How to Structure a Go Microservice

Structure a Go microservice by separating concerns into distinct packages for handlers, business logic, and configuration, then initialize dependencies in main.go before starting the server.

package main

import (
	"log"
	"net/http"
	"your-service/internal/handler"
	"your-service/internal/config"
)

func main() {
	cfg := config.Load()
	h := handler.New(cfg)
	log.Fatal(http.ListenAndServe(cfg.Addr, h.Mux))
}

1. Create a config package to load environment variables and define a configuration struct.
2. Create an internal/handler package to define HTTP handlers and register routes on an http.ServeMux.
3. Create an internal/service package to encapsulate business logic and database interactions.
4. In main.go, instantiate the configuration, initialize the service layer, create handlers with the service, and start the HTTP server.

A Go microservice is a small, independent program that handles one specific task, like processing payments or managing users. You structure it by keeping code for web requests, business rules, and settings in separate folders so each part is easy to update without breaking the others. Think of it like a restaurant kitchen where the ordering, cooking, and billing stations are separate but work together to serve a customer.