ngx_lua module API description

ANGX_LUA module API description

#ngx instructions Lua_Code_cache on | off;

Activity: Open or close the lua code cache, affect the following instructions: set_by_Lua_file, Content_BY_LUA_FILE, REWRITE_BY_LUA_FILE, Access_by_LUA_FILE and forced loading or RELOAD LUA module, cache, etc. Modifying the LUA code requires restarting nginx when it is enabled, but not when it is not enabled. Caching is generally turned off during the development phase.
Scope: main, server, location, location iflua_regex_cache_max_entries 1024;

Function: Unknown (seems to limit the maximum number of cached regular expression processing results)lua_package_path.../path... ;

Function: Set the extension library path written in lua code.
Example: lua_package_path '/foo/bar/?.lua;/blah/?.lua;;';lua_package_cpath '/bar/baz/?.so;/blah/blah/?.so;;';

Function: Set the lua library path of the C extension. set_by_lua $var '' [$arg1 $arg2];set_by_lua_file $var [$arg1 $arg2 ...];


Function: Set an Nginx variable, and the variable value is calculated from the Lua script and returned by return, which can implement complex assignment logic; this is blocking, and the Lua code must be very fast.
In addition, the existing ngx variable can be used as The parameters are passed into the Lua script and accessed through ngx.arg[1], ngx.arg[2], etc.
Scope: main, server, location, server if, location if
Processing stage: rewritecontent_by_lua '';content_by_lua_file luafile;


Scope: location, location if
Description: Content processor, receives request processing and outputs response. content_by_lua directly writes shorter Lua code in nginx configuration file. The latter uses lua file. rewrite_by_lua ''rewrite_by_lua_file lua_file;


Scope: http, server, location, location if
Perform internal URL rewriting or external redirection, typical such as pseudo-static URL rewriting . Its default execution is at the end of the rewrite processing phase.
Note that when using rewrite_by_lua, you cannot see the corresponding rewrite log after turning on rewrite_log on;. access_by_lua 'lua code';access_by_lua_file lua_file.lua;


Function: used for access control. For example, we only allow intranet IP access, you can use the following form.
access_by_lua '
if ngx.req.get_uri_args()["token"] ~= "123" then
return ngx.exit(403)
end ';
Scope ：http, server, location, location ifheader_filter_by_lua 'lua code';header_filter_by_lua_file path_file.lua;


Function: Set header and cookie;lua_need_request_body on|off;

Function: Whether to read the request body, follow ngx The .req.read_body() function works similarly, but this method is not officially recommended. lua_shared_dict shared_data 10m;

Function: Set up a shared global variable table to be shared among all worker processes. It can be accessed in the lua script as follows:
Example: local shared_data = ngx.shared.shared_data
10m I don’t know what it means. init_by_lua 'lua code'; init_by_lua_file lua_file.lua;


Scope: http
Description: Executed when the ginx Master process loads the configuration; usually used to initialize global configuration/preload Lua modules init_worker_by_lua 'lua code' ;init_worker_by_lua_file luafile.lua;


Scope: http

Description: A timer called when each Nginx Worker process starts. If the Master process is not allowed, it will only be called after init_by_lua; usually used for timing pulls Get configuration/data, or health check of backend service. ####################

Methods and constants ################# ####

ngx.arg[index]  			#ngx指令参数，当这个变量在set_by_lua或者set_by_lua_file内使用的时候是只读的，指的是在配置指令输入的参数.
ngx.var.varname  			#读写NGINX变量的值,最好在lua脚本里缓存变量值，避免在当前请求的生命周期内内存的泄漏
ngx.config.ngx_lua_version 	#当前ngx_lua模块版本号
ngx.config.nginx_version 	#nginx版本
ngx.worker.exiting 			#当前worker进程是否正在关闭
ngx.worker.pid				#当前worker进程的PID
ngx.config.nginx_configure	#编译时的./configure命令选项
ngx.config.prefix 			#编译时的prefix选项

core constans:				#ngx_lua 核心常量
	ngx.OK (0)
	ngx.ERROR (-1)
	ngx.AGAIN (-2)
	ngx.DONE (-4)
	ngx.DECLINED (-5)
	ngx.nil
http method constans:		#经常在ngx.location.catpure和ngx.location.capture_multi方法中被调用.
	ngx.HTTP_GET
	ngx.HTTP_HEAD
	ngx.HTTP_PUT
	ngx.HTTP_POST
	ngx.HTTP_DELETE
	ngx.HTTP_OPTIONS  
	ngx.HTTP_MKCOL    
	ngx.HTTP_COPY      
	ngx.HTTP_MOVE     
	ngx.HTTP_PROPFIND 
	ngx.HTTP_PROPPATCH 
	ngx.HTTP_LOCK 
	ngx.HTTP_UNLOCK    
	ngx.HTTP_PATCH   
	ngx.HTTP_TRACE  
http status constans: 		#http请求状态常量 
	ngx.HTTP_OK (200)
	ngx.HTTP_CREATED (201)
	ngx.HTTP_SPECIAL_RESPONSE (300)
	ngx.HTTP_MOVED_PERMANENTLY (301)
	ngx.HTTP_MOVED_TEMPORARILY (302)
	ngx.HTTP_SEE_OTHER (303)
	ngx.HTTP_NOT_MODIFIED (304)
	ngx.HTTP_BAD_REQUEST (400)
	ngx.HTTP_UNAUTHORIZED (401)
	ngx.HTTP_FORBIDDEN (403)
	ngx.HTTP_NOT_FOUND (404)
	ngx.HTTP_NOT_ALLOWED (405)
	ngx.HTTP_GONE (410)
	ngx.HTTP_INTERNAL_SERVER_ERROR (500)
	ngx.HTTP_METHOD_NOT_IMPLEMENTED (501)
	ngx.HTTP_SERVICE_UNAVAILABLE (503)
	ngx.HTTP_GATEWAY_TIMEOUT (504) 

Nginx log level constants：		#错误日志级别常量 ,这些参数经常在ngx.log方法中被使用.
	ngx.STDERR
	ngx.EMERG
	ngx.ALERT
	ngx.CRIT
	ngx.ERR
	ngx.WARN
	ngx.NOTICE
	ngx.INFO
	ngx.DEBUG

##################
#API中的方法：
##################
print()							#与 ngx.print()方法有区别，print() 相当于ngx.log()
ngx.ctx 						#这是一个lua的table，用于保存ngx上下文的变量，在整个请求的生命周期内都有效,详细参考官方
ngx.location.capture() 			#发出一个子请求，详细用法参考官方文档。
ngx.location.capture_multi() 	#发出多个子请求，详细用法参考官方文档。
ngx.status 						#读或者写当前请求的相应状态. 必须在输出相应头之前被调用.
ngx.header.HEADER 				#访问或设置http header头信息，详细参考官方文档。
ngx.req.set_uri() 				#设置当前请求的URI,详细参考官方文档
ngx.set_uri_args(args) 			#根据args参数重新定义当前请求的URI参数.
ngx.req.get_uri_args()			#返回一个LUA TABLE，包含当前请求的全部的URL参数
ngx.req.get_post_args()			#返回一个LUA TABLE，包括所有当前请求的POST参数
ngx.req.get_headers()			#返回一个包含当前请求头信息的lua table.
ngx.req.set_header()			#设置当前请求头header某字段值.当前请求的子请求不会受到影响.
ngx.req.read_body()				#在不阻塞ngnix其他事件的情况下同步读取客户端的body信息.[详细]
ngx.req.discard_body()			#明确丢弃客户端请求的body
ngx.req.get_body_data()			#以字符串的形式获得客户端的请求body内容
ngx.req.get_body_file()   	 	#当发送文件请求的时候，获得文件的名字
ngx.req.set_body_data()			#设置客户端请求的BODY
ngx.req.set_body_file()			#通过filename来指定当前请求的file data。
ngx.req.clear_header()			#清求某个请求头
ngx.exec(uri,args)				#执行内部跳转，根据uri和请求参数
ngx.redirect(uri, status)		#执行301或者302的重定向。
ngx.send_headers()				#发送指定的响应头
ngx.headers_sent 				#判断头部是否发送给客户端ngx.headers_sent=true
ngx.print(str)					#发送给客户端的响应页面
ngx.say()						#作用类似ngx.print，不过say方法输出后会换行
ngx.log(log.level,...)			#写入nginx日志
ngx.flush()						#将缓冲区内容输出到页面（刷新响应）
ngx.exit(http-status)			#结束请求并输出状态码
ngx.eof()						#明确指定关闭结束输出流
ngx.escape_uri()				#URI编码(本函数对逗号,不编码，而php的urlencode会编码)
ngx.unescape_uri()				#uri解码
ngx.encode_args(table)			#将tabel解析成url参数
ngx.decode_args(uri)			#将参数字符串编码为一个table
ngx.encode_base64(str)			#BASE64编码
ngx.decode_base64(str)			#BASE64解码
ngx.crc32_short(str)			#字符串的crs32_short哈希
ngx.crc32_long(str)				#字符串的crs32_long哈希
ngx.hmac_sha1(str)				#字符串的hmac_sha1哈希
ngx.md5(str)					#返回16进制MD5
ngx.md5_bin(str)				#返回2进制MD5
ngx.today()						#返回当前日期yyyy-mm-dd
ngx.time()						#返回当前时间戳
ngx.now()						#返回当前时间
ngx.update_time()				#刷新后返回
ngx.localtime()					#返回 yyyy-mm-dd hh:ii:ss
ngx.utctime()					#返回yyyy-mm-dd hh:ii:ss格式的utc时间
ngx.cookie_time(sec)			#返回用于COOKIE使用的时间
ngx.http_time(sec)				#返回可用于http header使用的时间		
ngx.parse_http_time(str)		#解析HTTP头的时间
ngx.is_subrequest 				#是否子请求（值为 true or false）
ngx.re.match(subject,regex,options,ctx)  	#ngx正则表达式匹配，详细参考官网
ngx.re.gmatch(subject,regex,opt)			#全局正则匹配
ngx.re.sub(sub,reg,opt)			#匹配和替换（未知）
ngx.re.gsub()					#未知
ngx.shared.DICT 				#ngx.shared.DICT是一个table 里面存储了所有的全局内存共享变量
	ngx.shared.DICT.get	 
	ngx.shared.DICT.get_stale	 
	ngx.shared.DICT.set	 
	ngx.shared.DICT.safe_set	 
	ngx.shared.DICT.add	 
	ngx.shared.DICT.safe_add	 
	ngx.shared.DICT.replace	 
	ngx.shared.DICT.delete	 
	ngx.shared.DICT.incr	 
	ngx.shared.DICT.flush_all	 
	ngx.shared.DICT.flush_expired	 
	ngx.shared.DICT.get_keys
ndk.set_var.DIRECTIVE			#不懂

#Reference documentation:
http://wiki.nginx.org/HttpLuaModuleZh#Core_constants ngx_lua official documentation

http://blog.csdn.net/imlsz/article/details/42915473 For the official Translation of the main content of the API

http://jinnianshilongnian.iteye.com/blog/2186448 Detailed examples of ngx_lua usage documentation
http://www.cnblogs.com/wangxusummer/p/4309007.html Module methods of ngx_lua A brief introduction


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