构建API服务器1

本文来源于ruby-china
https://ruby-china.org/topics/25822

1. 新建项目

rails new build-an-api-rails-demo

2. 生成控制器

#不生成资源文件
rails g controller api/v1/base --no-assets

编辑 app/controller/api/v1/base_controller.rb

class Api::V1::BaseController < ApplicationController
  #disable the CSRF token
  protect_from_forgery with: :null_session
  #protect_form_forgery :with => :null_session

  #disable the cookies (no set-cookies header in response)
  before_action :destroy_session

  #disable the CSRF token
  skip_before_action :verify_authenticity_token

  def destroy_session
    request.session_options[:skip] = true
  end
end

在BaseController中禁止了CSRF token 和cookies⬆️

3.配置路由

namespace :api do
  namespace :v1 do
    resources :users, only: [:index, :create, :show, :update, :destroy]
    #⬆️⬇️两种写法是等价的
    #resources :users, :only => [:index, :create, :show, :update, :destroy]
  end
end

4. 生成控制器(UsersController)

rails g controller api/v1/users --no-assets

编辑app/controller/api/v1/users_controller.rb

class Api::V1::UsersController < Api::V1::BaseController
  def show
    @user = User.find(params[:id])
  end
end

编辑app/views/api/v1/users/show.json.jbuilder

json.user do
  json.(@user, :id, :email, :name, :activated, :admin, :created_at, :updated_at)
end

5. 建立User模型和users表

rails g model User

app/models/user.rb

class User < ActiveRecord::Base
end

db/migrate/****_create_users.rb

class CreateUsers < ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.string :email
      t.string :name
      t.datetime :activated
      t.boolean :admin, default: false
      t.timestamps null: false
    end
  end
end

6. 生成测试数据

db/seeds.rb

users = User.create([
  {
    email: '[email protected]',
    name: 'test01',
    activated: DateTime.now,
    admin: false
  },
  {
    email: '[email protected]',
    name: 'test02',
    activated: DateTime.now,
    admin: false
  }  
])

创建种子数据

rake db:seed

7. 运行服务器并测试

rails s -b 0.0.0.0
#
curl -i http://localhost:3000/api/v1/users/1.json

8. 增加认证过程

上述的过程并没有用户认证,可以直接获取用户信息,这是不安全的.

认证过程是这样的,用户把用户名和密码通过HTTP POST请求发送到API,如果用户名和密码匹配,我们就会把token发送给用户。这个token就是用来证明用户身份的凭证。然后在以后的每个请求中,我们通过这个token来查找用户,如果没有找到就返回401错误

#给User模型增加authentication_token属性
rails g migration add_authentication_token_to_users

db/migrate/***_add_authentication_token_to_users.rb

class AddAuthenticationTokenToUsers < ActiveRecord::Migration
  def change
    add_column :users, :authentication_token, :string
  end
end
rake db:migrate

生成authentication_token
app/model/user.rb

class User < ActiveRecord::Base
  before_create :generate_authentication_token

  def generate_authentication_token
    loop do
      self.authentication_token = SecureRandom.base64(64)
      break if !User.find_by(authentication_token: authentication_token)
    end
  end

  def reset_auth_token!
    generate_authentication_token
    save
  end
end

9. 生成session控制器(用户认证用)

rails g controller api/v1/sessions --no-assets

app/controller/api/v1/sessions_controller.rb

class Api::V1::SessionsController < Api::V1::BaseController
  def create
    @user = User.find_by(email: create_params[:email])
    #authenticate是bcrypt这个Gem包中的方法
    if @user && @user.authenticate(create_params[:password])
      self.current_user = @user
    else
      return api_error(status: 401)
    end
  end
  private
  def create_params
    params.require(:user).permit(:email, :password)
  end
end

10. 给User模型增加password相关属性

在Gemfile里将gem 'bcrypt'

#Use ActiveModel has_secure_password
gem 'bcrypt'

app/models/user.rb

class User < ActiveRecord::Base
  #加这句话user有password属性,对应表字段password_digest
  #可以用user.password = "123",自动转化为加密字符串
  +has_secure_password
end

给User模型增加password_digest属性

rails g migration add_password_digest_to_users

db/migratie/***_add_password_to_users

class AddPasswordDigestToUsers < ActiveRecord::Migration
  def change
    add_column :users, :password_digest, :string
  end
end
rake db:migrate

给数据库中已存在的测试用户增加密码和authentication token

#在rails console中执行,但是console不能执行多行。所以这个意思
User.all.each {|user| user.password = '123123' user.reset_auth_token!  
                user.save }

实现current_user方法

app/controller/api/v1/base_controller.rb

class Api::V1::BaseController < ApplicationController
  + attr_accessor :current_user
end

实现app/views/api/v1/sessions/create.json.jbuilder

#返回用户信息和access_token,后续根据access_token就可以访问
json.session do
  json.(@user, :id, :name, :admin)
  json.token @user.authentication_token
end

实现api_err

class Api::V1::BaseController < ApplicationController 
  + def api_error(opts = {}) 
    + render nothing: true, status: opts[:status] 
  + end
end

api_error(status: 401)

11. 验证用户token

class Api::V1::BaseController < ApplicationController
+  def authenticate_user!   
+    token, options = ActionController::HttpAuthentication::Token.token_an_options
+    user_email = options.blank?? nil : options[:email]
+    user = user_email && User.find_by(email: user_email)
    
+    if user && ActiveSupport::SecurityUtils.secure_compare(user.authentication_token, token)
+      self.current_user = user
+    else
+      return unauthenticated!
+    end    
+  end
end

英语小课堂

authenticity  n. 真实性,确实性;可靠性
authentication n. 证明;鉴定;证实

你可能感兴趣的:(构建API服务器1)