nginx ip黑名单动态封禁

网站被恶意请求，拉黑IP是重要的手段，如果每次拉黑都要到nginx上配置，未免太low了；我们需要更方便的控制nginx IP黑名单。

1.方案

黑名单持久化到mysql （常见的方案是redis，但不利于控制，如：不同的IP设置不同的有效期、IP的CRUD、统计等等）；

通过lua-nginx-module，在nginx中开辟一块内存（lua_shared_dict），lua将黑名单定期从mysql全量刷新至lua_shared_dict；

所有请求，都要到与lua_shared_dict中的IP check一下。

2.安装

2.1 安装luajit

cd LuaJIT-2.0.5
make
make install PREFIX=/usr/local/luajit

2.2.安装nginx时，将lua模块编译进去

export LUAJIT_LIB=/usr/local/luajit/lib
export LUAJIT_INC=/usr/local/luajit/include/luajit-2.1

./configure --prefix=/nginx \
--with-ld-opt="-Wl,-rpath,/usr/local/luajit/lib" \
--add-module=/opt/ngx_devel_kit-0.3.1rc1 \
--add-module=/opt/lua-nginx-module-0.10.14rc3

make -j2
make install
ln -s /nginx/sbin/nginx /usr/sbin/nginx

3.配置

3.1 nginx配置

http {
      server_tokens  off;
      lua_package_path "/usr/local/lib/lua/?.lua;;";
      lua_shared_dict ip_blacklist 4m;
}

server {
        set $real_ip $remote_addr;
        if ( $http_x_forwarded_for ~ "^(\d+\.\d+\.\d+\.\d+)" ) {
                set $real_ip $1;
        }

        # 管理信息，访问该URL可以查看nginx中的IP黑名单信息
        location /get-ipblacklist-info {
                access_by_lua_file conf/lua/get_ipblacklist_info.lua;
        }
 
        # 同步URL，通过定时任务调用该URL,实现IP黑名单从mysql到nginx的定时刷新
        location /sync-ipblacklist {
            access_by_lua_file conf/lua/sync_ipblacklist.lua;
        }

        # 生产域名配置，所有需要IP黑名单控制的location，都要包含以下语句
        location / {
            access_by_lua_file conf/lua/check_realip.lua;
        }

}

nginx服务器配置以下crrontab

* * * * * /usr/bin/curl -o /dev/null -s http://127.0.0.1/sync-ipblacklist > /dev/null 2>&1

3.2 lua脚本

sync_ipblacklist.lua

local mysql_host = "ip of mysql server"
local mysql_port = 3306
local database   = "dbname"
local username   = "user"
local password   = "password"

-- update ip_blacklist from mysql once every cache_ttl seconds
local cache_ttl     = 1
local mysql_connection_timeout = 1000

local client_ip        = ngx.var.real_ip
local ip_blacklist     = ngx.shared.ip_blacklist
local last_update_time = ip_blacklist:get("last_update_time");

if last_update_time == nil or last_update_time < ( ngx.now() - cache_ttl ) then

  local mysql = require "resty.mysql";
  local red = mysql:new();

  red:set_timeout(mysql_connect_timeout);
  
  local ok, err, errcode, sqlstate = red:connect{
                    host = mysql_host,
                    port = mysql_port,
                    database = database,
                    user = username,
                    password = password,
                    charset = "utf8",
                    max_packet_size = 1024 * 1024,
                }
  if not ok then
    ngx.log(ngx.ERR, "mysql connection error while retrieving ip_blacklist: " .. err);
  else
    new_ip_blacklist, err, errcode, sqlstate = red:query("select ip_addr from ip_blacklist where status = 0 order by create_time desc limit 10000", 100)
    if not new_ip_blacklist then
      ngx.log(ngx.ERR, "bad result. errcode: " .. errcode .. " sqlstate: " .. sqlstate .. " err: " .. err);
      return
    end

    ip_blacklist:flush_all();
    for k1, v1 in pairs(new_ip_blacklist) do
      for k2, v2 in pairs(v1) do
        ip_blacklist:set(v2,true);
      end
    end

    ip_blacklist:set("last_update_time", ngx.now());
  end
end

ngx.say("sync successful");

get_ipblacklist_info.lua

-- 调用URL查看黑名单信息
-- 1万IP消耗不到1.5M ngx.shared内存
-- 获取所有KEY会堵塞别的正常请求对ngx.shared内存的访问，因此只能取少数key展示
require "resty.core.shdict"
ngx.say("total space: " .. ngx.shared.ip_blacklist:capacity() .. "<br/>");
ngx.say("free space: " .. ngx.shared.ip_blacklist:free_space() .. "<br/>");
ngx.say("last update time: " .. os.date("%Y%m%d_%H:%M:%S",ngx.shared.ip_blacklist:get("last_update_time")) .. "<br/>");
ngx.say("first 100 keys: <br/>");
ngx.say("--------------------------<br/>");
ip_blacklist = ngx.shared.ip_blacklist:get_keys(100);
for key, value in pairs(ip_blacklist) do
    ngx.say(key .. ": " .. value .. "<br/>");
end

check_realip.lua

if ngx.shared.ip_blacklist:get(ngx.var.real_ip) then
    return ngx.exit(ngx.HTTP_FORBIDDEN);
end

3.3 数据库设计

CREATE TABLE `ip_blacklist` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `ip_addr` varchar(15) COLLATE utf8mb4_bin DEFAULT NULL,
  `status` int(11) DEFAULT '0' COMMENT '0: valid 有效, 1: invalid 失效',
  `effective_hour` decimal(11,2) DEFAULT '24' COMMENT '有效期，单位：小时',
  `ip_source` varchar(255) COLLATE utf8mb4_bin DEFAULT NULL COMMENT '黑名单来源',
  `create_time` datetime DEFAULT CURRENT_TIMESTAMP,
  `modify_time` datetime DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `remark` varchar(255) COLLATE utf8mb4_bin DEFAULT NULL COMMENT '备注',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;


CREATE PROCEDURE proc_ip_blacklist_status_update()
-- 将过期的IP状态改为失效
begin 
    update ip_blacklist
    set status=1
    where date_add(create_time,INTERVAL effective_hour hour) < now();
    commit;
end;


CREATE EVENT job_ip_blacklist_status_update
ON SCHEDULE EVERY 1 MINUTE
ON COMPLETION PRESERVE
ENABLE
DO
call proc_ip_blacklist_status_update();