# Shared Utilities & Common Components - Business Requirements

**Document Version**: 1.0
**Date**: January 2025
**Status**: Business Requirements Specification
**Module**: Shared Utilities & Common Components (`pkg/shared/`, `internal/config/`, `internal/validation/`)

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## 1. Purpose & Scope

### 1.1 Business Purpose
The Shared Utilities & Common Components layer provides foundational capabilities that support all other Kubernaut components, ensuring consistency, reliability, and maintainability through centralized error handling, logging, configuration management, validation, and common data structures.

### 1.2 Scope
- **Error Management**: Enhanced error handling and classification systems
- **HTTP Utilities**: Reusable HTTP client and server functionality
- **Logging Framework**: Structured logging and observability support
- **Mathematical Utilities**: Statistical functions and algorithms
- **Common Types**: Shared data structures and type definitions
- **Context Management**: Request context handling and enrichment
- **Configuration Services**: Application configuration and environment management
- **Validation Framework**: Input validation and business rule enforcement

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## 2. Error Management

### 2.1 Business Capabilities

#### 2.1.1 Enhanced Error Handling
- **BR-ERR-001**: MUST provide rich error types with detailed context information
- **BR-ERR-002**: MUST implement error classification by severity and category
- **BR-ERR-003**: MUST support error chaining and cause tracking
- **BR-ERR-004**: MUST provide error serialization for logging and transmission
- **BR-ERR-005**: MUST implement error code standardization across components

#### 2.1.2 Error Context & Traceability
- **BR-ERR-006**: MUST capture error context including stack traces and metadata
- **BR-ERR-007**: MUST provide error correlation IDs for distributed tracing
- **BR-ERR-008**: MUST implement error aggregation and deduplication
- **BR-ERR-009**: MUST support error annotation and enrichment
- **BR-ERR-010**: MUST maintain error history and pattern tracking

#### 2.1.3 Error Recovery & Handling
- **BR-ERR-011**: MUST provide error recovery strategies and recommendations
- **BR-ERR-012**: MUST implement retry mechanisms with configurable policies
- **BR-ERR-013**: MUST support circuit breaker patterns for error isolation
- **BR-ERR-014**: MUST provide graceful degradation capabilities
- **BR-ERR-015**: MUST implement error notification and escalation

#### 2.1.4 Error Analytics
- **BR-ERR-016**: MUST track error patterns and frequency analysis
- **BR-ERR-017**: MUST provide error impact assessment and business metrics
- **BR-ERR-018**: MUST implement predictive error detection
- **BR-ERR-019**: MUST support error trend analysis and forecasting
- **BR-ERR-020**: MUST provide error resolution effectiveness tracking

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## 3. HTTP Utilities

### 3.1 Business Capabilities

#### 3.1.1 HTTP Client Management
- **BR-HTTP-001**: MUST provide reusable HTTP client implementations with connection pooling
- **BR-HTTP-002**: MUST support configurable timeouts and retry policies
- **BR-HTTP-003**: MUST implement request/response middleware for common operations
- **BR-HTTP-004**: MUST provide authentication and authorization support
- **BR-HTTP-005**: MUST support multiple content types and serialization formats

#### 3.1.2 Request/Response Processing
- **BR-HTTP-006**: MUST implement request validation and sanitization
- **BR-HTTP-007**: MUST provide response caching and optimization
- **BR-HTTP-008**: MUST support request/response compression
- **BR-HTTP-009**: MUST implement rate limiting and throttling
- **BR-HTTP-010**: MUST provide request correlation and tracing

#### 3.1.3 Security & Reliability
- **BR-HTTP-011**: MUST implement HTTPS/TLS support with certificate validation
- **BR-HTTP-012**: MUST provide secure header handling and validation
- **BR-HTTP-013**: MUST implement request size limits and protection
- **BR-HTTP-014**: MUST support secure cookie and session management
- **BR-HTTP-015**: MUST provide CORS and security policy enforcement

#### 3.1.4 Monitoring & Observability
- **BR-HTTP-016**: MUST track HTTP request/response metrics and performance
- **BR-HTTP-017**: MUST provide request logging with configurable detail levels
- **BR-HTTP-018**: MUST implement health check endpoints and monitoring
- **BR-HTTP-019**: MUST support distributed tracing for HTTP operations
- **BR-HTTP-020**: MUST provide HTTP error tracking and analysis

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## 4. Logging Framework

### 4.1 Business Capabilities

#### 4.1.1 Structured Logging
- **BR-LOG-001**: MUST provide structured logging with JSON format support
- **BR-LOG-002**: MUST implement configurable log levels and filtering
- **BR-LOG-003**: MUST support contextual logging with correlation IDs
- **BR-LOG-004**: MUST provide field-based logging with consistent schema
- **BR-LOG-005**: MUST implement log sampling and rate limiting

#### 4.1.2 Log Management
- **BR-LOG-006**: MUST support multiple output destinations (stdout, files, remote)
- **BR-LOG-007**: MUST implement log rotation and retention policies
- **BR-LOG-008**: MUST provide log compression and archival
- **BR-LOG-009**: MUST support log forwarding and centralized collection
- **BR-LOG-010**: MUST implement log buffering and batch processing

#### 4.1.3 Security & Compliance
- **BR-LOG-011**: MUST sanitize logs to prevent credential and PII exposure
- **BR-LOG-012**: MUST implement log encryption for sensitive information
- **BR-LOG-013**: MUST provide audit logging for compliance requirements
- **BR-LOG-014**: MUST support log integrity verification
- **BR-LOG-015**: MUST implement secure log transmission and storage

#### 4.1.4 Observability Integration
- **BR-LOG-016**: MUST integrate with distributed tracing systems
- **BR-LOG-017**: MUST support metrics extraction from log data
- **BR-LOG-018**: MUST provide log correlation with business events
- **BR-LOG-019**: MUST implement intelligent log analysis and alerting
- **BR-LOG-020**: MUST support log-based debugging and troubleshooting

---

## 5. Mathematical Utilities

### 5.1 Business Capabilities

#### 5.1.1 Statistical Functions
- **BR-MATH-001**: MUST provide descriptive statistics (mean, median, variance, etc.)
- **BR-MATH-002**: MUST implement probability distributions and sampling
- **BR-MATH-003**: MUST support hypothesis testing and confidence intervals
- **BR-MATH-004**: MUST provide correlation and regression analysis
- **BR-MATH-005**: MUST implement time series analysis functions

#### 5.1.2 Optimization Algorithms
- **BR-MATH-006**: MUST provide optimization algorithms for parameter tuning
- **BR-MATH-007**: MUST implement search algorithms for pattern matching
- **BR-MATH-008**: MUST support numerical methods for equation solving
- **BR-MATH-009**: MUST provide graph algorithms for dependency analysis
- **BR-MATH-010**: MUST implement clustering and classification algorithms

#### 5.1.3 Data Processing
- **BR-MATH-011**: MUST provide data normalization and scaling functions
- **BR-MATH-012**: MUST implement outlier detection and handling
- **BR-MATH-013**: MUST support data transformation and feature engineering
- **BR-MATH-014**: MUST provide distance metrics and similarity measures
- **BR-MATH-015**: MUST implement matrix operations and linear algebra

#### 5.1.4 Performance & Precision
- **BR-MATH-016**: MUST optimize mathematical operations for performance
- **BR-MATH-017**: MUST provide configurable precision and accuracy
- **BR-MATH-018**: MUST handle numerical stability and edge cases
- **BR-MATH-019**: MUST support parallel processing for large datasets
- **BR-MATH-020**: MUST implement memory-efficient algorithms

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## 6. Common Types & Data Structures

### 6.1 Business Capabilities

#### 6.1.1 Core Data Structures
- **BR-TYPE-001**: MUST provide standardized alert and event data structures
- **BR-TYPE-002**: MUST implement common configuration and parameter types
- **BR-TYPE-003**: MUST provide resource and entity definitions
- **BR-TYPE-004**: MUST implement status and state enumerations
- **BR-TYPE-005**: MUST provide timestamp and duration handling

#### 6.1.2 Serialization & Validation
- **BR-TYPE-006**: MUST support JSON, YAML, and XML serialization
- **BR-TYPE-007**: MUST implement data validation and schema enforcement
- **BR-TYPE-008**: MUST provide type conversion and compatibility
- **BR-TYPE-009**: MUST support versioning and backward compatibility
- **BR-TYPE-010**: MUST implement data integrity checks and validation

#### 6.1.3 Collections & Utilities
- **BR-TYPE-011**: MUST provide generic collection types and operations
- **BR-TYPE-012**: MUST implement thread-safe data structures
- **BR-TYPE-013**: MUST support immutable data types where appropriate
- **BR-TYPE-014**: MUST provide efficient lookup and indexing structures
- **BR-TYPE-015**: MUST implement data comparison and equality functions

#### 6.1.4 Domain-Specific Types
- **BR-TYPE-016**: MUST provide Kubernetes-specific data structures
- **BR-TYPE-017**: MUST implement AI/ML specific data types
- **BR-TYPE-018**: MUST provide workflow and orchestration types
- **BR-TYPE-019**: MUST implement monitoring and metrics types
- **BR-TYPE-020**: MUST provide security and authentication types

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## 7. Context Management

### 7.1 Business Capabilities

#### 7.1.1 Request Context Handling
- **BR-CTX-001**: MUST provide request context propagation across components
- **BR-CTX-002**: MUST implement context timeout and cancellation
- **BR-CTX-003**: MUST support context enrichment with metadata
- **BR-CTX-004**: MUST provide context serialization for distributed operations
- **BR-CTX-005**: MUST implement context validation and sanitization

#### 7.1.2 Context Enrichment
- **BR-CTX-006**: MUST add correlation IDs for request tracing
- **BR-CTX-007**: MUST inject user and authentication context
- **BR-CTX-008**: MUST provide environmental context (cluster, namespace, etc.)
- **BR-CTX-009**: MUST add timing and performance context
- **BR-CTX-010**: MUST implement business context and metadata

#### 7.1.3 Context Utilities
- **BR-CTX-011**: MUST provide context extraction and manipulation utilities
- **BR-CTX-012**: MUST implement context cloning and inheritance
- **BR-CTX-013**: MUST support context merging and composition
- **BR-CTX-014**: MUST provide context debugging and inspection
- **BR-CTX-015**: MUST implement context cleanup and resource management

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## 8. Configuration Management

### 8.1 Business Capabilities

#### 8.1.1 Configuration Loading
- **BR-CFG-001**: MUST support multiple configuration sources (files, environment, CLI)
- **BR-CFG-002**: MUST implement configuration precedence and merging
- **BR-CFG-003**: MUST provide configuration validation and error reporting
- **BR-CFG-004**: MUST support encrypted configuration values
- **BR-CFG-005**: MUST implement configuration hot-reloading where safe

#### 8.1.2 Environment Management
- **BR-CFG-006**: MUST support environment-specific configuration profiles
- **BR-CFG-007**: MUST provide configuration template and substitution
- **BR-CFG-008**: MUST implement configuration inheritance and overrides
- **BR-CFG-009**: MUST support dynamic configuration discovery
- **BR-CFG-010**: MUST provide configuration backup and versioning

#### 8.1.3 Configuration Security
- **BR-CFG-011**: MUST implement secure credential and secret management
- **BR-CFG-012**: MUST provide configuration access control and permissions
- **BR-CFG-013**: MUST support configuration audit logging
- **BR-CFG-014**: MUST implement configuration change notifications
- **BR-CFG-015**: MUST provide configuration integrity verification

#### 8.1.4 Configuration Monitoring
- **BR-CFG-016**: MUST track configuration usage and effectiveness
- **BR-CFG-017**: MUST monitor configuration changes and impacts
- **BR-CFG-018**: MUST provide configuration compliance checking
- **BR-CFG-019**: MUST implement configuration performance monitoring
- **BR-CFG-020**: MUST support configuration optimization recommendations

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## 9. Validation Framework

### 9.1 Business Capabilities

#### 9.1.1 Input Validation
- **BR-VAL-001**: MUST provide comprehensive input validation for all data types
- **BR-VAL-002**: MUST implement field-level and cross-field validation
- **BR-VAL-003**: MUST support custom validation rules and logic
- **BR-VAL-004**: MUST provide validation error aggregation and reporting
- **BR-VAL-005**: MUST implement internationalized validation messages

#### 9.1.2 Business Rule Validation
- **BR-VAL-006**: MUST implement business rule validation engine
- **BR-VAL-007**: MUST support configurable validation policies
- **BR-VAL-008**: MUST provide rule composition and dependency validation
- **BR-VAL-009**: MUST implement validation workflow and approval processes
- **BR-VAL-010**: MUST support validation rule versioning and management

#### 9.1.3 Data Integrity
- **BR-VAL-011**: MUST validate data consistency and integrity
- **BR-VAL-012**: MUST implement referential integrity checks
- **BR-VAL-013**: MUST provide data format and schema validation
- **BR-VAL-014**: MUST support data quality assessment and scoring
- **BR-VAL-015**: MUST implement data sanitization and cleansing

#### 9.1.4 Security Validation
- **BR-VAL-016**: MUST implement security-focused input validation
- **BR-VAL-017**: MUST provide injection attack prevention
- **BR-VAL-018**: MUST validate authentication and authorization data
- **BR-VAL-019**: MUST implement rate limiting validation
- **BR-VAL-020**: MUST provide security policy compliance validation

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## 10. Performance Requirements

### 10.1 Utility Performance
- **BR-PERF-001**: Error handling MUST add <1ms overhead to operations
- **BR-PERF-002**: HTTP utilities MUST support 10,000 concurrent connections
- **BR-PERF-003**: Logging operations MUST complete within 1ms
- **BR-PERF-004**: Mathematical operations MUST optimize for large datasets
- **BR-PERF-005**: Context operations MUST add <0.1ms overhead

### 10.2 Configuration Performance
- **BR-PERF-006**: Configuration loading MUST complete within 5 seconds
- **BR-PERF-007**: Configuration validation MUST complete within 1 second
- **BR-PERF-008**: Hot-reload operations MUST complete within 10 seconds
- **BR-PERF-009**: Configuration queries MUST respond within 1ms
- **BR-PERF-010**: MUST support 1000+ configuration parameters efficiently

### 10.3 Validation Performance
- **BR-PERF-011**: Input validation MUST complete within 10ms for standard inputs
- **BR-PERF-012**: Business rule validation MUST complete within 100ms
- **BR-PERF-013**: MUST support 1000+ validation rules efficiently
- **BR-PERF-014**: Batch validation MUST process 10,000 items per minute
- **BR-PERF-015**: MUST optimize validation for high-throughput scenarios

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## 11. Reliability & Quality Requirements

### 11.1 Code Quality
- **BR-QUAL-001**: MUST maintain >95% test coverage for all shared utilities
- **BR-QUAL-002**: MUST implement comprehensive error handling and edge cases
- **BR-QUAL-003**: MUST provide extensive documentation and examples
- **BR-QUAL-004**: MUST follow consistent coding standards and patterns
- **BR-QUAL-005**: MUST implement performance benchmarks and optimization

### 11.2 Stability & Compatibility
- **BR-QUAL-006**: MUST maintain backward compatibility for all public APIs
- **BR-QUAL-007**: MUST provide stable interfaces with versioning support
- **BR-QUAL-008**: MUST implement graceful handling of invalid inputs
- **BR-QUAL-009**: MUST support multiple Go versions and platforms
- **BR-QUAL-010**: MUST provide migration guides for breaking changes

### 11.3 Security & Safety
- **BR-QUAL-011**: MUST implement secure defaults for all utilities
- **BR-QUAL-012**: MUST validate all inputs to prevent vulnerabilities
- **BR-QUAL-013**: MUST provide secure random generation and cryptographic functions
- **BR-QUAL-014**: MUST implement memory safety and resource cleanup
- **BR-QUAL-015**: MUST support security scanning and vulnerability assessment

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## 12. Integration & Compatibility

### 12.1 Internal Integration
- **BR-INT-001**: MUST provide consistent interfaces used by all Kubernaut components
- **BR-INT-002**: MUST support dependency injection and inversion of control
- **BR-INT-003**: MUST implement factory patterns for component creation
- **BR-INT-004**: MUST provide plugin and extension mechanisms
- **BR-INT-005**: MUST support modular architecture and loose coupling

### 12.2 External Integration
- **BR-INT-006**: MUST integrate with standard Go ecosystem libraries
- **BR-INT-007**: MUST support OpenTelemetry for observability
- **BR-INT-008**: MUST integrate with popular logging frameworks
- **BR-INT-009**: MUST support standard configuration formats (JSON, YAML, TOML)
- **BR-INT-010**: MUST provide compatibility with container and Kubernetes environments

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## 13. Documentation & Usability

### 13.1 Documentation Requirements
- **BR-DOC-001**: MUST provide comprehensive API documentation
- **BR-DOC-002**: MUST include usage examples and best practices
- **BR-DOC-003**: MUST provide troubleshooting guides and FAQs
- **BR-DOC-004**: MUST maintain architectural decision records (ADRs)
- **BR-DOC-005**: MUST provide performance tuning and optimization guides

### 13.2 Developer Experience
- **BR-DOC-006**: MUST provide intuitive and consistent APIs
- **BR-DOC-007**: MUST include comprehensive unit and integration tests
- **BR-DOC-008**: MUST provide debugging and diagnostic utilities
- **BR-DOC-009**: MUST support IDE integration and auto-completion
- **BR-DOC-010**: MUST provide migration tools and compatibility helpers

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## 14. Monitoring & Observability

### 14.1 Utility Monitoring
- **BR-MON-001**: MUST provide metrics for all shared utility usage
- **BR-MON-002**: MUST track error rates and performance metrics
- **BR-MON-003**: MUST monitor resource utilization and optimization opportunities
- **BR-MON-004**: MUST provide health checks for critical utilities
- **BR-MON-005**: MUST implement distributed tracing for utility operations

### 14.2 Business Metrics
- **BR-MON-006**: MUST track utility adoption and usage patterns
- **BR-MON-007**: MUST monitor utility effectiveness and business impact
- **BR-MON-008**: MUST provide cost analysis for utility operations
- **BR-MON-009**: MUST track developer productivity improvements
- **BR-MON-010**: MUST measure code quality and maintainability metrics

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## 15. Success Criteria

### 15.1 Technical Success
- Shared utilities provide consistent, reliable foundation for all components
- Error handling reduces debugging time by 60% through enhanced context
- HTTP utilities support high-performance, secure communication
- Logging framework provides comprehensive observability with minimal overhead
- Mathematical utilities enable accurate and efficient analytical operations

### 15.2 Developer Success
- Utilities reduce development time by 40% through reusable components
- Configuration management simplifies deployment across environments
- Validation framework prevents 95% of data-related issues
- Documentation enables rapid onboarding and effective usage
- APIs provide intuitive, consistent interface across all utilities

### 15.3 Operational Success
- Shared components contribute to overall system reliability >99.9%
- Performance overhead of utilities remains <1% of total system resources
- Error handling and logging enable rapid issue diagnosis and resolution
- Configuration management supports zero-downtime deployments
- Validation framework prevents security vulnerabilities and data corruption

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*This document serves as the definitive specification for business requirements of Kubernaut's Shared Utilities & Common Components. All implementation and testing should align with these requirements to ensure a solid, consistent, and maintainable foundation for the entire Kubernaut system.*
