nginx lua api翻译-tutorial php-php.cn

nginx的lua模块提供了很多lua的函数API给用户使用，以便让lua更好的操作nginx

24.1 Introduction
这里说的Nginx api for lua，指的就是在nginx.conf文件中用*_by_lua 和*_by_lua_file指令使用lua代码，为lua提供的专门的api。

24.2 ngx.arg

syntax: val = ngx.arg[index]

context: set_by_lua*, body_filter_by_lua*

通过用valua = ngx.arg[n]，让nginx的变量作为参数传入lua给lua调用，使用方式如下列的代码

<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>

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$sum 的值最后是88。

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*

可以通过以下的代码进行读写nginx的变量
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>

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在lua代码里面就可以得到或者设置nginx.conf的变量，比较下跟上面的nginx.arg有什么区别~

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.*
一些核心常量

  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>

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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)

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一些http method的常量，一般用在ngx.location.capture 和ngx.location.capture_multi 这几个API的调用中~

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>

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http响应状态的常量

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.*

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

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nginx日志的一些级别常量，一般用在 ngx.log的api中

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.*

这个API是采用ngx.NOTICE的日志级别将参数的值写入error.log文件中，等同于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是任意的一个变量名，ngx.ctx可以看成一个临时字典，作用域是每一个请求，也就是说不同的request是不同的ngx.ctx
如下面的例子

<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>

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输出的结果是

    foo = nil
    <span>79</span>

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这个ngx.ctx.foo的实例是贯穿在一个请求中rewrite、access还有content三个周期。
再看下面这个例子

<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>

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结果是

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

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ngx.location.capture是请求另外一个链接，所以可以看到，sub和main中的ngx.ctx是不同的实例。
另外在init_worker_by_lua的指令中，我们可以初始化ngx.ctx，通过字典的形式
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>

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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>

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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>

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-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>

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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

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-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>

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结果如下

   dog = hello
    cat = 32

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-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>

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结果如下

    /other dog: hello world
    /lua: hello

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-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>

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结果如下

    /other dog: hello world
    /lua: hello world

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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>

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<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>

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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

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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>

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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>

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    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>

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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>

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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>

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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>

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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>

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结果是

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

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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>

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结果是

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

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如果jump为true，那就是

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

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结果是

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

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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>

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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>

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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>

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

   foo: bar
    bar: baz, blah

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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>

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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>

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结果是

    foo: bar
    bar: baz, blah

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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>

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

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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>

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

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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>

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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>

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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>

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<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>

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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>

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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>

Salin selepas log masuk

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>

Salin selepas log masuk

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