golang-dependency-injection

Manual constructor injection is ideal for small Go services, keeping wiring explicit in main.go without external dependencies. DI libraries like google/wire or uber-go/fx are recommended for large microservices to manage complex dependency graphs and lifecycle considerations efficiently.

Choose google/wire for compile-time generated dependency injection to catch wiring errors early, or uber-go/fx and samber/do for runtime injection to handle dynamic lifecycle management. This decision prevents tight coupling and hidden dependencies in your Go applications.

Structure your Go application by keeping the dependency container at the composition root and favoring lazy initialization. This prevents global registries and init() side effects, moving dependency resolution to explicit constructor functions for better maintainability.

You should avoid using a dependency injection container when manual constructor injection sufficiently covers your Go service's complexity. Over-engineering small services with heavy DI libraries adds unnecessary abstraction, whereas explicit wiring from configuration to transport keeps code simple.