Nginx 使用Lua脚本

安装 Nginx Lua支持

1. 安装系统依赖库

        yum install readline-devel pcre-devel openssl-devel gcc

    

2. 安装LuaJIT

        $ wget http://luajit.org/download/LuaJIT-2.0.5.tar.gz
$ tar zxvf LuaJIT-2.0.5.tar.gz
$ cd LuaJIT-2.0.5
$ make install
# 安装成功
==== Successfully installed LuaJIT 2.0.5 to /usr/local ====

    

3. 设置LuaJIT环境变量

        $ export LUAJIT_LIB=/usr/local/lib
$ export LUAJIT_INC=/usr/local/include/luajit-2.0
$ echo "/usr/local/lib" > /etc/ld.so.conf.d/usr_local_lib.conf
$ ldconfig

    

4. 下载相关模块

ngx_devel_kit

        $ wget https://github.com/simpl/ngx_devel_kit/archive/v0.3.0.tar.gz
$ tar zxvf v0.3.0.tar.gz
# 解压缩后目录名
ngx_devel_kit-0.3.0

    

lua-nginx-module

        $ wget https://github.com/openresty/lua-nginx-module/archive/v0.10.10.tar.gz
$ tar zxvf v0.10.10.tar.gz
# 解压缩后目录名
lua-nginx-module-0.10.10

    

5. 重新编译Nginx模块

        # 最好先查看下之前编译的
./sbin/nginx -V

./configure --prefix=/home/ifan/software/nginx     --with-http_ssl_module     --with-http_v2_module     --with-http_stub_status_module     --with-http_realip_module     --with-threads     --with-http_realip_module     --add-module=/home/ifan/lua-nginx-module-0.10.10     --add-module=/home/ifan/ngx_devel_kit-0.3.0

make && make install

    

6. 配置Nginx环境

6.1 添加 Http lua 支持

        http {
    # 第三方库（cjson）地址luajit-2.0/lib
    lua_package_path ‘./lua/?.lua;;‘;
    lua_package_cpath ‘/usr/local/include/luajit-2.0/lib/?.so;;‘;
}

    

6.2 添加一个Lua服务

        server {
    location /ip {
        # 正式环境需要去掉，现在加上方便调试lua脚本
		lua_code_cache off;
		default_type ‘text/plain‘;

        # nginx下的相对路径
        content_by_lua_file lua/get_ip.lua;

		# content_by_lua ‘ngx.say("hello, lua")‘;

		# content_by_lua_block {
		#     ngx.say("hello lua")
		# }
    }
}

    

6.3 添加nginx/lua/get_ip.lua

        local headers = ngx.req.get_headers()

for k, v in pairs(headers) do
	ngx.say(k,":", v)
end

ngx.say("X-REAL-IP", ":", headers["X-REAL-IP"])
ngx.say("X_FORWARDED_FOR", ":", headers["X_FORWARDED_FOR"])
ngx.say("remote_addr", ":", ngx.var.remote_addr)

    

一些配置信息

lua常用系统变量

模块指令

每个模块都有*_lua(指令)、*_lua_block(代码块)、*_lua_file(脚本文件)

案例

访问权限控制

        location / {
    set $allowed ‘115.171.226.212‘;
    access_by_lua_block {
        if ngx.re.match(ngx.req.get_method(), "PUT|POST|DELETE") and not ngx.re.match(ngx.var.request_uri, "_search") then
			start, _ = string.find(ngx.var.allowed, ngx.var.remote_addr)
			if not start then
				ngx.exit(403)
			end
		end
    }
	
    proxy_pass http://127.0.0.1:8000$request_uri;
}

    

访问频率控制

在 Nginx 配置文件的 location 部分配置 Lua 脚本基本参数，并配置 Lua 模块指令：

        default_type "text/html";
set rate_per 300
access_by_lua_file lua/access.lua;

    

Lua 脚本实现频率控制逻辑，使用 Redis 对单位时间内的访问次数做缓存，key 为访问 uri 拼接 token 后的 md5 值。具体内容如下：

        local redis = require "resty.redis"
local red = redis:new()

local limit = tonumber(ngx.var.rate_per) or 200
local expire_time = tonumber(ngx.var.rate_expire) or 1000
local key = "rate.limit:string:"

red:set_timeout(500)
local ok, err = red:connect("www.fanhaobai.com", 6379)
if not ok then
    ngx.log(ngx.ERR, "failed to connect redis: " .. err)
    return
end

key = key .. ngx.md5(ngx.var.request_uri .. (ngx.req.get_uri_args()[‘token‘] or ngx.req.get_post_args()[‘token‘]))
local times, err = red:incr(key)
if not times then
    ngx.log(ngx.ERR, "failed to exec incr: " .. err)
    return
elseif times == 1 then
    ok, err = red:expire(key, expire_time)
    if not ok then
        ngx.log(ngx.ERR, "failed to exec expire: " .. err)
        return
    end
end

if times > limit then
    return ngx.exit(403)
end

return

    

原文：https://www.cnblogs.com/iFanLiwei/p/13574968.html