ngx_lua 随笔
--[[
test
--]]
ngx.header.content_type = "text/plain"; --输出头部
local user = ngx.var.arg_user -- 定义user变量并获取url中的参数 http://localhost?user=hello
local sys = ngx.var.server_name -- 获取nginx中的变量
ngx.say (user); -- 输出至页面
ngx.say (sys);
if user== "spam" then
local res=ngx.location.capture("/lua") -- capture
if res.status == 200 then
ngx.print("capture:",res.body)
end
end
tbl = {"alpha", "beta", "gamma"} --定义table 数组
table.insert(tbl, "delta") --增加数组元素
table.sort( tbl, sortLevelNameAsc ) -- 数组排序
for i = 1, table.getn(tbl) do -- for循环
ngx.say(string.format("%s", tbl[i])) -- string format
end
local deled=table.remove(tbl, 2) -- 删除指定位置元素并返回删除元素.如果没有指定删除的位置,则默认删除table的最后一个元素
ngx.say ("delete the second element " .. deled ) -- 字符串连接 ..
gTable = {}
gTable.name = "eric"
gTable.gender = "man"
gTable.phonenumber = "0000000000"
gTable[1] = "公司"
gTable[2] = "部门"
gTable.hobby = {"跑步", "读书", "游戏", "动漫"} -- 多维table,可以通过gTable.hobby[1]的方式访问.即gTable.hobby本身也是一个table
gTable.secTable = {}
gTable.secTable.job = "程序员"
gTable.secTable.label = "写代码的"
gTable.secTable.description = "职责是实现产品的逻辑"
for index, value in pairs(gTable) do
ngx.say(string.format("%s:%s", index, value)) -- string format
if ("table" == type(value)) then
for idx, var in pairs(value) do
ngx.say(string.format("二维table:%s:%s", idx, var)) -- string format
end
end
end
--[[
输出结果如下:
1 公司
2 部门
hobby table: 0x7fdceac14bc0
二维table: 1 跑步
二维table: 2 读书
二维table: 3 游戏
二维table: 4 动漫
phonenumber 0000000000
gender man
secTable table: 0x7fdceac15100
二维table: label 写代码的
二维table: description 职责是实现产品的逻辑
二维table: job 程序员
name eric
--]]
ngx.say (table.concat( tbl, ":")) -- join
ngx.say(#tbl) -- 返回数组个数
ngx.say(os.time()) -- 1423643892
ngx.say(os.date()) -- Wed Feb 11 16:38:12 2015
ngx.say(os.date("%m/%d/%Y",os.time())) -- 02/11/2015
ngx.say(os.date("%Y-%m-%d %H:%M:%S",1423643892)) -- 2015-02-11 16:38:12 time to date
ngx.say(os.time{year="2015", month="2", day="11", hour="16",min="38",sec="12"}) -- 1423643892 date to time
ngx.say(tonumber("100")+11) --字符与数字的显式转换 输出结果为:111
ngx.say(type(tostring(100))) --转换成字符串 并获取类型 输出结果为:string
ngx.say(string.len("hello")) --字符串长度 输出结果为:5
ngx.say(string.sub("hello Lua", 7,9)) --截取字符串 输出结果为:Lua
ngx.say(math.random(1,2)); --随机数
ngx.print(ngx.req.raw_header(),ngx.var.uri) -- 获取http header 信息
--[[
获取ip
--]]
local function getip( )
local myIP = ngx.req.get_headers()["X-Real-IP"]
if myIP == nil then
myIP = ngx.req.get_headers()["x_forwarded_for"]
end
if myIP == nil then
myIP = ngx.var.remote_addr
end
return myIP
end
ngx.print(getip()) --调取函数 按顺序,必须先申明方法 才能调用
ngx.redirect("http://www.elong.com") --跳转
多行字符串
local longstring=[[123 456 abc 'szSuffix' ]] ngx.say(longstring)
ngx_lua安装
ngx_lua安装可以通过下载模块源码,编译Nginx,但是推荐采用openresty。Openresty就是一个打包程序,包含大量的第三方Nginx模块,比如HttpLuaModule,HttpRedis2Module,HttpEchoModule等。省去下载模块,并且安装非常方便。
ngx_openresty bundle: openresty
./configure --with-luajit&& make && make install
默认Openresty中ngx_lua模块采用的是标准的Lua5.1解释器,通过--with-luajit使用LuaJIT。
ngx.location.capture
location = /other { ehco 'Hello, world!'; } # Lua非阻塞IO location = /lua { content_by_lua ' local res = ngx.location.capture("/other?id=12") if res.status == 200 then ngx.print(res.body) end '; }
capture post
-- POST https://www.example.com:443/foo/bar?hello=world
ngx.req.set_header("Content-Type", "application/json;charset=utf8"); ngx.req.set_header("Accept", "application/json"); local res = ngx.location.capture('/proxy/https/www.example.com/443/foo/bar', { method = ngx.HTTP_POST, body = body, args = {hello = 'world'} });
ngx.location.capture_multi
语法:res1,res2, ... = ngx.location.capture_multi({ {uri, options?}, {uri, options?}, ...})
与ngx.location.capture功能一样,可以并行的、非阻塞的发出多个子请求。这个方法在所有子请求处理完成后返回,并且整个方法的运行时间取决于运行时间最长的子请求,并不是所有子请求的运行时间之和。
# 同时发送多个子请求(subrequest) location = /moon { ehco 'moon'; } location = /earth { ehco 'earth'; } location = /lua { content_by_lua ' local res1,res2 = ngx.location.capture_multi({ {"/moon"}, {"earth"} }) if res1.status == 200 then ngx.print(res1.body) end ngx.print(",") if res2.status == 200 then ngx.print(res2.body) end '; }
set_by_lua
和set指令一样用于设置Nginx变量并且在rewrite阶段执行,只不过这个变量是由lua脚本计算并返回的。
语法:set_by_lua$res <lua-script-str> [$arg1 $arg2 ...]
location = /adder { set_by_lua $res " local a = tonumber(ngx.arg[1]) local b = tonumber(ngx.arg[2]) return a + b" $arg_a $arg_b; echo $res; }
set_by_lua_file
执行Nginx外部的lua脚本,可以避免在配置文件中使用大量的转义
location = /fib { set_by_lua_file $res "conf/adder.lua" $arg_n; echo $res; }
adder.lua:
local a = tonumber(ngx.arg[1])
local b = tonumber(ngx.arg[2])
return a + b
access_by_lua和access_by_lua_file
运行在access阶段,用于访问控制。Nginx原生的allow和deny是基于ip的,通过access_by_lua能完成复杂的访问控制,比如,访问数据库进行用户名、密码验证等。
location /auth { access_by_lua ' if ngx.var.arg_user == "ntes" then return else Ngx.exit(ngx.HTTP_FORBIDDEN) end '; echo 'welcome ntes'; }
输出:
$ curl 'localhost/auth?user=sohu' $ Welcome ntes $ curl 'localhost/auth?user=ntes' $ <html> <head><title>403 Forbidden</title></heda> <body bgcolor="white"> <center><h1>403 Forbidden</h1></center> <hr><center>ngx_openresty/1.0.10.48</center> </body> </html>
rewrite_by_lua和rewrite_by_lua_file
实现url重写,在rewrite阶段执行。
配置:
location = /foo { rewrite_by_lua 'ngx.exec("/bar")'; echo 'in foo'; } location = /bar { echo 'Hello, Lua!'; }
输出:
$ curl 'localhost/lua' $ Hello, Lua!
content_by_lua和content_by_lua_file
Contenthandler在content阶段执行,生成http响应。由于content阶段只能有一个handler,所以在与echo模块使用时,不能同时生效,我测试的结果是content_by_lua会覆盖echo。这和之前的hello world的例子是类似的。
location = /lua { content_by_lua 'ngx.say("Hello, Lua!")'; }
os.execute ([command])
功能:相当于C的system函数,返回系统状态码
例如:
os.execute("pause")
输出:
按任意键继续. . .
os.exit ([code])
功能:相当于C的exit函数,终止主程序,code为返回值
例如:
os.exit(1)
os.getenv (varname)
例如:
print(os.getenv("USERDOMAIN")) print(os.getenv("SystemRoot")) print(os.getenv("Os2LibPath")) print(os.getenv("ProgramFiles" )) print(os.getenv("APPDATA" )) print(os.getenv("ALLUSERSPROFILE" )) print(os.getenv("CommonProgramFiles" )) print(os.getenv("COMPUTERNAME" )) print(os.getenv("USERNAME")) print(os.getenv("USERPROFILE" )) print(os.getenv("ComSpec")) print(os.getenv("LOGONSERVER" )) print(os.getenv("NUMBER_OF_PROCESSORS" )) print(os.getenv("OS")) print(os.getenv("PATHEXT" )) print(os.getenv("PROCESSOR_ARCHITECTURE" )) print(os.getenv("PROCESSOR_IDENTIFIER" )) print(os.getenv("PROCESSOR_LEVEL" )) print(os.getenv("PROCESSOR_REVISION" )) print(os.getenv("USERDOMAIN")) print(os.getenv("SystemRoot" )) print(os.getenv("TEMP"))
输出:
RDEV C:\WINDOWS nil C:\Program Files C:\Documents and Settings\baiyun\Application Data C:\Documents and Settings\All Users C:\Program Files\Common Files BAIYUN baiyun C:\Documents and Settings\baiyun C:\WINDOWS\system32\cmd.exe http://www.cnblogs.com/whiteyun/admin/file://rdev1/ 2 Windows_NT .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.py;.pyw;.wlua x86 x86 Family 15 Model 6 Stepping 5, GenuineIntel 15 0605 RDEV C:\WINDOWS C:\DOCUME~1\baiyun\LOCALS~1\Temp
os.remove (filename)
功能:删除文件或一个空目录,若函数调用失败则返加nil加错误信息
os.rename (oldname, newname)
功能:更改一个文件或目录名,若函数调用失败则返加nil加错误信息
调取 mysql json redis操作
ngx.say("=============== mysql ==============") local mysql = require "resty.mysql" local db,err = mysql:new() if not db then ngx.say("failed to instantiate mysql: ",err) return end db:set_timeout(1000) local ok,err,errno,sqlstate = db:connect{ host = "127.0.0.1", port = 3306, database = "el_agency", user = "root", password = "", max_package_size = 1024 } if not ok then ngx.say("failed to connect: ", err, ": ", errno, " ", sqlstate) return end
db:query("set names utf8") ngx.say("connected to mysql.") res,err,errno,sqlstate = db:query("select username,appKey,secretKey from tbl_user limit 2") if not res then ngx.say("bad result: ", err, ": ", errno, ": ", sqlstate, ".") return end
db:close()
ngx.say("=============== cjson ==============") local cjson = require "cjson"; local res1=cjson.encode(res); ngx.say(res1); local res2=cjson.decode(res1); print_lua_table(res2); ngx.say("=============== redis ==============") local redis = require("resty.redis") local client = redis:new() client:set_timeout(1000) -- 1 second local ok,err = client:connect("127.0.0.1",6379) if not ok then ngx.say("failed to connect: ",err) return end client:set("hello","world"); local res,err = client:get("hello") if not res then ngx.say("failed to get",err) return end
client:close()
ngx.say(res)
执行顺序
1.init_by_lua 上下文http ngx启动时执行 2.set_by_lua 上下文 server, server if, location, location if 3.rewrite_by_lua 上下文 http, server, location, location if 4.access_by_lua 上下文 http, server, location, location if 5.content_by_lua 上下文 location, location if 6.header_filter_by_lua 上下文 http, server, location, location if 7.body_filter_by_lua 上下文 http, server, location, location if 8.log_by_lua 上下文 http, server, location, location if
lua中 三目运算符的实现
(a and b) or c <==> a ? b : c
lua urlencode urldecode URL编码
function decodeURI(s) s = string.gsub(s, '%%(%x%x)', function(h) return string.char(tonumber(h, 16)) end) return s end function encodeURI(s) s = string.gsub(s, "([^%w%.%- ])", function(c) return string.format("%%%02X", string.byte(c)) end) return string.gsub(s, " ", "+") end
或者
ngx.escape_uri() 字符串的url编码
ngx.unescape_uri() 字符串url解码
LUA require 搜索路径指定方法
如果是一个 *.LUA 的文件, 里面用到了自己写的库, 或者第三方写的库, 但是你不想把它放到 lua 的安装目录里, 则在代码里面可以指定require搜索的路径。 package.path = '/usr/local/share/lua/5.1/?.lua;/home/resty/?.lua;;' --搜索lua模块 ;;指定默认路径 package.cpath = '/usr/local/lib/lua/5.1/?.so;;' --搜索so模块 如果是要在 nginx.conf 文件中引用第三方的库,则需要在 http 段中添加下面的代码 lua_package_path '/usr/local/share/lua/5.1/?.lua;/home/resty/?.lua;'; lua_package_cpath '/usr/local/lib/lua/5.1/?.so;';
lua下面dump出一个table的结构
--- @brief 调试时打印变量的值 --- @param data 要打印的字符串 --- @param [max_level] table要展开打印的计数,默认nil表示全部展开 --- @param [prefix] 用于在递归时传递缩进,该参数不供用户使用于 --- @ref http://dearymz.blog.163.com/blog/static/205657420089251655186/ function var_dump(data, max_level, prefix) if type(prefix) ~= "string" then prefix = "" end if type(data) ~= "table" then print(prefix .. tostring(data)) else print(data) if max_level ~= 0 then local prefix_next = prefix .. " " print(prefix .. "{") for k,v in pairs(data) do io.stdout:write(prefix_next .. k .. " = ") if type(v) ~= "table" or (type(max_level) == "number" and max_level <= 1) then print(v) else if max_level == nil then var_dump(v, nil, prefix_next) else var_dump(v, max_level - 1, prefix_next) end end end print(prefix .. "}") end end end
ngx.exec
location @cc { internal; root html; index index.html index.htm; } 代码中 ngx.exec("@cc")
iptolong
-- 参数:待分割的字符串,分割字符 -- 返回:子串表.(含有空串) function split(s, delim) if type(delim) ~= "string" or string.len(delim) <= 0 then return end local start = 1 local t = {} while true do local pos = string.find (s, delim, start, true) -- plain find if not pos then break end table.insert (t, string.sub (s, start, pos - 1)) start = pos + string.len (delim) end table.insert (t, string.sub (s, start)) return t end --ip转整数 function ip2long(ip) local ips=split(ip,".") local num = 0 for i,v in pairs(ips) do num =num +(tonumber(v) * math.pow(256,#ips-i)) end return num end
获取当前路径及上级目录
function dirname(str) if str:match(".-/.-") then local name = string.gsub(str, "(.*/)(.+)", "%1") return name elseif str:match(".-\\.-") then local name = string.gsub(str, "(.*\\)(.+)", "%1") return name else return '' end end local __FILE__ = debug.getinfo(1,'S').source:sub(2) ROOT_PATH=dirname(__FILE__)
lua 创建一个“类” 并返回“类”中的所有方法
--helper.lua local _M = { _VERSION = '0.09' } function _M.to_hex(s) end function _M.atoi (s) end return _M local helper=require 'helper' var_dump(helper) 返回 ["to_hex"] = function: 0x0cd26038, ["atoi"] = function: 0x0cd260e8, ["_VERSION"] = "0.09",
package.seeall
--game.lua module(..., package.seeall) --- ...不定参数 function play() return "ok just do it"end function quit() return "welcome back again"end
--require local game=require 'game' ngx.say(game:play())
Nginx中Lua模块的运行机制
Nginx中的每个Worker进程使用一个lua虚拟机,工作进程中的所有协程共享虚拟机。将Nginx中的lua API封装好之后注入到lua的VM中就可以在lua代码中进行访问
异常捕获pcall
local user = ngx.var.arg_user local st,err=pcall(function()
if user == "spam" then local res=ngx.location.capture("/lua") -- capture if res.status == 200 then ngx.print("capture:",res.body) end else error("出错啦") end
end); if not st then ngx.say(err) end
----类似于php
try{
if (user == "spam"){
//todo
}else{
throw New Exception("出错啦")
}
}catch(Exception $ex){
echo $ex->getMessage();
}