unit Testing
- [x] Add comprehensive JWT authentication unit tests
- [x] Create caching layer unit tests with benchmarks
- [x] Implement authentication service unit tests
- [x] Add comprehensive permission system unit tests
- [ ] Add comprehensive unit tests for repositories
- [ ] Create service layer unit tests
- [ ] Implement middleware unit tests
- [ ] Add crypto utility unit tests
- [ ] Create error handling unit tests

### Integration Testing
- [ ] Expand integration test coverage
- [ ] Add database integration tests
- [ ] Create API endpoint integration tests
- [ ] Implement authentication flow tests
- [ ] Add permission validation tests

### Performance Testing
- [ ] Implement load testing scenarios
- [ ] Add stress testing for concurrent operations
- [ ] Create database performance benchmarks
- [ ] Implement memory leak detection
- [ ] Add latency and throughput testing

### Security Testing
- [ ] Implement penetration testing scenarios
- [ ] Add vulnerability scanning automation
- [ ] Create security regression tests
- [ ] Implement fuzzing tests
- [ ] Add compliance validation tests

## 📦 Deployment & Operations (MEDIUM PRIORITY)

### Containerization & Orchestration
- [ ] Create optimized Docker images
- [ ] Implement Kubernetes manifests
- [ ] Add Helm charts for deployment
- [ ] Create deployment automation scripts
- [ ] Implement blue-green deployment strategy

### Infrastructure as Code
- [ ] Create Terraform configurations
- [ ] Implement AWS/GCP/Azure resource definitions
- [ ] Add infrastructure testing
- [ ] Create disaster recovery procedures
- [ ] Implement infrastructure monitoring

### CI/CD Pipeline
- [ ] Implement automated testing pipeline
- [ ] Add security scanning in CI/CD
- [ ] Create automated deployment pipeline
- [ ] Implement rollback mechanisms
- [ ] Add deployment notifications

## 📊 Observability & Monitoring (LOW PRIORITY)

### Advanced Monitoring
- [ ] Implement distributed tracing
- [ ] Add application performance monitoring (APM)
- [ ] Create custom dashboards
- [ ] Implement alerting rules
- [ ] Add log aggregation and analysis

### Business Intelligence
- [ ] Create usage analytics
- [ ] Implement cost tracking
- [ ] Add capacity planning metrics
- [ ] Create business KPI dashboards
- [ ] Implement trend analysis

## 🔧 Maintenance & Operations (ONGOING)

### Documentation
- [ ] Create comprehensive API documentation
- [ ] Add deployment guides
- [ ] Create troubleshooting runbooks
- [ ] Implement architecture decision records (ADRs)
- [ ] Add security best practices guide

### Maintenance Procedures
- [ ] Create backup and restore procedures
- [ ] Implement log rotation and archival
- [ ] Add database maintenance scripts
- [ ] Create performance tuning guides
- [ ] Implement capacity planning procedures

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## 📝 Implementation Notes for Future Development

### Code Organization Principles
1. **Maintain Clean Architecture**: Keep clear separation between domain, service, and infrastructure layers
2. **Interface-First Design**: Always define interfaces before implementations for better testability
3. **Error Handling**: Use the established error framework (`internal/errors`) for consistent error handling
4. **Logging**: Use structured logging with zap throughout the application
5. **Configuration**: Add new config options to `internal/config/config.go` with proper validation

### Security Guidelines
1. **Input Validation**: Always validate inputs using the validation middleware (`internal/middleware/validation.go`)
2. **Token Security**: Use the crypto utilities (`internal/crypto/token.go`) for all token operations
3. **Permission Checks**: Always validate permissions using the repository layer before operations
4. **Audit Logging**: Log all security-relevant operations with user context
5. **Secrets**: Never hardcode secrets; use environment variables or secret management systems

### Database Guidelines
1. **Migrations**: Always create both up and down migrations for schema changes
2. **Transactions**: Use database transactions for multi-step operations
3. **Indexing**: Add appropriate indexes for query performance
4. **Connection Management**: Use the existing connection pool configuration
5. **Error Handling**: Wrap database errors with the application error framework

### Testing Guidelines
1. **Test Structure**: Follow the existing test structure in `test/` directory
2. **Mock Dependencies**: Use interfaces for easy mocking in tests
3. **Test Data**: Use the test helpers for consistent test data creation
4. **Integration Tests**: Test against real database instances when possible
5. **Coverage**: Aim for >80% test coverage for critical paths

### Performance Guidelines
1. **Metrics**: Use the metrics system (`internal/metrics`) to track performance
2. **Caching**: Implement caching at the service layer, not repository layer
3. **Database Queries**: Optimize queries and use appropriate indexes
4. **Memory Management**: Be mindful of memory allocations in hot paths
5. **Concurrency**: Use proper synchronization for shared resources

### Deployment Guidelines
1. **Environment Variables**: Use environment-based configuration for all deployments
2. **Health Checks**: Ensure health endpoints are properly configured
3. **Graceful Shutdown**: Implement proper shutdown procedures for all services
4. **Resource Limits**: Set appropriate CPU and memory limits
5. **Monitoring**: Ensure metrics and logging are properly configured

### Code Quality Standards
1. **Go Standards**: Follow standard Go conventions and best practices
2. **Documentation**: Document all public APIs and complex business logic
3. **Error Messages**: Provide clear, actionable error messages
4. **Code Reviews**: Require code reviews for all changes
5. **Static Analysis**: Use tools like golangci-lint for code quality

### Security Best Practices
1. **Principle of Least Privilege**: Grant minimum necessary permissions
2. **Defense in Depth**: Implement multiple layers of security
3. **Regular Updates**: Keep dependencies updated for security patches
4. **Secure Defaults**: Use secure configurations by default
5. **Security Testing**: Include security testing in the development process

### Operational Considerations
1. **Monitoring**: Implement comprehensive monitoring and alerting
2. **Backup Strategy**: Ensure regular backups and test restore procedures
3. **Disaster Recovery**: Have documented disaster recovery procedures
4. **Capacity Planning**: Monitor resource usage and plan for growth
5. **Documentation**: Keep operational documentation up to date

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## 🎯 Priority Matrix

### Immediate (Next Sprint)
- Complete JWT implementation
- Add comprehensive unit tests
- Implement caching layer basics

### Short Term (1-2 Months)
- SSO integration
- Security hardening features
- Performance optimization

### Medium Term (3-6 Months)
- Advanced monitoring and observability
- Deployment automation
- Compliance features

### Long Term (6+ Months)
- Advanced analytics
- Multi-region deployment
- Advanced security features

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*Last Updated: [Current Date]*
*Version: 1.0*