爬虫代理 IP 池及隧道代理

日常开发中，偶尔会遇到爬取网页数据的需求，为了隐藏本机真实 IP，常常会用到代理 IP 池，本文将基于 openresty 与代理 IP 池搭建更为易用的隧道代理。

1. 代理 IP 池

1.1 简介

代理 IP 池即在数据库中维护一个可用的 IP 代理队列，一般实现思路如下：

1. 定时从免费或收费代理网站获取代理 IP 列表；
2. 将代理 IP 列表以 Hash 结构存入 Redis；
3. 定时检测代理 IP 的可用性，剔除不可用的代理 IP；
4. 对外提供 API 接口用来管理代理 IP 池；

1.2 实现

此处笔者采用的开源项目jhao104/proxy_pool，具体实现方式参考其文档。

1.3 测试

import json

import requests
from retrying import retry


def get_proxy_ip() -> str:
    resp = requests.get(url="http://192.168.0.121:5010/get")
    assert resp.status_code == 200
    return f"http://{json.loads(resp.text)['proxy']}"


@retry(stop_max_attempt_number=5)
def proxy_test() -> None:
    resp = requests.get(url="http://httpbin.org/get", proxies={"http": get_proxy_ip()}, timeout=5)
    assert resp.status_code == 200
    print(f"origin: {json.loads(resp.text)['origin']}")


if __name__ == "__main__":
    try:
        proxy_test()
    except Exception as e:
        print(f"Error: {e}.")

2. 隧道代理

2.1 简介

通过代理 IP 池实现了隐藏本机真实 IP，但每次需要通过 API 接口获取新的代理 IP，不太方便，所以出现了隧道代理。隧道代理内部自动将请求通过不同的代理 IP 进行转发，对外提供统一的代理地址。

2.2 实现

此处笔者通过 openresty 配合上文搭建的代理 IP 池实现隧道代理。

2.2.1 目录结构

openresty
├── conf.d
│   └── tunnel-proxy.stream
├── docker.sh
└── nginx.conf

2.2.2 配置文件

1. nginx.conf 文件为 openresty 的主配置文件，主要修改为引入了 stream 相关的配置文件，具体内容如下：

   # nginx.conf  --  docker-openresty
   #
   # This file is installed to:
   #   `/usr/local/openresty/nginx/conf/nginx.conf`
   # and is the file loaded by nginx at startup,
   # unless the user specifies otherwise.
   #
   # It tracks the upstream OpenResty's `nginx.conf`, but removes the `server`
   # section and adds this directive:
   #     `include /etc/nginx/conf.d/*.conf;`
   #
   # The `docker-openresty` file `nginx.vh.default.conf` is copied to
   # `/etc/nginx/conf.d/default.conf`.  It contains the `server section
   # of the upstream `nginx.conf`.
   #
   # See https://github.com/openresty/docker-openresty/blob/master/README.md#nginx-config-files
   #
   
   #user  nobody;
   #worker_processes 1;
   
   # Enables the use of JIT for regular expressions to speed-up their processing.
   pcre_jit on;
   
   
   
   #error_log  logs/error.log;
   #error_log  logs/error.log  notice;
   #error_log  logs/error.log  info;
   
   #pid        logs/nginx.pid;
   
   
   events {
       worker_connections  1024;
   }
   
   
   http {
       include       mime.types;
       default_type  application/octet-stream;
   
       # Enables or disables the use of underscores in client request header fields.
       # When the use of underscores is disabled, request header fields whose names contain underscores are marked as invalid and become subject to the ignore_invalid_headers directive.
       # underscores_in_headers off;
   
       #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
       #                  '$status $body_bytes_sent "$http_referer" '
       #                  '"$http_user_agent" "$http_x_forwarded_for"';
   
       #access_log  logs/access.log  main;
   
           # Log in JSON Format
           # log_format nginxlog_json escape=json '{ "timestamp": "$time_iso8601", '
           # '"remote_addr": "$remote_addr", '
           #  '"body_bytes_sent": $body_bytes_sent, '
           #  '"request_time": $request_time, '
           #  '"response_status": $status, '
           #  '"request": "$request", '
           #  '"request_method": "$request_method", '
           #  '"host": "$host",'
           #  '"upstream_addr": "$upstream_addr",'
           #  '"http_x_forwarded_for": "$http_x_forwarded_for",'
           #  '"http_referrer": "$http_referer", '
           #  '"http_user_agent": "$http_user_agent", '
           #  '"http_version": "$server_protocol", '
           #  '"nginx_access": true }';
           # access_log /dev/stdout nginxlog_json;
   
       # See Move default writable paths to a dedicated directory (#119)
       # https://github.com/openresty/docker-openresty/issues/119
       client_body_temp_path /var/run/openresty/nginx-client-body;
       proxy_temp_path       /var/run/openresty/nginx-proxy;
       fastcgi_temp_path     /var/run/openresty/nginx-fastcgi;
       uwsgi_temp_path       /var/run/openresty/nginx-uwsgi;
       scgi_temp_path        /var/run/openresty/nginx-scgi;
   
       sendfile        on;
       #tcp_nopush     on;
   
       #keepalive_timeout  0;
       keepalive_timeout  65;
   
       #gzip  on;
   
       include /etc/nginx/conf.d/*.conf;
   
       # Don't reveal OpenResty version to clients.
       # server_tokens off;
   }
   
   stream {
       log_format proxy '$remote_addr [$time_local] '
                        '$protocol $status $bytes_sent $bytes_received '
                        '$session_time "$upstream_addr" '
                        '"$upstream_bytes_sent" "$upstream_bytes_received" "$upstream_connect_time"';
       access_log /usr/local/openresty/nginx/logs/access.log proxy;
       error_log /usr/local/openresty/nginx/logs/error.log notice;
       open_log_file_cache off;
   
       include /etc/nginx/conf.d/*.stream;
   }
   

2. tunnel-proxy.stream 为配置隧道代理的文件，通过查询 Redis 获取代理 IP，并将请求通过代理 IP 转发到指定目标地址，具体内容如下：

   # tunnel-proxy.stream
   
   upstream backend {
       server 0.0.0.0:9870;
   
       balancer_by_lua_block {
           local balancer = require "ngx.balancer"
           local host = ngx.ctx.proxy_host
           local port = ngx.ctx.proxy_port
   
           local success, msg = balancer.set_current_peer(host, port)
           if not success then
               ngx.log(ngx.ERR, "Failed to set the peer. Error: ", msg, ".")
           end
       }
   }
   
   server {
       # 对外代理监听端口
       listen 9870;
       listen [::]:9870;
   
       proxy_connect_timeout 10s;
       proxy_timeout 10s;
       proxy_pass backend;
   
       preread_by_lua_block {
           local redis = require("resty.redis")
           local redis_instance = redis:new()
           redis_instance:set_timeout(3000)
   
           # Redis 地址
           local rhost = "192.168.0.121"
           # Redis 端口
           local rport = 6379
           # Redis 数据库
           local database = 0
           # Redis Hash 键名
           local rkey = "use_proxy"
           local success, msg = redis_instance:connect(rhost, rport)
           if not success then
               ngx.log(ngx.ERR, "Failed to connect to redis. Error: ", msg, ".")
           end
   
           redis_instance:select(database)
           local proxys, msg = redis_instance:hkeys(rkey)
           if not proxys then
               ngx.log(ngx.ERR, "Proxys num error. Error: ", msg, ".")
               return redis_instance:close()
           end
   
           math.randomseed(tostring(ngx.now()):reverse():sub(1, 6))
           local proxy = proxys[math.random(#proxys)]
           local colon_index = string.find(proxy, ":")
           local proxy_ip = string.sub(proxy, 1, colon_index - 1)
           local proxy_port = string.sub(proxy, colon_index + 1)
           ngx.log(ngx.NOTICE, "Proxy: ", proxy, ", ip: ", proxy_ip, ", port: ", proxy_port, ".");
           ngx.ctx.proxy_host = proxy_ip
           ngx.ctx.proxy_port = proxy_port
           redis_instance:close()
       }
   }
   

2.2.3 openresty

通过 docker 启动 openresty，此处笔者为了方便，将 docker 命令保存成了 shell 文件，具体内容如下：

docker run --name openresty -itd --restart always \
-p 9870:9870 \
-v $PWD/nginx.conf:/usr/local/openresty/nginx/conf/nginx.conf \
-v $PWD/conf.d:/etc/nginx/conf.d \
-e LANG=C.UTF-8 \
-e TZ=Asia/Shanghai \
--log-driver json-file \
--log-opt max-size=1g \
--log-opt max-file=3 \
openresty/openresty:alpine

执行 bash docker.sh 命名启动 openresty，至此隧道代理搭建完成。

2.3 测试

import json

import requests
from retrying import retry

proxies = {
    "http": "http://192.168.0.121:9870"
}


@retry(stop_max_attempt_number=5)
def proxy_test() -> None:
    resp = requests.get(
        url="http://httpbin.org/get", proxies=proxies,  timeout=5, )
    assert resp.status_code == 200
    print(f"origin: {json.loads(resp.text)['origin']}")


if __name__ == "__main__":
    try:
        proxy_test()
    except Exception as e:
        print(f"Error: {e}.")

参考链接：

• 只要5分钟，创建一个隧道代理 - 知乎 (zhihu.com)
• openresty正向代理搭建 - 简书 (jianshu.com)