Go实战--golang中使用Goji微框架(Goji+Mongodb构建微服务)

生命不止，继续 go go go!!!

今天跟大家分享一个web微框架Goji.

Goji

What is Goji?

枸杞？

Goji is a HTTP request multiplexer,similar to net/http.ServeMux. It compares incoming requests to a list of registered Patterns,and dispatches to the Handler that corresponds to the first matching Pattern. Goji also supports Middleware (composable shared functionality applied to every request) and uses the standard context to store request-scoped values.

官网：
https://goji.io/

github地址：
https://github.com/goji/goji

Star:
577

文档地址：
https://godoc.org/goji.io

获取：
go get goji.io

示例：

package main

import (
    "fmt"
    "net/http"

    "goji.io"
    "goji.io/pat"
)

func hello(w http.ResponseWriter,r *http.Request) {
    name := pat.Param(r,"name")
    fmt.Fprintf(w,"Hello,%s!",name)
}

func main() {
    mux := goji.NewMux()
    mux.HandleFunc(pat.Get("/hello/:name"),hello)

    http.ListenAndServe("localhost:8000",mux)
}

运行，浏览器访问：http://localhost:8000/hello/heyGoji
返回：Hello,heyGoji!

zenazn/goji

不要奇怪， zenazn/goji is new version of Goji，也就是一个作者。
This project has been superseded by a new version of Goji by the same author,which has very similar primitives and semantics,but has been updated to reflect several years of experience with this library and the surrounding Go ecosystem. This project is still well-loved and well-maintained,and will be for the foreseeable future,but new projects are encouraged to use goji.io instead.

Goji是一个用Go语言写的Web微框架。Goji的设计理念是简单、可组合性、自由。它具有以下特点：

• 兼容net/http
• url模式（同时支持 Sinatra 风格的 /foo/:bar 和 正则表达式）
• 可重构中间件栈
• 通过中间件和处理器处理上下文/环境对象
• 自动支持 Einhorn、systemd等
• 渐进停止，配合 Einhorn 可实现零下线时间的渐进重载

github地址：
https://github.com/zenazn/goji

Star:
3354

获取：
go get github.com/zenazn/goji

示例：

package main

import (
    "fmt"
    "net/http"

    "github.com/zenazn/goji"
    "github.com/zenazn/goji/web"
)

func hello(c web.C,w http.ResponseWriter,r *http.Request) {
    fmt.Fprintf(w,c.URLParams["name"])
}

func main() {
    goji.Get("/hello/:name",hello)
    goji.Serve()
}

运行：
2017/12/20 10:37:27.132172 Starting Goji on [::]:8000
2017/12/20 10:37:36.423659 [LAPTOP-MNU6522J/9tNAt5dWFL-000001] Started GET “/hello/heyGoji” from [::1]:19489
2017/12/20 10:37:36.423659 [LAPTOP-MNU6522J/9tNAt5dWFL-000001] Returning 200 in 0s

浏览器访问：http://localhost:8000/hello/heyGoji
返回：Hello,heyGoji!

应用

文件服务

package main

import (
    "fmt"
    "net/http"

    "github.com/zenazn/goji"
    "github.com/zenazn/goji/web"
)

func apiExampleHandler(context web.C,resp http.ResponseWriter,req *http.Request) {
    fmt.Fprint(resp,"You've hit the API!")
}

func main() {
    goji.Handle("/api",apiExampleHandler)

    // Static file handler should generally be the last handler registered. Otherwise,it'll match every path.
    // Be sure to use an absolute path.
    staticFilesLocation := "./"
    goji.Handle("/*",http.FileServer(http.Dir(staticFilesLocation)))

    goji.Serve()
}

运行，浏览器输入http://localhost:8000/

Goji Restful Api

package main

import (
    "encoding/json"
    "fmt"
    "net/http"

    "goji.io"
    "goji.io/pat"
)

type book struct {
    ISBN    string "json:isbn"
    Title   string "json:name"
    Authors string "json:author"
    Price   string "json:price"
}

var bookStore = []book{
    book{
        ISBN:    "0321774639",Title:   "Programming in Go: Creating Applications for the 21st Century (Developer's Library)",Authors: "Mark Summerfield",Price:   "$34.57",},book{
        ISBN:    "0134190440",Title:   "The Go Programming Language",Authors: "Alan A. A. Donovan,Brian W. Kernighan",}

func main() {
    mux := goji.NewMux()
    mux.HandleFunc(pat.Get("/books"),allBooks)
    mux.HandleFunc(pat.Get("/books/:isbn"),bookByISBN)
    mux.Use(logging)
    http.ListenAndServe("localhost:8080",mux)
}

func allBooks(w http.ResponseWriter,r *http.Request) {
    jsonOut,_ := json.Marshal(bookStore)
    fmt.Fprintf(w,string(jsonOut))
}

func bookByISBN(w http.ResponseWriter,r *http.Request) {
    isbn := pat.Param(r,"isbn")
    for _,b := range bookStore {
        if b.ISBN == isbn {
            jsonOut,_ := json.Marshal(b)
            fmt.Fprintf(w,string(jsonOut))
            return
        }
    }
    w.WriteHeader(http.StatusNotFound)
}

func logging(h http.Handler) http.Handler {
    fn := func(w http.ResponseWriter,r *http.Request) {
        fmt.Printf("Received request: %vn",r.URL)
        h.ServeHTTP(w,r)
    }
    return http.HandlerFunc(fn)
}

浏览器访问：
http://localhost:8080/books

返回：

// 20171220105345
// http://localhost:8080/books

Array[2][
  {
    "ISBN": "0321774639","Title": "Programming in Go: Creating Applications for the 21st Century (Developer's Library)","Authors": "Mark Summerfield","Price": "$34.57"
  },{
    "ISBN": "0134190440","Title": "The Go Programming Language","Authors": "Alan A. A. Donovan,"Price": "$34.57"
  }
]

认证
goji/httpauth
github地址：
https://github.com/goji/httpauth

获取：
go get github.com/goji/httpauth

package main

import (
    "net/http"

    "github.com/goji/httpauth"
    "github.com/zenazn/goji"
)

func main() {

    goji.Use(httpauth.SimpleBasicAuth("dave","password"))

    // myHandler requires HTTP Basic Auth to access
    goji.Get("/thing",myHandler)

    goji.Serve()
}

Goji+Mongodb搭建微服务

出自：
http://goinbigdata.com/how-to-build-microservice-with-mongodb-in-golang/

golang中如何使用mongodb，我们之前多次介绍过了，可以翻看之前的博客。
启动mongodb server：

mongod.exe --dbpath d:mongodb_datadb

直接上代码：

package main

import (
    "encoding/json"
    "fmt"
    "log"
    "net/http"

    "goji.io"
    "goji.io/pat"
    "gopkg.in/mgo.v2"
    "gopkg.in/mgo.v2/bson"
)

func ErrorWithJSON(w http.ResponseWriter,message string,code int) {
    w.Header().Set("Content-Type","application/json; charset=utf-8")
    w.WriteHeader(code)
    fmt.Fprintf(w,"{message: %q}",message)
}

func ResponseWithJSON(w http.ResponseWriter,json []byte,"application/json; charset=utf-8")
    w.WriteHeader(code)
    w.Write(json)
}

type Book struct {
    ISBN    string   `json:"isbn"`
    Title   string   `json:"title"`
    Authors []string `json:"authors"`
    Price   string   `json:"price"`
}

func main() {
    session,err := mgo.Dial("localhost")
    if err != nil {
        panic(err)
    }
    defer session.Close()

    session.SetMode(mgo.Monotonic,true)
    ensureIndex(session)

    mux := goji.NewMux()
    mux.HandleFunc(pat.Get("/books"),allBooks(session))
    mux.HandleFunc(pat.Post("/books"),addBook(session))
    mux.HandleFunc(pat.Get("/books/:isbn"),bookByISBN(session))
    mux.HandleFunc(pat.Put("/books/:isbn"),updateBook(session))
    mux.HandleFunc(pat.Delete("/books/:isbn"),deleteBook(session))
    http.ListenAndServe("localhost:8080",mux)
}

func ensureIndex(s *mgo.Session) {
    session := s.Copy()
    defer session.Close()

    c := session.DB("store").C("books")

    index := mgo.Index{
        Key:        []string{"isbn"},Unique:     true,DropDups:   true,Background: true,Sparse:     true,}
    err := c.EnsureIndex(index)
    if err != nil {
        panic(err)
    }
}

func allBooks(s *mgo.Session) func(w http.ResponseWriter,r *http.Request) {
    return func(w http.ResponseWriter,r *http.Request) {
        session := s.Copy()
        defer session.Close()

        c := session.DB("store").C("books")

        var books []Book
        err := c.Find(bson.M{}).All(&books)
        if err != nil {
            ErrorWithJSON(w,"Database error",http.StatusInternalServerError)
            log.Println("Failed get all books: ",err)
            return
        }

        respBody,err := json.MarshalIndent(books,""," ")
        if err != nil {
            log.Fatal(err)
        }

        ResponseWithJSON(w,respBody,http.StatusOK)
    }
}

func addBook(s *mgo.Session) func(w http.ResponseWriter,r *http.Request) {
        session := s.Copy()
        defer session.Close()

        var book Book
        decoder := json.NewDecoder(r.Body)
        err := decoder.Decode(&book)
        if err != nil {
            ErrorWithJSON(w,"Incorrect body",http.StatusBadRequest)
            return
        }

        c := session.DB("store").C("books")

        err = c.Insert(book)
        if err != nil {
            if mgo.IsDup(err) {
                ErrorWithJSON(w,"Book with this ISBN already exists",http.StatusBadRequest)
                return
            }

            ErrorWithJSON(w,http.StatusInternalServerError)
            log.Println("Failed insert book: ",err)
            return
        }

        w.Header().Set("Content-Type","application/json")
        w.Header().Set("Location",r.URL.Path+"/"+book.ISBN)
        w.WriteHeader(http.StatusCreated)
    }
}

func bookByISBN(s *mgo.Session) func(w http.ResponseWriter,r *http.Request) {
        session := s.Copy()
        defer session.Close()

        isbn := pat.Param(r,"isbn")

        c := session.DB("store").C("books")

        var book Book
        err := c.Find(bson.M{"isbn": isbn}).One(&book)
        if err != nil {
            ErrorWithJSON(w,http.StatusInternalServerError)
            log.Println("Failed find book: ",err)
            return
        }

        if book.ISBN == "" {
            ErrorWithJSON(w,"Book not found",http.StatusNotFound)
            return
        }

        respBody,err := json.MarshalIndent(book,http.StatusOK)
    }
}

func updateBook(s *mgo.Session) func(w http.ResponseWriter,"isbn")

        var book Book
        decoder := json.NewDecoder(r.Body)
        err := decoder.Decode(&book)
        if err != nil {
            ErrorWithJSON(w,http.StatusBadRequest)
            return
        }

        c := session.DB("store").C("books")

        err = c.Update(bson.M{"isbn": isbn},&book)
        if err != nil {
            switch err {
            default:
                ErrorWithJSON(w,http.StatusInternalServerError)
                log.Println("Failed update book: ",err)
                return
            case mgo.ErrNotFound:
                ErrorWithJSON(w,http.StatusNotFound)
                return
            }
        }

        w.WriteHeader(http.StatusNoContent)
    }
}

func deleteBook(s *mgo.Session) func(w http.ResponseWriter,"isbn")

        c := session.DB("store").C("books")

        err := c.Remove(bson.M{"isbn": isbn})
        if err != nil {
            switch err {
            default:
                ErrorWithJSON(w,http.StatusInternalServerError)
                log.Println("Failed delete book: ",http.StatusNotFound)
                return
            }
        }

        w.WriteHeader(http.StatusNoContent)
    }
}

运行，使用curl post数据：

curl -X POST -H "Content-Type: application/json" -d '{"isbn": "0134190440","title": "The Go Programming Language","authors": ["Alan A. A. Donovan","Brian W. Kernighan"],"price": "$34.57"}' http://localhost:8080/books

读取：

curl -H "Content-Type: application/json" http://localhost:8080/books

返回：

[
  {
    "isbn": "0134190440","title": "The Go Programming Language","authors": [ "Alan A. A. Donovan","Brian W. Kernighan" ],"price": "$34.57" }
]