separation-of-concerns-pattern-overview

To separate CLI concerns from business logic in Go, isolate presentation components in a cmd/ directory and delegate core orchestration to a dedicated pkg/ package. This separation enforces clean layer boundaries, enabling isolated testing and easier maintenance across large codebases.

The orchestrator pattern coordinates modular components through a central layer while keeping implementations isolated. It separates orchestration from implementation logic, improving testability and maintainability by ensuring core business rules remain independent of CLI or API presentation layers.

Structure a Go project for API and CLI reusability by implementing a dedicated orchestrator layer that delegates business logic to separate packages. Keeping CLI concerns in cmd/ allows the same core logic to be reused across API services and Cron or Workflow integrations.

Separating concerns significantly improves testability in multi-layer applications by isolating business logic from CLI and presentation layers. This clean separation allows developers to test core logic independently using fake clients, bypassing external dependencies during unit testing.

Yes, the orchestrator pattern works with Kubernetes client-go by isolating orchestration logic from implementation details. Using fake client sets from k8s.io/client-go/kubernetes/fake enables isolated testing of deployment logic without requiring a live cluster connection.

Avoid separation of concerns in small, single-purpose scripts where the overhead of a dedicated orchestrator layer and separate packages outweighs maintainability benefits. It is best suited for multi-layer software projects requiring coordination across CLI, API, and workflow integrations.