golang-gin

Go + Gin

Overview

Gin is a high-performance HTTP web framework for Go. It provides routing, middleware, JSON validation, and rendering with minimal overhead.

Project Structure

cmd/
├── server/
│   └── main.go              # Entry point
internal/
├── config/
│   └── config.go            # Configuration loading
├── handler/
│   ├── auth.go              # Auth handlers
│   └── user.go              # User handlers
├── middleware/
│   ├── auth.go              # JWT middleware
│   └── cors.go              # CORS middleware
├── model/
│   └── user.go              # Domain models + DB structs
├── repository/
│   └── user_repo.go         # Database access
├── service/
│   └── user_service.go      # Business logic
└── router/
    └── router.go            # Route registration

Core Patterns

Router Setup

func SetupRouter(userHandler *handler.UserHandler, authMW gin.HandlerFunc) *gin.Engine {
    r := gin.Default()

    r.Use(middleware.CORS())

    api := r.Group("/api/v1")
    {
        auth := api.Group("/auth")
        auth.POST("/login", userHandler.Login)
        auth.POST("/register", userHandler.Register)

        users := api.Group("/users")
        users.Use(authMW)
        users.GET("/:id", userHandler.GetByID)
        users.PUT("/:id", userHandler.Update)
    }

    return r
}

Handlers

type UserHandler struct {
    service service.UserService
}

func (h *UserHandler) GetByID(c *gin.Context) {
    id := c.Param("id")
    user, err := h.service.GetByID(c.Request.Context(), id)
    if err != nil {
        c.JSON(http.StatusNotFound, gin.H{"error": "user not found"})
        return
    }
    c.JSON(http.StatusOK, user)
}

// Request binding with validation
type CreateUserRequest struct {
    Email    string `json:"email" binding:"required,email"`
    Password string `json:"password" binding:"required,min=8"`
    Name     string `json:"name" binding:"required,max=100"`
}

func (h *UserHandler) Register(c *gin.Context) {
    var req CreateUserRequest
    if err := c.ShouldBindJSON(&req); err != nil {
        c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
        return
    }
    // ... create user
}