什么是 REST？ 六条设计规范定义了一个 REST 系统的特点: 客户端-服务器: 客户端和服务器之间隔离，服务器提供服务，客户端进行消费。 无状态: 从客户端到服务器的每个请求都必须包含理解请求所必需的信息。换句话说， 服务器不会存储客户端上一次请求的信息用来给下一次使用。 可缓存: 服务器必须明示客户端请求能否缓存。 分层系统: 客户端和服务器之间的通信应该以一种标准的方式，就是中间层代替服务器做出响应的时候，客户端不需要做任何变动。 统一的接口: 服务器和客户端的通信方法必须是统一的。 按需编码: 服务器可以提供可执行代码或脚本，为客户端在它们的环境中执行。这个约束是唯一一个是可选的。 什么是一个 RESTful 的 web service？ REST 架构的最初目的是适应万维网的 HTTP 协议。 RESTful web services 概念的核心就是“资源”。 资源可以用 URI 来表示。客户端使用 HTTP 协议定义的方法来发送请求到这些 URIs，当然可能会导致这些被访问的”资源“状态的改变。 如下示例格式： ========== =============================================== ============================= HTTP 方法 URL 动作 ========== =============================================== ============================== GET http://[hostname]/devops/api/v1.0/tasks 检索任务列表 GET http://[hostname]/devops/api/v1.0/tasks/[task_id] 检索某个任务 POST http://[hostname]/devops/api/v1.0/tasks 创建新任务 PUT http://[hostname]/devops/api/v1.0/tasks/[task_id] 更新任务 DELETE http://[hostname]/devops/api/v1.0/tasks/[task_id] 删除任务 ##我们定义的任务有如下一些属性: id: 任务的唯一标识符。数字类型。 title: 简短的任务描述。字符串类型。 description: 具体的任务描述。文本类型。 done: 任务完成的状态。布尔值。 目前为止关于我们的 web service 的设计基本完成。剩下的事情就是实现它！ 第一个示例Get请求： [root@localhost opt]# cat test.py from flask import Flask, jsonify app = Flask(__name__) tasks = [ { 'id': 1, 'title': u'Buy groceries', 'description': u'Milk, Cheese, Pizza, Fruit, Tylenol', 'done': False }, { 'id': 2, 'title': u'Learn Python', 'description': u'Need to find a good Python tutorial on the web', 'done': False } ] @app.route('/todo/api/v1.0/tasks', methods=['GET']) def get_tasks(): return jsonify({'tasks': tasks}) if __name__ == '__main__': app.run(debug=True,host='0.0.0.0') #### [root@localhost ~]# curl -i http://localhost:5000/todo/api/v1.0/tasks HTTP/1.0 200 OK Content-Type: application/json Content-Length: 317 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:12:40 GMT { "tasks": [ { "description": "Milk, Cheese, Pizza, Fruit, Tylenol", "done": false, "id": 1, "title": "Buy groceries" }, { "description": "Need to find a good Python tutorial on the web", "done": false, "id": 2, "title": "Learn Python" } ] } ##返回json格式的结果。 2、接下来函数该子，当传入id 的时候，返回对应id 的结果： [root@localhost opt]# cat test.py from flask import Flask, jsonify, abort app = Flask(__name__) tasks = [ { 'id': 1, 'title': u'Buy groceries', 'description': u'Milk, Cheese, Pizza, Fruit, Tylenol', 'done': False }, { 'id': 2, 'title': u'Learn Python', 'description': u'Need to find a good Python tutorial on the web', 'done': False } ] @app.route('/todo/api/v1.0/tasks', methods=['GET']) @app.route('/todo/api/v1.0/tasks/<int:task_id>', methods=['GET']) def get_task(task_id=None): if task_id: task = [i for i in tasks if i['id']==task_id] print(task) if len(task) == 0: abort(404) return jsonify({'task': task}) else: return jsonify({'tasks': tasks}) if __name__ == '__main__': app.run(debug=True,host='0.0.0.0') ##测试结果： [root@localhost opt]# curl -i http://localhost:5000/todo/api/v1.0/tasks/3 HTTP/1.0 404 NOT FOUND Content-Type: text/html Content-Length: 232 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:30:56 GMT <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <title>404 Not Found</title> <h1>Not Found</h1> <p>The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.</p> [root@localhost opt]# curl -i http://localhost:5000/todo/api/v1.0/tasks/1 HTTP/1.0 200 OK Content-Type: application/json Content-Length: 162 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:31:00 GMT { "task": [ { "description": "Milk, Cheese, Pizza, Fruit, Tylenol", "done": false, "id": 1, "title": "Buy groceries" } ] } [root@localhost opt]# curl -i http://localhost:5000/todo/api/v1.0/tasks HTTP/1.0 200 OK Content-Type: application/json Content-Length: 317 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:31:02 GMT { "tasks": [ { "description": "Milk, Cheese, Pizza, Fruit, Tylenol", "done": false, "id": 1, "title": "Buy groceries" }, { "description": "Need to find a good Python tutorial on the web", "done": false, "id": 2, "title": "Learn Python" } ] } *当资源不存在的时候，返回404，但是这种返回效果不太好，为了优雅的线上，我们添加一个装饰器： from flask import make_response @app.errorhandler(404) def not_found(error): return make_response(jsonify({'error': 'Not found'}), 404) ###测试一下结构查询结果： [root@localhost opt]# curl -i http://localhost:5000/todo/api/v1.0/tasks/3 HTTP/1.0 404 NOT FOUND Content-Type: application/json Content-Length: 27 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:35:14 GMT { "error": "Not found" } 4、添加post请求： from flask import request @app.route('/todo/api/v1.0/tasks', methods=['POST']) def create_task(): if not request.json or not 'title' in request.json: abort(400) task = { 'id': tasks[-1]['id'] + 1, 'title': request.json['title'], 'description': request.json.get('description', ""), 'done': False } tasks.append(task) return jsonify({'task': task}), 201 ##先做判断没有收到json数据，或者没有title就返回400，并且返回201状态码 [root@localhost opt]# curl -i -H "Content-Type: application/json" -X POST -d '{"title":"Read a book"}' http://localhost:5000/todo/api/v1.0/tasks HTTP/1.0 201 CREATED Content-Type: application/json Content-Length: 105 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:38:52 GMT { "task": { "description": "", "done": false, "id": 3, "title": "Read a book" } } ##添加两条数据发现数据已经添加到了内存： [root@localhost opt]# curl -i http://localhost:5000/todo/api/v1.0/tasks HTTP/1.0 200 OK Content-Type: application/json Content-Length: 531 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:41:14 GMT { "tasks": [ { "description": "Milk, Cheese, Pizza, Fruit, Tylenol", "done": false, "id": 1, "title": "Buy groceries" }, { "description": "Need to find a good Python tutorial on the web", "done": false, "id": 2, "title": "Learn Python" }, { "description": "", "done": false, "id": 3, "title": "Read a book" }, { "description": "", "done": false, "id": 4, "title": "Read a book" } ] } ##剩余的PUT和DELETE方法： @app.route('/todo/api/v1.0/tasks/<int:task_id>', methods=['PUT']) def update_task(task_id): task = [i for i in tasks if i['id']==task_id] print(task) if len(task) == 0: abort(404) if not request.json: abort(400) if 'title' in request.json and type(request.json['title']) != unicode: abort(400) if 'description' in request.json and type(request.json['description']) is not unicode: abort(400) if 'done' in request.json and type(request.json['done']) is not bool: abort(400) task[0]['title'] = request.json.get('title', task[0]['title']) task[0]['description'] = request.json.get('description', task[0]['description']) task[0]['done'] = request.json.get('done', task[0]['done']) return jsonify({'task': task}) @app.route('/todo/api/v1.0/tasks/<int:task_id>', methods=['DELETE']) def delete_task(task_id): task = [i for i in tasks if i['id']==task_id] if len(task) == 0: abort(404) tasks.remove(task[0]) print(tasks) return jsonify({'result': True}) ##测试验证，更新一下2的状态： [root@localhost opt]# curl -i -H "Content-Type: application/json" -X PUT -d '{"done":true}' http://localhost:5000/todo/api/v1.0/tasks/2 HTTP/1.0 200 OK Content-Type: application/json Content-Length: 171 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:54:17 GMT { "task": [ { "description": "Need to find a good Python tutorial on the web", "done": true, "id": 2, "title": "Learn Python" } ] } ##删除task_2: [root@localhost opt]# curl -i -X DELETE http://localhost:5000/todo/api/v1.0/tasks/2 HTTP/1.0 200 OK Content-Type: application/json Content-Length: 21 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:58:31 GMT { "result": true } [root@localhost opt]# curl -i -X GET http://localhost:5000/todo/api/v1.0/tasks HTTP/1.0 200 OK Content-Type: application/json Content-Length: 163 Server: Werkzeug/0.15.6 Python/3.6.4 Date: Tue, 15 Oct 2019 15:58:49 GMT { "tasks": [ { "description": "Milk, Cheese, Pizza, Fruit, Tylenol", "done": false, "id": 1, "title": "Buy groceries" } ] }