[Go Course] Web FrameWork - Gin

Go 语言有非常的优秀的特性 (比如高并发、原生支持协程、泛型等等), 同时也贡献了非常多项目(可以 https://awesome-go.com/ 一览)，在 Web 开发这块也有非常多优秀的框架，如 Gin、Beego、Iris、Echo、Revel 等.
Top Go Web Frameworks

Gin

官方介绍
Gin is a web framework written in Go (Golang). It features a martini-like API with performance that is up to 40 times faster thanks to httprouter. If you need performance and good productivity, you will love Gin.

Scaffold (脚手架)

为了快速使用 Gin, 我提供了 Gin Scaffold 程序。
提供如下功能:

• ORM 封装 (使用的 GORM, 对 Model Interface 可进行继承设计, 可方便的封装 DAO 层)
• Tracing (支持链路追踪)
• Http TimeOut (支持 Http 请求超时中断)
• Swagger

支持部署:

• Docker
• Helm

ORM Interface 继承

设计 BaseModel, 在后面的业务 Model 继承这个 BaseModel 即可抽象 DAO interface

// base model
type BaseModel struct {
    ID        uint64 `json:"id,omitempty" gorm:"primarykey"`
    CreatedAt time.Time
    UpdatedAt time.Time
    DeletedAt gorm.DeletedAt `gorm:"index"`
}

// base dao
type BaseDAO interface {
    Create(entity interface{}) error
    Update(entity interface{}, uid uint64) (int64, error)
    Delete(entity interface{}, uid uint64) (int64, error)
    FindAll(entity interface{}, opts ...DAOOption) error
    FindByKeys(entity interface{}, keys map[string]interface{}) error
    FindByPages(entity interface{}, currentPage, pageSize int) error
    FindByPagesWithKeys(entity interface{}, keys map[string]interface{}, currentPage, pageSize int) error
    SearchByPagesWithKeys(entity interface{}, keys, keyOpts map[string]interface{}, currentPage, pageSize int) error
    Count(entity interface{}, count *int64) error
    CountWithKeys(entity interface{}, count *int64, keys, keyOpts map[string]interface{}) error
}

如 UserDAO 继承 BaseDAO, 然后编写 UserDAO 独有的业务 dao 方法

// instance entity
type User struct {
    ID           uint64         `json:"id,omitempty"`
    Name         string         `json:"name,omitempty" gorm:"type:varchar(255)"`
    Password     string         `json:"password,omitempty" gorm:"type:varchar(1000)"`
    Email        string         `json:"email,omitempty" gorm:"type:varchar(255)"`
    Age          int            `json:"age,omitempty"`
    Birthday     time.Time      `json:"birthday,omitempty"`
    MemberNumber sql.NullString `json:"member_number,omitempty" gorm:"type:varchar(255)"`
    Role         string         `json:"Role,omitempty" gorm:"type:varchar(100)"`
    BaseModel
}

// user DAO
type UserDAO interface {
    BaseDAO
    FindAllByCount(count int) ([]User, error)
}

Http Timeout

设计 TimeoutHandler middleware 来处理超时请求

const (
    TIME_DURATION = 10
)

func DefinitionRoute(router *gin.Engine) {
    // set run mode
    gin.SetMode(gin.DebugMode)
    // middleware
    router.Use(middleware.Tracing())
    router.Use(middleware.UseCookieSession())
    router.Use(middleware.TimeoutHandler(time.Second * TIME_DURATION))
    // no route
    router.NoRoute(NoRouteResponse)
    // home
    var userController *controller.UserController
    router.Static("/web/assets", "./web/assets")
    router.StaticFS("/web/upload", http.Dir("/web/upload"))
    router.LoadHTMLGlob("web/*.tmpl")
...

分布式链路 Jaeger

引入 traceandtrace-go 实现 Tracing middleware, 上报链路信息到 jaeger

import (
    "log"

    tracing "github.com/codeandcode0x/traceandtrace-go"
    "github.com/gin-gonic/gin"
)

// Tracing 中间件
func Tracing() gin.HandlerFunc {
    return func(c *gin.Context) {
        log.Println("..... tracing header1 ", c.Request.Header)
        // add tracing
        pctx, cancel := tracing.AddHttpTracing(
            "ticket-manager",
            c.Request.URL.String()+" "+c.Request.Method,
            c.Request.Header,
            map[string]string{
                "component":      "gin-server",
                "httpMethod":     c.Request.Method,
                "httpUrl":        c.Request.URL.String(),
                "proto":          c.Request.Proto,
                "peerService":    c.HandlerName(),
                "httpStatusCode": "200",
                "spanKind":       "server",
            })
        defer cancel()

        // deliver parent context
        c.Set("parentCtx", pctx)
        c.Next()
        return
    }
}

总结

• gin 在 go web 上使用非常方便, 并且性能非常不错
• 使用 gin 脚手架可以快速构建开发项目