Nginx+Lua实现动态黑名单

介绍

通过nginx+lua+redis可以实现nginx动态从redis读取需要拒绝的ip黑名单列表,并拒绝黑名单ip的访问请求。

其中redis中的ip黑名单列表既可以人工后台手动添加,也可以用类似logstash+elasticsearch的组合,实现logstash实时读取nginx的访问日志access.log,elasticsearch储存并聚合访问日志中的访问记录,再由一个分析程序定时统计分析访问记录后判断出要加入黑名单的ip,然后将ip储存到redis中的ip黑名单列表。

image

nginx配置

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http {
...
lua_shared_dict forbidden_list 5m;

location /lua {
# lua_code_cache off;
access_by_lua_file conf/lua/forbidden_list.lua;
default_type 'text/html';
content_by_lua 'ngx.say("hello world")';
}
}

lua配置

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local redis = require("resty.redis")
local ngx_log = ngx.log
local ngx_ERR = ngx.ERR
local ngx_INFO = ngx.INFO
local ngx_exit = ngx.exit
local ngx_var = ngx.var

-- 黑名单缓存60秒
local cache_idle = 60
local forbidden_list = ngx.shared.forbidden_list


local function close_redis(red)
if not red then
return
end
-- 释放连接(连接池实现)
local pool_max_idle_time = 10000 -- 毫秒
local pool_size = 100 -- 连接池大小
local ok, err = red:set_keepalive(pool_max_idle_time, pool_size)

if not ok then
ngx_log(ngx_ERR, "set redis keepalive error : ", err)
end
end

-- 从redis获取ip黑名单列表
local function get_forbidden_list()
local red = redis:new()
red:set_timeout(1000)
local ip = "127.0.0.1"
local port = 6379
local password = "password"
local ok, err = red:connect(ip, port)
if not ok then
ngx_log(ngx_ERR, "connect to redis error : ", err)
close_redis(red)
return
end

local res, err = red:auth(password)
if not res then
ngx_log(ngx_ERR, "failed to authenticate: ", err)
close_redis(red)
return
end

local resp, err = red:smembers("forbidden_list")
if not resp then
ngx_log(ngx_ERR, "get redis connect error : ", err)
close_redis(red)
return
end
-- 得到的数据为空处理
if resp == ngx.null then
resp = nil
end
close_redis(red)

return resp
end

-- 刷新黑名单
local function reflush_forbidden_list()
local current_time = ngx.now()
local last_update_time = forbidden_list:get("last_update_time");

if last_update_time == nil or last_update_time < (current_time - cache_idle) then
local new_forbidden_list = get_forbidden_list();
if not new_forbidden_list then
return
end

forbidden_list:flush_all()
for i, forbidden_ip in ipairs(new_forbidden_list) do
forbidden_list:set(forbidden_ip, true);
end
forbidden_list:set("last_update_time", current_time);
end
end


reflush_forbidden_list()
local ip = ngx_var.remote_addr
if forbidden_list:get(ip) then
ngx_log(ngx_INFO, "forbidden ip refused access : ", ip)
return ngx_exit(ngx.HTTP_FORBIDDEN)
end

redis修改黑名单

添加黑名单

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SADD forbidden_list "127.0.0.1"

移除黑名单

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SREM forbidden_list "127.0.0.1"

效果

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[root@localhost ~]# curl http://localhost/lua
<html>
<head><title>403 Forbidden</title></head>
<body bgcolor="white">
<center><h1>403 Forbidden</h1></center>
<hr><center>openresty/1.13.6.1</center>
</body>
</html>
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[root@localhost ~]# curl http://localhost/lua
hello world

日志

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2018/12/23 13:10:47 [info] 4416#0: *56 [lua] forbidden_list.lua:86: forbidden ip refused access : 127.0.0.1, client: 127.0.0.1, server: localhost, request: "GET /lua HTTP/1.1", host: "localhost"