nginx lua api translation

The lua module of nginx provides many lua function APIs for users to use, so that lua can better operate nginx

24.1 Introduction
The Nginx api for lua mentioned here refers to the nginx.conf file Use the *_by_lua and *_by_lua_file instructions to use lua code to provide specialized APIs for lua.

24.2 ngx.arg

syntax:val = ngx.arg[index]

context: set_by_lua*, body_filter_by_lua*

By using valua = ngx.arg[n] , let nginx variables be passed into lua as parameters to call lua. The usage method is as follows: the value of

<span>location</span> /foo <span>{</span><span>set</span><span>$a</span><span>32</span><span>;</span><span>set</span><span>$b</span><span>56</span><span>;</span>
 
        set_by_lua <span>$sum</span><span>'return tonumber(ngx.arg[1]) + tonumber(ngx.arg[2])'</span><span>$a</span><span>$b</span><span>;</span>
 
        echo <span>$sum</span><span>;</span><span>}</span>

$sum is 88 in the end.

24.3 ngx.var.VARIABLE

syntax:ngx.var.VAR_NAME

context: set_by_lua*, rewrite_by_lua*, access _by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua* , log_by_lua*You can read and write nginx variables through the following code

value = ngx.var.some_nginx_variable_name
ngx.var.some_nginx_variable_name=value

<span>location</span> /foo <span>{</span><span>set</span><span>$my_var</span><span>''</span><span>;</span><span><em># this line is required to create $my_var at config time</em></span>
        content_by_lua <span>'
            ngx.var.my_var = 123;
            ...
        '</span><span>;</span><span>}</span>

You can get or set the nginx.conf variable in the lua code, compare What is the difference between the nginx.arg below and the one above~

24.4 Core constants

context:init_by_lua*, set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, *log_by_lua*, ngx.timer.*Some core constants

  ngx.OK <span>(</span><span>0</span><span>)</span>
  ngx.ERROR <span>(</span>-<span>1</span><span>)</span>
  ngx.AGAIN <span>(</span>-<span>2</span><span>)</span>
  ngx.DONE <span>(</span>-<span>4</span><span>)</span>
  ngx.DECLINED <span>(</span>-<span>5</span><span>)</span>

24.5 HTTP method constants

context: init_by_lua*, set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*, ngx.timer.*

  ngx.HTTP_GET
  ngx.HTTP_HEAD
  ngx.HTTP_PUT
  ngx.HTTP_POST
  ngx.HTTP_DELETE
  ngx.HTTP_OPTIONS   (added in the v0.5.0rc24 release)
  ngx.HTTP_MKCOL     (added in the v0.8.2 release)
  ngx.HTTP_COPY      (added in the v0.8.2 release)
  ngx.HTTP_MOVE      (added in the v0.8.2 release)
  ngx.HTTP_PROPFIND  (added in the v0.8.2 release)
  ngx.HTTP_PROPPATCH (added in the v0.8.2 release)
  ngx.HTTP_LOCK      (added in the v0.8.2 release)
  ngx.HTTP_UNLOCK    (added in the v0.8.2 release)
  ngx.HTTP_PATCH     (added in the v0.8.2 release)
  ngx.HTTP_TRACE     (added in the v0.8.2 release)

Some http method constants, generally used in ngx.location.capture and ngx.location.capture_multi API calls~

24.6 HTTP status constants

context:init_by_lua*, set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*, ngx.timer.*

  value <span>=</span> ngx.HTTP_OK <span>(</span><span>200</span><span>)</span>
  value <span>=</span> ngx.HTTP_CREATED <span>(</span><span>201</span><span>)</span>
  value <span>=</span> ngx.HTTP_SPECIAL_RESPONSE <span>(</span><span>300</span><span>)</span>
  value <span>=</span> ngx.HTTP_MOVED_PERMANENTLY <span>(</span><span>301</span><span>)</span>
  value <span>=</span> ngx.HTTP_MOVED_TEMPORARILY <span>(</span><span>302</span><span>)</span>
  value <span>=</span> ngx.HTTP_SEE_OTHER <span>(</span><span>303</span><span>)</span>
  value <span>=</span> ngx.HTTP_NOT_MODIFIED <span>(</span><span>304</span><span>)</span>
  value <span>=</span> ngx.HTTP_BAD_REQUEST <span>(</span><span>400</span><span>)</span>
  value <span>=</span> ngx.HTTP_UNAUTHORIZED <span>(</span><span>401</span><span>)</span>
  value <span>=</span> ngx.HTTP_FORBIDDEN <span>(</span><span>403</span><span>)</span>
  value <span>=</span> ngx.HTTP_NOT_FOUND <span>(</span><span>404</span><span>)</span>
  value <span>=</span> ngx.HTTP_NOT_ALLOWED <span>(</span><span>405</span><span>)</span>
  value <span>=</span> ngx.HTTP_GONE <span>(</span><span>410</span><span>)</span>
  value <span>=</span> ngx.HTTP_INTERNAL_SERVER_ERROR <span>(</span><span>500</span><span>)</span>
  value <span>=</span> ngx.HTTP_METHOD_NOT_IMPLEMENTED <span>(</span><span>501</span><span>)</span>
  value <span>=</span> ngx.HTTP_SERVICE_UNAVAILABLE <span>(</span><span>503</span><span>)</span>
  value <span>=</span> ngx.HTTP_GATEWAY_TIMEOUT <span>(</span><span>504</span><span>)</span><span>(</span>first added in the v0.3.1rc38 release<span>)</span>

http response status constants

24.7 Nginx log level constants

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*, ngx.timer.*
Some level constants of

  ngx.STDERR
  ngx.EMERG
  ngx.ALERT
  ngx.CRIT
  ngx.ERR
  ngx.WARN
  ngx.NOTICE
  ngx.INFO
  ngx.DEBUG

nginx log, generally used in the ngx.log API

24.8 print

syntax: print(...)

context:init_by_lua*, init_worker_by_lua*, set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*, ngx.timer.*This API uses the log level of ngx.NOTICE to write the parameter value into the error.log file, which is equivalent to ngx.log(ngx.NOTICE,...)

24.9 ngx.ctx

context:init_worker_by_lua*, set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*, ngx.timer.*
ngx.ctx.xxx xxx is any variable name, ngx.ctx can be regarded as a temporary dictionary, The scope is each request, which means that different requests have different ngx.ctxAs in the example below

<span>location</span> /test <span>{</span>
        rewrite_by_lua <span>'
            ngx.say("foo = ", ngx.ctx.foo)
            ngx.ctx.foo = 76
        '</span><span>;</span>
        access_by_lua <span>'
            ngx.ctx.foo = ngx.ctx.foo + 3
        '</span><span>;</span>
        content_by_lua <span>'
            ngx.say(ngx.ctx.foo)
        '</span><span>;</span><span>}</span>

, the output result is

    foo = nil
    <span>79</span>

This instance of ngx.ctx.foo is used in rewrite, access and There are three cycles of content.
Look at the example below again

<span>location</span> /sub <span>{</span>
        content_by_lua <span>'
            ngx.say("sub pre: ", ngx.ctx.blah)
            ngx.ctx.blah = 32
            ngx.say("sub post: ", ngx.ctx.blah)
        '</span><span>;</span><span>}</span>
 
    <span>location</span> /main <span>{</span>
        content_by_lua <span>'
            ngx.ctx.blah = 73
            ngx.say("main pre: ", ngx.ctx.blah)
            local res = ngx.location.capture("/sub")
            ngx.print(res.body)
            ngx.say("main post: ", ngx.ctx.blah)
        '</span><span>;</span><span>}</span>

The result is

    main pre: <span>73</span>
    sub pre: nil
    sub post: <span>32</span>
    main post: <span>73</span>

ngx.location.capture is requesting another link, so you can see that ngx.ctx in sub and main are different instances.
In addition, in the init_worker_by_lua instruction, we can initialize ngx.ctx in the form of a dictionary
ngx.ctx = {foo = 32, bar = 54}

24.10 ngx.location.capture

syntax: res = ngx.location.capture(uri, options?)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*通过这个api，lua可以访问本server的其他location，只能是同一个server的。用法如下

 res <span>=</span> ngx.location.capture<span>(</span>uri<span>)</span>

返回的是一个response对象，这个对象持有其他包括res.status、res.body以及res.header三个对象。
-capture函数除了url还有其他参数可以选择，包括
-method  设置访问的method类型
-body 设置访问子请求的httpbody内容
-args设置请求的参数

    ngx.location.capture<span>(</span><span>'/foo?a=1'</span>,
        <span>{</span> args <span>=</span><span>{</span> b <span>=</span><span>3</span>, c <span>=</span><span>':'</span><span>}</span><span>}</span><span>)</span>

等价于下面的调用，都是传递请求参数

    ngx.location.capture<span>(</span><span>'/foo?a=1&b=3&c=%3a'</span><span>)</span>

-ctx 之前在ngx.ctx说的，在一个请求中独享一个ngx.ctx。但是在这里通过ctx，可以传入一个字典，然后通过子请求设置ngx.ctx的值，从而，我们在父请求中得到子请求ngx.ctx的值。

<span>location</span> /sub <span>{</span>
        content_by_lua <span>'
            ngx.ctx.foo = "bar";
        '</span><span>;</span><span>}</span><span>location</span> /lua <span>{</span>
        content_by_lua <span>'
            local ctx = {}
            res = ngx.location.capture("/sub", { ctx = ctx })
 
            ngx.say(ctx.foo);
            ngx.say(ngx.ctx.foo);
        '</span><span>;</span><span>}</span>

结果如下,仅仅是设置ctx这个字典的值，而不是共享ngx.ctx

    bar
    nil

-vars 这个参数用来在父请求中设置nginx的变量值并向子请求传递，这个方法比通过url参数传递更加有效果。

<span>location</span> /other <span>{</span>
        content_by_lua <span>'
            ngx.say("dog = ", ngx.var.dog)
            ngx.say("cat = ", ngx.var.cat)
        '</span><span>;</span><span>}</span>
 
    <span>location</span> /lua <span>{</span><span>set</span><span>$dog</span><span>''</span><span>;</span><span>set</span><span>$cat</span><span>''</span><span>;</span>
        content_by_lua <span>'
            res = ngx.location.capture("/other",
                { vars = { dog = "hello", cat = 32 }});
 
            ngx.print(res.body)
        '</span><span>;</span><span>}</span>

结果如下

   dog = hello
    cat = 32

-copy_all_vars 拷贝父请求的nginx的变量给子请求

<span>location</span> /other <span>{</span><span>set</span><span>$dog</span><span>"$dog world"</span><span>;</span>
        echo <span>"$uri dog: $dog"</span><span>;</span><span>}</span>
 
    <span>location</span> /lua <span>{</span><span>set</span><span>$dog</span><span>'hello'</span><span>;</span>
        content_by_lua <span>'
            res = ngx.location.capture("/other",
                { copy_all_vars = true });
 
            ngx.print(res.body)
            ngx.say(ngx.var.uri, ": ", ngx.var.dog)
        '</span><span>;</span><span>}</span>

结果如下

    /other dog: hello world
    /lua: hello

-share_all_vars 同享父请求和子请求的nginx的变量。

<span>location</span> /other <span>{</span><span>set</span><span>$dog</span><span>"$dog world"</span><span>;</span>
        echo <span>"$uri dog: $dog"</span><span>;</span><span>}</span>
 
    <span>location</span> /lua <span>{</span><span>set</span><span>$dog</span><span>'hello'</span><span>;</span>
        content_by_lua <span>'
            res = ngx.location.capture("/other",
                { share_all_vars = true });
 
            ngx.print(res.body)
            ngx.say(ngx.var.uri, ": ", ngx.var.dog)
        '</span><span>;</span><span>}</span>

结果如下

    /other dog: hello world
    /lua: hello world

这个比copy_all_vars优先。
-always_forward_body 如果body属性没有设置，这个属性设置为true，那将发送父请求的httpbody给子请求。

24.11 ngx.location.capture_multi

syntax: res1, res2, ... = ngx.location.capture_multi({ {uri, options?}, {uri, options?}, ... })

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

类似于上面的ngx.location.capture ，不过支持并行请求多个子请求

 res1, res2, res3 <span>=</span> ngx.location.capture_multi<span>{</span><span>{</span><span>"/foo"</span>, <span>{</span> args <span>=</span><span>"a=3&b=4"</span><span>}</span><span>}</span>,
        <span>{</span><span>"/bar"</span><span>}</span>,
        <span>{</span><span>"/baz"</span>, <span>{</span> method <span>=</span> ngx.HTTP_POST, body <span>=</span><span>"hello"</span><span>}</span><span>}</span>,
    <span>}</span>
 
    <span>if</span> res1.status <span>==</span> ngx.HTTP_OK <span>then</span>
        ...
    <span>end</span>
 
    <span>if</span> res2.body <span>==</span><span>"BLAH"</span><span>then</span>
        ...
    <span>end</span>

<span><em>-- construct the requests table</em></span><span>local</span> reqs <span>=</span><span>{</span><span>}</span><span>table.insert</span><span>(</span>reqs, <span>{</span><span>"/mysql"</span><span>}</span><span>)</span><span>table.insert</span><span>(</span>reqs, <span>{</span><span>"/postgres"</span><span>}</span><span>)</span><span>table.insert</span><span>(</span>reqs, <span>{</span><span>"/redis"</span><span>}</span><span>)</span><span>table.insert</span><span>(</span>reqs, <span>{</span><span>"/memcached"</span><span>}</span><span>)</span>
 
    <span><em>-- issue all the requests at once and wait until they all return</em></span><span>local</span> resps <span>=</span><span>{</span> ngx.location.capture_multi<span>(</span>reqs<span>)</span><span>}</span>
 
    <span><em>-- loop over the responses table</em></span><span>for</span> i, resp <span>in</span><span>ipairs</span><span>(</span>resps<span>)</span><span>do</span><span><em>-- process the response table "resp"</em></span><span>end</span>

24.12 ngx.status
context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*
读取或者设置当前的请求响应状态，这个应该在发送内容给浏览器之前执行

    ngx.status <span>=</span> ngx.HTTP_CREATED
    status <span>=</span> ngx.status

24.13 ngx.header.HEADER

syntax: ngx.header.HEADER = VALUE

syntax: value = ngx.header.HEADER

context: rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*

获取或者设置http header的值

<span><em>-- equivalent to ngx.header["Content-Type"] = 'text/plain'</em></span>
    ngx.header.content_type <span>=</span><span>'text/plain'</span><span>;</span>
 
    ngx.header<span>[</span><span>"X-My-Header"</span><span>]</span><span>=</span><span>'blah blah'</span><span>;</span>

多个值的可以像下面那样设置

    ngx.header<span>[</span><span>'Set-Cookie'</span><span>]</span><span>=</span><span>{</span><span>'a=32; path=/'</span>, <span>'b=4; path=/'</span><span>}</span>

    Set-Cookie: <span>a</span>=<span>32</span>; <span>path</span>=<span>/</span>
    Set-Cookie: <span>b</span>=<span>4</span>; <span>path</span>=<span>/</span>

特别是在header_filter_by_lua有效果，如

<span>location</span> /test <span>{</span><span>set</span><span>$footer</span><span>''</span><span>;</span>
 
        <span>proxy_pass</span><span>http</span>://some-backend<span>;</span>
 
        header_filter_by_lua <span>'
            if ngx.header["X-My-Header"] == "blah" then
                ngx.var.footer = "some value"
            end
        '</span><span>;</span>
 
        echo_after_body <span>$footer</span><span>;</span><span>}</span>

24.14 ngx.resp.get_headers

syntax: headers = ngx.resp.get_headers(max_headers?, raw?)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*

<span>local</span> h <span>=</span> ngx.resp.get_headers<span>(</span><span>)</span><span>for</span> k, v <span>in</span><span>pairs</span><span>(</span>h<span>)</span><span>do</span>
    ...
<span>end</span>

在lua中得到http请求的响应头，以字典的形式

24.15 ngx.req.start_time

syntax: secs = ngx.req.start_time()

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*, log_by_lua*

<span>local</span> request_time <span>=</span> ngx.now<span>(</span><span>)</span> - ngx.req.start_time<span>(</span><span>)</span>

用来获取此次请求发起的时候的时间，用来模拟$request_time。

24.16 ngx.req.http_version

syntax: num = ngx.req.http_version()

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*

获取请求的http version

24.17 ngx.req.raw_header

syntax: str = ngx.req.raw_header(no_request_line?)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*

得到原http header的字符串文本内容

  ngx.<span>print</span><span>(</span>ngx.req.raw_header<span>(</span><span>)</span><span>)</span>

结果是

    GET /t HTTP/1.1
    Host: localhost
    Connection: close
    Foo: bar

24.18 ngx.req.get_method

syntax: method_name = ngx.req.get_method()

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*

获得当前请求的method 名字

24.19 ngx.req.set_method

syntax: ngx.req.set_method(method_id)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*

设置覆盖此次请求的method名字

24.20 ngx.req.set_uri

syntax: ngx.req.set_uri(uri, jump?)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*

作用与rewrite相同，其中jump默认为false，false的时候

  ngx.req.set_uri<span>(</span><span>"/foo"</span>, <span>false</span><span>)</span>

结果是

<span>rewrite</span> ^ /foo <span>break</span><span>;</span>

如果jump为true，那就是

ngx.req.set_uri<span>(</span><span>"/foo"</span>, <span>true</span><span>)</span>

结果是

<span>rewrite</span> ^ /foo last<span>;</span>

24.21 ngx.req.set_uri_args

syntax: ngx.req.set_uri_args(args)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*

rewrite当前的请求参数

ngx.req.set_uri_args<span>(</span><span>"a=3&b=hello%20world"</span><span>)</span>

或者

ngx.req.set_uri_args<span>(</span><span>{</span> a <span>=</span><span>3</span>, b <span>=</span><span>"hello world"</span><span>}</span><span>)</span>

24.22 ngx.req.get_uri_args

syntax: args = ngx.req.get_uri_args(max_args?)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*

获得请求的参数

<span>location</span><span>=</span> /test <span>{</span>
        content_by_lua <span>'
            local args = ngx.req.get_uri_args()
            for key, val in pairs(args) do
                if type(val) == "table" then
                    ngx.say(key, ": ", table.concat(val, ", "))
                else
                    ngx.say(key, ": ", val)
                end
            end
        '</span><span>;</span><span>}</span>

当访问的是 GET /test?foo=bar&bar=baz&bar=blah 结果就是

   foo: bar
    bar: baz, blah

24.23 ngx.req.get_post_args

syntax: args, err = ngx.req.get_post_args(max_args?)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*

得到post提交的参数

<span>location</span><span>=</span> /test <span>{</span>
        content_by_lua <span>'
            ngx.req.read_body()
            local args, err = ngx.req.get_post_args()
            if not args then
                ngx.say("failed to get post args: ", err)
                return
            end
            for key, val in pairs(args) do
                if type(val) == "table" then
                    ngx.say(key, ": ", table.concat(val, ", "))
                else
                    ngx.say(key, ": ", val)
                end
            end
        '</span><span>;</span><span>}</span>

当我们用curl提交参数时

<span><em># Post request with the body 'foo=bar&bar=baz&bar=blah'</em></span>
    $ curl <span>--data</span><span>'foo=bar&bar=baz&bar=blah'</span> localhost<span>/</span><span>test</span>

结果是

    foo: bar
    bar: baz, blah

24.24 ngx.req.get_headers

syntax: headers = ngx.req.get_headers(max_headers?, raw?)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua, log_by_lua*

获取当前请求的头信息

<span>local</span> h <span>=</span> ngx.req.get_headers<span>(</span><span>)</span><span>for</span> k, v <span>in</span><span>pairs</span><span>(</span>h<span>)</span><span>do</span>
        ...
    <span>end</span>

    ngx.say<span>(</span><span>"Host: "</span>, ngx.req.get_headers<span>(</span><span>)</span><span>[</span><span>"Host"</span><span>]</span><span>)</span>

24.25 ngx.req.set_header

syntax: ngx.req.set_header(header_name, header_value)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua

设置当前的请求头

 ngx.req.set_header<span>(</span><span>"Content-Type"</span>, <span>"text/css"</span><span>)</span>

  ngx.req.set_header<span>(</span><span>"Foo"</span>, <span>{</span><span>"a"</span>, <span>"abc"</span><span>}</span><span>)</span>

24.26 ngx.req.clear_header

syntax: ngx.req.clear_header(header_name)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*

清除某一个请求头

24.27 ngx.req.read_body

syntax: ngx.req.read_body()

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

在不阻塞nginx事件轮询的情况下读取客户端请求的body

    ngx.req.read_body<span>(</span><span>)</span><span>local</span> args <span>=</span> ngx.req.get_post_args<span>(</span><span>)</span>

24.28 ngx.req.discard_body

syntax: ngx.req.discard_body()

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

明确丢弃客户端请求body

24.29 ngx.req.get_body_data

syntax: data = ngx.req.get_body_data()

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

以字符串的形式获得客户端的请求body内容

24.30 ngx.req.get_body_file

syntax: file_name = ngx.req.get_body_file()

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

当发送文件请求的时候，获得文件的名字

24.31 ngx.req.set_body_data

syntax: ngx.req.set_body_data(data)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

设置客户端请求的body

24.32 ngx.req.set_body_file

syntax: ngx.req.set_body_data(data)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

通过filename来指定当前请求的file data。

24.33 ngx.req.init_body

syntax: ngx.req.init_body(buffer_size?)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*

创建一个当前请求的空白body的buffer，后续可以自己写入请求的body。

  ngx.req.init_body<span>(</span><span>128</span><span>*</span><span>1024</span><span>)</span><span><em>-- buffer is 128KB</em></span><span>for</span> chunk <span>in</span> next_data_chunk<span>(</span><span>)</span><span>    do</span>
        ngx.req.append_body<span>(</span>chunk<span>)</span><span><em>-- each chunk can be 4KB</em></span><span>end</span>
    ngx.req.finish_body<span>(</span><span>)</span>

24.34 ngx.req.append_body

syntax: ngx.req.append_body(data_chunk)

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*

追加当前请求的http body

24.35 ngx.req.finish_body

syntax: ngx.req.finish_body()

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*

标志完成ngx.req.init_body的数据追加。

24.36 ngx.req.socket

syntax: tcpsock, err = ngx.req.socket()

syntax: tcpsock, err = ngx.req.socket(raw)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

这个方法会返回一个只读的cosocket对象，用来读取当前请求的request http body内容。

24.37 ngx.exec

syntax: ngx.exec(uri, args?)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

执行内部跳转根据url和请求参数

   ngx.exec<span>(</span><span>'/some-location'</span><span>)</span><span>;</span>
    ngx.exec<span>(</span><span>'/some-location'</span>, <span>'a=3&b=5&c=6'</span><span>)</span><span>;</span>
    ngx.exec<span>(</span><span>'/some-location?a=3&b=5'</span>, <span>'c=6'</span><span>)</span><span>;</span>

<span>location</span> /foo <span>{</span>
        content_by_lua <span>'
            ngx.exec("@bar", "a=goodbye");
        '</span><span>;</span><span>}</span>
 
    <span>location</span><span>@bar</span><span>{</span>
        content_by_lua <span>'
            local args = ngx.req.get_uri_args()
            for key, val in pairs(args) do
                if key == "a" then
                    ngx.say(val)
                end
            end
        '</span><span>;</span><span>}</span>

24.38 ngx.redirect

syntax: ngx.redirect(uri, status?)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

执行301或者302的重定向。

24.39 ngx.send_headers

syntax: ok, err = ngx.send_headers()

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

指定响应头。

24.40 ngx.headers_sent

syntax: value = ngx.headers_sent

context: set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*

判断头部是否发送给客户端了。

24.41 ngx.print

syntax: ok, err = ngx.print(...)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

发送数据给客户端响应页面

<span>local</span><span>table</span><span>=</span><span>{</span><span>"hello, "</span>,
        <span>{</span><span>"world: "</span>, <span>true</span>, <span>" or "</span>, <span>false</span>,
            <span>{</span><span>": "</span>, <span>nil</span><span>}</span><span>}</span><span>}</span>
    ngx.<span>print</span><span>(</span><span>table</span><span>)</span>

24.42 ngx.say

syntax: ok, err = ngx.say(...)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

作用类似于ngx.print

24.43 ngx.log

syntax: ngx.log(log_level, ...)

context: init_by_lua*, init_worker_by_lua*, set_by_lua*, rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*, log_by_lua*, ngx.timer.*

向error.log中记录日志

24.44 ngx.flush

syntax: ok, err = ngx.flush(wait?)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

将flush内容到客户端页面

24.45 ngx.exit

syntax: ngx.exit(status)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, ngx.timer.*

    ngx.status <span>=</span> ngx.HTTP_GONE
    ngx.say<span>(</span><span>"This is our own content"</span><span>)</span><span><em>-- to cause quit the whole request rather than the current phase handler</em></span>
    ngx.<span>exit</span><span>(</span>ngx.HTTP_OK<span>)</span>

当status>=200的时候，直接停止当前请求的后续操作，并且返回状态码
当status==0的时候，跳过此次代码片段，并且继续执行下面的。

24.46 ngx.eof

syntax: ok, err = ngx.eof()

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

<span>location</span><span>=</span> /async <span>{</span><span>keepalive_timeout</span><span>0</span><span>;</span>
        content_by_lua <span>'
            ngx.say("got the task!")
            ngx.eof()  -- a descent HTTP client will close the connection at this point
            -- access MySQL, PostgreSQL, Redis, Memcached, and etc here...
        '</span><span>;</span><span>}</span>

明确指定关闭结束输出流。

24.47 ngx.sleep

24.48 ngx.escape_uri

24.49 ngx.unescape_uri

24.50 ngx.encode_args

24.51 ngx.decode_args

24.52 ngx.encode_base64

24.53 ngx.decode_base64

24.54 ngx.crc32_short

24.55 ngx.crc32_long

24.56 ngx.hmac_sha1

24.57 ngx.md5

24.58 ngx.md5_bin

24.59 ngx.sha1_bin

24.60 ngx.quote_sql_str

24.61 ngx.today

24.62 ngx.time

24.63 ngx.now

24.64 ngx.update_time

24.65 ngx.localtime

24.66 ngx.utctime

24.67 ngx.cookie_time

24.68 ngx.http_time

24.69 ngx.parse_http_time

24.70 ngx.is_subrequest

24.71 ngx.re.match

24.72 ngx.re.find

24.73 ngx.re.gmatch

24.74 ngx.re.sub

24.75 ngx.re.gsub

24.76 ngx.shared.DICT

24.77 ngx.shared.DICT.get

24.78 ngx.shared.DICT.get_stale

24.79 ngx.shared.DICT.set

24.80 ngx.shared.DICT.safe_set

24.81 ngx.shared.DICT.add

24.82 ngx.shared.DICT.safe_add

24.83 ngx.shared.DICT.replace

24.84 ngx.shared.DICT.delete

24.85 ngx.shared.DICT.incr

24.86 ngx.shared.DICT.flush_all

24.87 ngx.shared.DICT.flush_expired

24.88 ngx.shared.DICT.get_keys

24.89 ngx.socket.udp

24.90 udpsock:setpeername

24.91 udpsock:send

24.92 udpsock:receive

24.93 udpsock:close

24.94 udpsock:settimeout

24.95 ngx.socket.tcp

24.96 tcpsock:connect

24.97 tcpsock:sslhandshake

24.98 tcpsock:send

24.99 tcpsock:receive

24.100 tcpsock:receiveuntil

24.101 tcpsock:close

24.102 tcpsock:settimeout

24.103 tcpsock:setoption

24.104 tcpsock:setkeepalive

24.105 tcpsock:getreusedtimes

24.106 ngx.socket.connect

24.107 ngx.get_phase

24.108 ngx.thread.spawn

24.109 ngx.thread.wait

24.110 ngx.thread.kill

24.111 ngx.on_abort

24.112 ngx.timer.at

24.113 ngx.config.debug

24.114 ngx.config.prefix

24.115 ngx.config.nginx_version

24.116 ngx.config.nginx_configure

24.117 ngx.config.ngx_lua_version

24.118 ngx.worker.exiting

24.119 ngx.worker.pid

24.120 ndk.set_var.DIRECTIVE

24.121 coroutine.create

24.122 coroutine.resume

24.123 coroutine.yield

24.124 coroutine.wrap

24.125 coroutine.running

24.126 coroutine.status

以上就介绍了nginx lua api翻译，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。