1.前言

Go 语言是一种表达能力非常强大的语言。目前有一个Golang实现的restful webservice 包，go-restful使用起来很简单。

2.Demo

例子实现了一个查询操作，更详细的Demo见这里：https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go

package main

import (
	"log"
	"net/http"
	//"strconv"
	"github.com/emicklei/go-restful"
	"github.com/emicklei/go-restful/swagger"
)

type User struct {
	Id,Name string
}

type UserResource struct {

	users map[string]User
}

func (u UserResource) Register(container *restful.Container) {
	ws := new(restful.WebService)

	ws.
		Path("/users").
		Doc("Manage Users").
		Consumes(restful.MIME_XML,restful.MIME_JSON).
		Produces(restful.MIME_JSON,restful.MIME_XML)

	ws.Route(ws.GET("/{user-id}").To(u.findUser).
		// docs
		Doc("get a user").
		Operation("findUser").
		Param(ws.PathParameter("user-id","identifier of the user").DataType("string")).
		Writes(User{})) // on the response

	container.Add(ws)
}

func (u UserResource) findUser(request *restful.Request,response *restful.Response) {
	id := request.PathParameter("user-id")
	usr := u.users[id]
	if len(usr.Id) == 0 {
		response.AddHeader("Content-Type","text/plain")
		response.WriteErrorString(http.StatusNotFound,"404: User could not be found.")
		return
	}
	response.WriteEntity(usr)
}

func main () {

	wsContainer := restful.NewContainer()

	userMap := map[string]User{
		"1":User{"1","tom"},"2":User{"2","jerry"},}

	u := UserResource{userMap}
	u.Register(wsContainer)

	config := swagger.Config{
		WebServices:    wsContainer.RegisteredWebServices(),// you control what services are visible
		WebServicesUrl: "http://localhost:8080",ApiPath:        "/apidocs.json",// Optionally,specifiy where the UI is located
		SwaggerPath:     "/apidocs/",SwaggerFilePath: "/Users/emicklei/xProjects/swagger-ui/dist"}
	swagger.RegisterSwaggerService(config,wsContainer)

	log.Printf("start listening on localhost:8080")
	server := &http.Server{Addr: ":8080",Handler: wsContainer}
	log.Fatal(server.ListenAndServe())
}

Golang 中的go-restful 库在k8s中作为apiserver的rest框架来实现，实现路由和handler的对接，功能很完善。