在flask web中我们通常需要一个traceid作为调用参数传递给全链路各个调用函数
首先定义二个主要函数
import requests from flask import request, g import time from flask import Flask def get_uuid(): import uuid return str(uuid.uuid4()).replace('-', '') def trace_add_log_record(event_des='',msg_dict={},remarks=''): #trace_links_index每次调用+1 request.trace_links_index = request.trace_links_index + 1 logs = { 'traceid': g.traceid, 'trace_index': request.trace_links_index, 'event_des': event_des, 'msg_dict': msg_dict, 'remarks': remarks } print(logs) def trace_start_log_record_handler(): # 获取traceid,如果存在则使用，否则生成一个 if "traceid" in request.headers: g.traceid = request.headers['traceid'] else: g.traceid = get_uuid() # 初始化trace_links_index request.trace_links_index = 0 # 记录开始时间 request.start_time = time.time() log_msg = { 'headers': request.headers, 'url': request.url, 'method': request.method, "request_data": request.args if request.method == "GET" else request.get_json(), 'ip': request.headers.get("X-Real-IP") or request.remote_addr, 'start_time': request.start_time } # 记录日志 trace_add_log_record(event_des='start', msg_dict=log_msg) def trace_end_log_record_handler(reponse): # 记录结束时间 request.end_time = time.time() # 记录traceid到响应头 reponse.headers.add('traceid', g.traceid) log_msg = { "end_time" : request.end_time, "cost_time": request.end_time - request.start_time, "status_code": reponse.status_code, "headers": reponse.headers, "response_data": reponse.data.decode('utf-8') } # 记录日志 trace_add_log_record(event_des='end', msg_dict=log_msg)
接着，我们通过钩子函数去触发我们上述所写的两个重要函数
""" 写钩子函数在app中注册，还有一种写法 @app.before_request def before_request2(): print('before_request2') @app.after_request def after_request1(response): print('after_request1') return response """ #写钩子函数在app中注册 def register_handler(response): def before_request(): trace_start_log_record_handler() def after_request(response): trace_end_log_record_handler(reponse=response) return response # 注册钩子函数 response.before_request(before_request) response.after_request(after_request)
最后写测试接口进行测试
app = Flask(__name__) @app.route('/') def hello_world(): return 'Hello, World!' @app.route('/test') def test(): name = request.args.get('name') hello_world = requests.get('http://127.0.0.1:5000/', headers={'traceid': g.traceid}) return name + hello_world.text @app.route('/test2', methods=['POST']) def test2(): name = request.get_json().get('name') hello_world = requests.get('http://127.0.0.1:5000/', headers={'traceid': g.traceid}) return name + hello_world.text if __name__ == '__main__': register_handler(app) app.run(debug=True)
这样我们简单了完成了通过traceid把链路串联起来了
{'traceid': 'a5637579351c477a80090a88f5347088', 'trace_index': 1, 'event_des': 'start', 'msg_dict': {'headers': EnvironHeaders([('User-Agent', 'Apifox/1.0.0 (https://apifox.com)'), ('Content-Type', 'application/json'), ('Accept', '*/*'), ('Host', '127.0.0.1:5000'), ('Accept-Encoding', 'gzip, deflate, br'), ('Connection', 'keep-alive')]), 'url': 'http://127.0.0.1:5000/test?name=yetangjian', 'method': 'GET', 'request_data': ImmutableMultiDict([('name', 'yetangjian')]), 'ip': '127.0.0.1', 'start_time': 1717311086.757312}, 'remarks': ''}
{'traceid': 'a5637579351c477a80090a88f5347088', 'trace_index': 1, 'event_des': 'start', 'msg_dict': {'headers': EnvironHeaders([('Host', '127.0.0.1:5000'), ('User-Agent', 'python-requests/2.25.1'), ('Accept-Encoding', 'gzip, deflate'), ('Accept', '*/*'), ('Connection', 'keep-alive'), ('Traceid', 'a5637579351c477a80090a88f5347088')]), 'url': 'http://127.0.0.1:5000/', 'method': 'GET', 'request_data': ImmutableMultiDict([]), 'ip': '127.0.0.1', 'start_time': 1717311086.7663064}, 'remarks': ''}
{'traceid': 'a5637579351c477a80090a88f5347088', 'trace_index': 2, 'event_des': 'end', 'msg_dict': {'end_time': 1717311086.7663064, 'cost_time': 0.0, 'status_code': 200, 'headers': Headers([('Content-Type', 'text/html; charset=utf-8'), ('Content-Length', '13'), ('traceid', 'a5637579351c477a80090a88f5347088')]), 'response_data': 'Hello, World!'}, 'remarks': ''}
{'traceid': 'a5637579351c477a80090a88f5347088', 'trace_index': 2, 'event_des': 'end', 'msg_dict': {'end_time': 1717311086.7683115, 'cost_time': 0.010999441146850586, 'status_code': 200, 'headers': Headers([('Content-Type', 'text/html; charset=utf-8'), ('Content-Length', '23'), ('traceid', 'a5637579351c477a80090a88f5347088')]), 'response_data': 'yetangjianHello, World!'}, 'remarks': ''}