Design Choices and Patterns

This document explains the technical choices and design patterns implemented in the codebase.

CLI Framework: Cobra & Viper

We use Cobra for command structure and Viper for configuration management.

• Why?: This is the standard in the Go ecosystem (used by Kubernetes, Hugo, GitHub CLI). It provides a robust way to handle flags, config files, and environment variables seamlessly.
• Pattern: Commands are defined in the cmd/ package, keeping main.go minimal.

HTTP Client: Resty

We use Resty for HTTP communication.

• Why?: It simplifies common tasks like JSON marshaling/unmarshaling, setting headers, and handling retries. It reduces boilerplate code compared to the standard net/http library.

Parsing Strategy: Regex vs. Libraries

The agent parses dnf output using Regular Expressions.

• Why not use libdnf?: Using C bindings (cgo) for libdnf would complicate the build process and cross-compilation. Parsing the CLI output allows the agent to be a static Go binary that works across different RPM-based distributions without dependency hell.
• Trade-off: This makes the agent sensitive to changes in DNF's output format, but provides greater portability.

Error Handling

The application follows Go's explicit error handling pattern but adds context.

• Pattern: Errors are propagated up the stack and logged at the top level (usually in the Run function of the Cobra command).
• User Feedback: We distinguish between "system errors" (stack traces, debug logs) and "user errors" (configuration issues), presenting the latter with clear, colored messages.