自动更新host实现github加速

如题，当前github的dns已经被污染，在不同cdn加持下，经常会抽风，虽然已经被微软收购，目前的整治可能还需一段时间，目前主流的优化方法无非也就几种，考虑安全风险问题，所以不推荐使用镜像加速，当然修改dns也有安全隐患，这个仁者见仁智者见智吧，分享一个自动修改host实现github加速的脚本。

原理简介

1. 首先查询github在当前网路最佳的访问节点（存在安全隐患，如果不信任站长工具给的IP可以换成其他源，只要给的节点能够有效加速）
   
2. 拷贝IP，打开系统host文件，单机修改时如此，如果在自己的局域网修改，则需要在dns服务器上设置，因为过期时间较短，建议制作成定时任务的形式更新（以下是我目前的host）。

185.199.110.153 assets-cdn.Github.com
#140.82.114.4 github.com
#52.192.72.89 github.com
# ipconfig /flushdns
#20.205.243.166 github.com
199.232.69.194 github.global.ssl.fastly.net
185.199.109.133 raw.githubusercontent.com
13.114.40.48 github.com
#52.69.186.44 github.com

源码

# coding=utf-8
"""

查询访问github最佳的女生路线并配置到电脑host文件中

dns来源：站长工具
"""
import json
import logging
import os
import platform

try:
    # noinspection PyCompatibility
    from urllib.request import urlopen, Request
    # noinspection PyCompatibility
    from urllib.error import HTTPError, URLError
except ImportError:
    # noinspection PyUnresolvedReferences,PyCompatibility
    from urllib2 import urlopen, Request, HTTPError, URLError

logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')
logger = logging.getLogger(__name__)

host_window = r"C:\Windows\System32\drivers\etc\hosts"
host_unix = r"/etc/hosts"


def get_best_ip(host):
    """查询dns github最佳解析路线, 默认是github"""
    # noinspection HttpUrlsUsage
    api = "http://tool.chinaz.com/AjaxSeo.aspx?t=dns&server=JACYvxRvL1|CnyK9sCL7~g=="
    headers = {'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8', }
    data = 'host={host}&type=1&total=10&process=6&right=3'.format(host=host)
    req = Request(api, data=data.encode(), headers=headers)
    try:
        res = urlopen(req).read().decode('utf-8')
        res_json = json.loads(res[1: -1])
        return (res_json.get('list') or [{}])[0].get('result', '')
    except (HTTPError, URLError):
        logger.exception("网络连接异常")
    except json.decoder.JSONDecodeError:
        logger.exception("解析错误")
    except UnicodeDecodeError:
        logger.exception("解码错误")
    except Exception as e:
        logger.exception("未知错误 {}".format(e))
    return ''


def _get_path():
    """获取host路径"""
    if platform.system() is "Windows":
        return host_window
    return host_unix


def read_host():
    """读取host"""
    with open(_get_path(), 'r', encoding='utf-8') as f:
        return f.read()


def write_host(text):
    """写入host"""
    with open(_get_path(), 'w+', encoding='utf-8') as f:
        return f.write(text)


def set_host(host='github.com'):
    """设置host文件"""
    host_text = read_host()
    logger.info('读取host \n{}'.format(host_text))
    host_list = [[keyword.strip() for keyword in line.split() if keyword] for line in host_text.split('\n') if
                 line and len(line.split()) >= 2]
    best_ip = get_best_ip(host)
    if not best_ip:
        logger.warning('查询到ip数据为空')
        return
    reset = False
    for line in host_list:
        # 如果是在使用的IP不与最佳ip相同则进行注释
        if line[1] == host:
            if not line[0].startswith('#'):
                line[0] = "#" + line[0]
            if line[0] == "#" + best_ip:
                line[0] = line[0].strip("#")
                reset = True
    if not reset:
        host_list.append([best_ip, host])
    host_text = '\n'.join([' '.join(line) for line in host_list])
    logger.info('修改host \n{}'.format(host_text))
    write_host(host_text)
    if platform.system() == 'Windows':
        os.system('ipconfig /flushdns')
    logger.info('设置成功， 当前 {} 的解析IP为 {}'.format(host, best_ip))


if __name__ == '__main__':
    set_host()