1.前言

Go 語言是一種表達能力非常強大的語言。目前有一個Golang實現的restful webservice 包，go-restful使用起來很簡單。

2.Demo

例子實現了一個查詢操作，更詳細的Demo見這裡：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 庫在k8s中作為apiserver的rest框架來實現，實現路由和handler的對接，功能很完善。