Twitter - Go/Golang 框架 Echo 文档

类似 Twitter 的 API 服务

这个示例演示如何使用 MongoDB，JWT 和 JSON 创建一个类似 Twitter 的 REST API 服务。

模型

user.go

package model

import "gopkg.in/mgo.v2/bson"

type (
	User struct {
		ID        bson.ObjectId `json:"id" bson:"_id,omitempty"`
		Email     string        `json:"email" bson:"email"`
		Password  string        `json:"password,omitempty" bson:"password"`
		Token     string        `json:"token,omitempty" bson:"-"`
		Followers []string      `json:"followers,omitempty" bson:"followers,omitempty"`
	}
)

post.go

package model

import "gopkg.in/mgo.v2/bson"

type (
	Post struct {
		ID      bson.ObjectId `json:"id" bson:"_id,omitempty"`
		To      string        `json:"to" bson:"to"`
		From    string        `json:"from" bson:"from"`
		Message string        `json:"message" bson:"message"`
	}
)

控制器

handler.go

package handler

import mgo "gopkg.in/mgo.v2"

type (
	Handler struct {
		DB *mgo.Session
	}
)

const (
	// Key (Should come from somewhere else).
	Key = "secret"
)

user.go

package handler

import (
	"net/http"
	"time"

	jwt "github.com/dgrijalva/jwt-go"
	"github.com/labstack/echo"
	"github.com/labstack/echo/cookbook/twitter/model"
	mgo "gopkg.in/mgo.v2"
	"gopkg.in/mgo.v2/bson"
)

func (h *Handler) Signup(c echo.Context) (err error) {
	// Bind
	u := &model.User{ID: bson.NewObjectId()}
	if err = c.Bind(u); err != nil {
		return
	}

	// Validate
	if u.Email == "" || u.Password == "" {
		return &echo.HTTPError{Code: http.StatusBadRequest, Message: "invalid email or password"}
	}

	// Save user
	db := h.DB.Clone()
	defer db.Close()
	if err = db.DB("twitter").C("users").Insert(u); err != nil {
		return
	}

	return c.JSON(http.StatusCreated, u)
}

func (h *Handler) Login(c echo.Context) (err error) {
	// Bind
	u := new(model.User)
	if err = c.Bind(u); err != nil {
		return
	}

	// Find user
	db := h.DB.Clone()
	defer db.Close()
	if err = db.DB("twitter").C("users").
		Find(bson.M{"email": u.Email, "password": u.Password}).One(u); err != nil {
		if err == mgo.ErrNotFound {
			return &echo.HTTPError{Code: http.StatusUnauthorized, Message: "invalid email or password"}
		}
		return
	}

	//-----
	// JWT
	//-----

	// Create token
	token := jwt.New(jwt.SigningMethodHS256)

	// Set claims
	claims := token.Claims.(jwt.MapClaims)
	claims["id"] = u.ID
	claims["exp"] = time.Now().Add(time.Hour * 72).Unix()

	// Generate encoded token and send it as response
	u.Token, err = token.SignedString([]byte(Key))
	if err != nil {
		return err
	}

	u.Password = "" // Don't send password
	return c.JSON(http.StatusOK, u)
}

func (h *Handler) Follow(c echo.Context) (err error) {
	userID := userIDFromToken(c)
	id := c.Param("id")

	// Add a follower to user
	db := h.DB.Clone()
	defer db.Close()
	if err = db.DB("twitter").C("users").
		UpdateId(bson.ObjectIdHex(id), bson.M{"$addToSet": bson.M{"followers": userID}}); err != nil {
		if err == mgo.ErrNotFound {
			return echo.ErrNotFound
		}
	}

	return
}

func userIDFromToken(c echo.Context) string {
	user := c.Get("user").(*jwt.Token)
	claims := user.Claims.(jwt.MapClaims)
	return claims["id"].(string)
}

post.go

package handler

import (
	"net/http"
	"strconv"

	"github.com/labstack/echo"
	"github.com/labstack/echo/cookbook/twitter/model"
	mgo "gopkg.in/mgo.v2"
	"gopkg.in/mgo.v2/bson"
)

func (h *Handler) CreatePost(c echo.Context) (err error) {
	u := &model.User{
		ID: bson.ObjectIdHex(userIDFromToken(c)),
	}
	p := &model.Post{
		ID:   bson.NewObjectId(),
		From: u.ID.Hex(),
	}
	if err = c.Bind(p); err != nil {
		return
	}

	// Validation
	if p.To == "" || p.Message == "" {
		return &echo.HTTPError{Code: http.StatusBadRequest, Message: "invalid to or message fields"}
	}

	// Find user from database
	db := h.DB.Clone()
	defer db.Close()
	if err = db.DB("twitter").C("users").FindId(u.ID).One(u); err != nil {
		if err == mgo.ErrNotFound {
			return echo.ErrNotFound
		}
		return
	}

	// Save post in database
	if err = db.DB("twitter").C("posts").Insert(p); err != nil {
		return
	}
	return c.JSON(http.StatusCreated, p)
}

func (h *Handler) FetchPost(c echo.Context) (err error) {
	userID := userIDFromToken(c)
	page, _ := strconv.Atoi(c.QueryParam("page"))
	limit, _ := strconv.Atoi(c.QueryParam("limit"))

	// Defaults
	if page == 0 {
		page = 1
	}
	if limit == 0 {
		limit = 100
	}

	// Retrieve posts from database
	posts := []*model.Post{}
	db := h.DB.Clone()
	if err = db.DB("twitter").C("posts").
		Find(bson.M{"to": userID}).
		Skip((page - 1) * limit).
		Limit(limit).
		All(&posts); err != nil {
		return
	}
	defer db.Close()

	return c.JSON(http.StatusOK, posts)
}

API

注册

用户注册

用请求里取出用户信息验证合法性。
不合法的邮箱和密码，返回 400 - Bad Request。
合法的邮箱和密码，保存数据到数据库并返回 201 - Created。

请求

curl \
  -X POST \
  http://localhost:1323/signup \
  -H "Content-Type: application/json" \
  -d '{"email":"jon@labstack.com","password":"shhh!"}'

响应

201 - Created

{
  "id": "58465b4ea6fe886d3215c6df",
  "email": "jon@labstack.com",
  "password": "shhh!"
}

User login

Retrieve user credentials from the body and validate against database.
For invalid credentials, send 401 - Unauthorized response.
For valid credentials, send 200 - OK response:
- Generate JWT for the user and send it as response.
- Each subsequent request must include JWT in the Authorization header.

Method: POST
Path: /login

Request

curl \
  -X POST \
  http://localhost:1323/login \
  -H "Content-Type: application/json" \
  -d '{"email":"jon@labstack.com","password":"shhh!"}'

Response

200 - OK

{
  "id": "58465b4ea6fe886d3215c6df",
  "email": "jon@labstack.com",
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0ODEyNjUxMjgsImlkIjoiNTg0NjViNGVhNmZlODg2ZDMyMTVjNmRmIn0.1IsGGxko1qMCsKkJDQ1NfmrZ945XVC9uZpcvDnKwpL0"
}

Client should store the token, for browsers, you may use local storage.

Follow

Follow a user

For invalid token, send 400 - Bad Request response.
For valid token:
- If user is not found, send 404 - Not Found response.
- Add a follower to the specified user in the path parameter and send 200 - OK response.

Method: POST
Path: /follow/:id

Request

curl \
  -X POST \
  http://localhost:1323/follow/58465b4ea6fe886d3215c6df \
  -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0ODEyNjUxMjgsImlkIjoiNTg0NjViNGVhNmZlODg2ZDMyMTVjNmRmIn0.1IsGGxko1qMCsKkJDQ1NfmrZ945XVC9uZpcvDnKwpL0"

Response

200 - OK

Post

Post a message to specified user

For invalid request payload, send 400 - Bad Request response.
If user is not found, send 404 - Not Found response.
Otherwise save post in the database and return it via 201 - Created response.

Method: POST
Path: /posts

Request

curl \
  -X POST \
  http://localhost:1323/posts \
  -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0ODEyNjUxMjgsImlkIjoiNTg0NjViNGVhNmZlODg2ZDMyMTVjNmRmIn0.1IsGGxko1qMCsKkJDQ1NfmrZ945XVC9uZpcvDnKwpL0" \
  -H "Content-Type: application/json" \
  -d '{"to":"58465b4ea6fe886d3215c6df","message":"hello"}'

Response

201 - Created

{
  "id": "584661b9a6fe8871a3804cba",
  "to": "58465b4ea6fe886d3215c6df",
  "from": "58465b4ea6fe886d3215c6df",
  "message": "hello"
}

Feed

List most recent messages based on optional page and limit query parameters

Method: GET
Path: /feed?page=1&limit=5

Request

curl \
  -X GET \
  http://localhost:1323/feed \
  -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0ODEyNjUxMjgsImlkIjoiNTg0NjViNGVhNmZlODg2ZDMyMTVjNmRmIn0.1IsGGxko1qMCsKkJDQ1NfmrZ945XVC9uZpcvDnKwpL0"

Response

200 - OK

[
  {
    "id": "584661b9a6fe8871a3804cba",
    "to": "58465b4ea6fe886d3215c6df",
    "from": "58465b4ea6fe886d3215c6df",
    "message": "hello"
  }
]