golang 上基于标头的版本控制

router := gin.Default()

            v1 := router.Group("/v1")
            v1.Use(VersionMiddleware())
            v1.GET("/user/:id", func(c *gin.Context) {
                c.String(http.StatusOK, "This is the v1 API")
            })

            v2 := router.Group("/v2")
            v2.Use(VersionMiddleware())
            v2.GET("/user/:id", func(c *gin.Context) {
                c.String(http.StatusOK, "This is the v2 API")
            })

func VersionMiddleware() gin.HandlerFunc {
    return func(c *gin.Context) {
        version := c.Request.Header.Get(configuration.GetConfigValue("VersionHeader"))

        // Construct the new URL path based on the version number
        path := fmt.Sprintf("/%s%s", version, c.Request.URL.Path)

        // Modify the request URL path to point to the new version-specific endpoint
        c.Request.URL.Path = path
        c.Next()
    }
}

package main

import (
 "net/http"
 "net/http/httputil"
 "regexp"

 "github.com/gin-gonic/gin"
)



func main() {
 router := gin.default()
 router.use(versionmiddleware())


 v1 := router.group("/v1")
 v1.get("/user", func(c *gin.context) {
  c.string(http.statusok, "this is the v1 api")
 })

 v2 := router.group("/v2")
 v2.get("/user", func(c *gin.context) {
  c.string(http.statusok, "this is the v2 api")
 })

 router.run(":8082")
}



func versionmiddleware() gin.handlerfunc {
    return func(c *gin.context) {
  
  // you need to check c.request.url.path whether 
  // already have a version or not, if it has a valid
  // version, return.
  regex, _ := regexp.compile("/v[0-9]+")
  ver := regex.matchstring(c.request.url.path)
  if ver {
   return
  }

  version := c.request.header.get("accept-version")
  
  // you need to validate  given version by the user here.
  // if version is not a valid version, return error 
  // mentioning that given version is invalid.

  director := func(req *http.request) {
    r := c.request
    req.url.scheme = "http"
    req.url.host = r.host
    req.url.path =  "/"+ version + r.url.path
    }
  proxy := &httputil.reverseproxy{director: director}
  proxy.servehttp(c.writer, c.request)
 }
}

package main

import (
 "net/http"

 "github.com/gin-gonic/gin"
 "github.com/udayangaac/stackoverflow/golang/75860989/ginwrapper"
)



func main() {
  engine := gin.default()
 router := ginwrapper.newrouter(engine)

 defaultrouter := router.default()
 defaultrouter.get("/profile",func(ctx *gin.context) {

 })

 v1 := router.withversion("/v1")
 v1.get("/user",func(ctx *gin.context) {
  ctx.string(http.statusok, "this is the profile v1 api")
 })

 v2 := router.withversion("/v2")
 v2.get("/user",func(ctx *gin.context) {
  ctx.string(http.statusok, "this is the profile v2 api")
 })

 
 engine.run(":8082")
}

package ginwrapper

import (
 "fmt"
 "net/http"

 "github.com/gin-gonic/gin"
)

type router struct {
 router *gin.engine
 versiongroups map[string]*gin.routergroup
}

type versionedrouter struct {
 version string
 router
}

func newrouter(router *gin.engine) *router {
 return &router{
  router: router,
  versiongroups: make(map[string]*gin.routergroup),
 }
}

func (a *router) default() versionedrouter {
 return versionedrouter{router: *a }
}

func  (a *router) withversion(version string) versionedrouter {
 if _,ok := a.versiongroups[version]; ok {
  panic("cannot initialize same version multiple times")
 }
 a.versiongroups[version] = a.router.group(version)
 return versionedrouter{router: *a,version:version }
}




func (vr versionedrouter) get(relativepath string, handlers ...gin.handlerfunc)  {
 vr.handle(http.methodget,relativepath,handlers...)
}

// note: you need to follow the same for other http methods.
// as an example, we can write a method for post http method as below,
// 
//  func (vr versionedrouter) post(relativepath string, handlers ...gin.handlerfunc)  {
//   vr.handle(http.methodpost,relativepath,handlers...)
//  }





func (vr versionedrouter)handle(method,relativepath string, handlers ...gin.handlerfunc)  {
 if !vr.isrouteexist(method,relativepath) {
  vr.router.handle(method,relativepath,func(ctx *gin.context) {
   version := ctx.request.header.get("accept-version")
   if len(version) == 0 {
    ctx.string(http.statusbadrequest,"accept-version header is empty")
   }
   ctx.request.url.path = fmt.sprintf("/%s%s", version, ctx.request.url.path)
   vr.router.handlecontext(ctx)
  })
 }

 versionedrelativepath := vr.version + relativepath
 if !vr.isrouteexist(method,versionedrelativepath) {
  vr.router.handle(method,versionedrelativepath,handlers... )
 }
}


func (a versionedrouter) isrouteexist(method,relativepath string) bool {
 for _,route := range a.router.routes() {
  if route.method == method && relativepath == route.path {
   return true
  } 
 }
 return false
}

curl --location 'localhost:8082/user' \
--header 'accept-version: v1'

curl --location 'localhost:8082/user' \
--header 'Accept-version: v2'