摘要：Flask，logging

设置日志处理器

在__init__.py中注册日志对象，使用app.logger设置日志等级和增加处理器，设置处理器为按照日期切分，最大保留30天。

import os
import logging
from logging.handlers import RotatingFileHandler

from settings import config


def create_app(config_name=None):
    if config_name is None:
        config_name = os.getenv('FLASK_CONFIG', 'development')
    app = Flask('pira_score_web')
    app.config.from_object(config[config_name])

    def register_logging(app):
        app.logger.setLevel(logging.INFO)
        formatter = logging.Formatter('%(asctime)s [%(module)s] %(levelname)s %(message)s', '%Y-%m-%d %H:%M:%S')
        time_rotating_handler = TimedRotatingFileHandler('logs/detail.log', when='d', interval=1, backupCount=30,
                                                         encoding="utf8", delay=False)
        time_rotating_handler.setLevel(logging.INFO)
        time_rotating_handler.setFormatter(formatter)
        app.logger.addHandler(time_rotating_handler)

    register_logging(app)

    return app

设置日志格式和生成request_id

为日志生成一个随机ID，同一个请求设计多个服务调用标识为同一个ID，使用uuid模块调用uuid.uuid4().hex自动生成32位随机ID，存储在钩子函数before_request的g对象中，请求结束在after_request获取从一次请求的g对象中获取request_id，所有日志字段如下：

• status_code：状态码response.status_code
• method：请求方法request.method
• ip：请求头request.headers中有X-Real-IP就用，没有用request.remote_addr
• url：请求的url路径request.url
• Referer：从请求头request.headers中获取来源页面
• agent：从请求头request.headers中获取User-Agent用户代理
• requestId：获取请求的request_id

import uuid

from flask import Flask, g, request

def create_app(config_name=None):
    app = Flask('pira_score_web')
    ...
    ...
    ...
    @app.before_request
    def before_request():
        g.requestId = uuid.uuid4().hex

    @app.after_request
    def after_request(response):
        app.logger.info(json.dumps({
            "AccessLog": {
                "status_code": response.status_code,
                "method": request.method,
                "ip": request.headers.get('X-Real-IP', request.remote_addr),
                "url": request.url,
                # "referer": request.headers.get('Referer'),
                # "agent": request.headers.get("User-Agent"),
                "requestId": str(g.requestId),
            }
        }, ensure_ascii=False
        ))
        return response
    return app

在蓝图中调用

在主程序中已经设置了每次请求结束写入磁盘日志，在蓝图中使用current_app.logger调用日志对象将报错信息输入日志文件

from flask import Blueprint, render_template, current_app, abort

index = Blueprint('index', __name__)


@index.route('/index', methods=['GET'])
def index_info():
    try:
        a = 1
    except Exception as e:
        current_app.logger.error(e)
        abort(404)
    return render_template('index.html', **locals())