gin

Gin

Gin is a high-performance HTTP web framework written in Go, featuring a fast radix-tree router, composable middleware chains, and structured request validation.

When to Use

• High-Throughput Go Microservices: Building low-latency web services with martini-like API and fast radx tree routing.
• JSON REST APIs: Serializing and deserializing payloads with strong validation and minimal allocation overhead.
• Microservice Middleware Stacks: Implementing custom logging, auth, rate limiting, and recovery middleware.
• File Upload & Static Asset Serving: Fast static asset handling and multipart streaming.

Quick Start

package main

import (
	"net/http"
	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()

	r.GET("/api/ping", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"message": "pong"})
	})

	r.Run(":8080")
}

Core Concepts

Radix Tree Routing & Parameter Binding

Fast route matching with typed model binding:

package main

import (
	"net/http"
	"github.com/gin-gonic/gin"
)

type CreateAccountRequest struct {
	Email    string `json:"email" binding:"required,email"`
	Password string `json:"password" binding:"required,min=8"`
}

func main() {
	r := gin.New()
	r.Use(gin.Logger())
	r.Use(gin.Recovery())

	v1 := r.Group("/api/v1")
	{
		v1.GET("/health", func(c *gin.Context) {
			c.JSON(http.StatusOK, gin.H{"status": "UP"})
		})

		v1.POST("/accounts", func(c *gin.Context) {
			var req CreateAccountRequest
			if err := c.ShouldBindJSON(&req); err != nil {
				c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
				return
			}
			c.JSON(http.StatusCreated, gin.H{"email": req.Email, "id": 1001})
		})
	}

	_ = r.Run(":8080")
}

Custom Middleware Pipeline

Intercepting requests and calculating execution latency:

package main

import (
	"log"
	"time"
	"github.com/gin-gonic/gin"
)

func LatencyTracker() gin.HandlerFunc {
	return func(c *gin.Context) {
		start := time.Now()
		c.Next() // Process subsequent handlers

		latency := time.Since(start)
		status := c.Writer.Status()
		log.Printf("[GIN] %s %s | %d | %v", c.Request.Method, c.Request.URL.Path, status, latency)
	}
}