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();
}

 

 

posted @ 2015-02-11 15:22  wangxusummer  阅读(21963)  评论(0编辑  收藏  举报