nginx lua api翻译

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>

$sum 的值最后是88。

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>

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~

  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>

  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)

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~

  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响应状态的常量

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

nginx日志的一些级别常量，一般用在 ngx.log的api中

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,…)

<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>

输出的结果是

    foo = nil    <span>79</span>

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>

结果是

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

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}

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>

    bar    nil

<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>

   dog = hello    cat = 32

<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>

    /other dog: hello world    /lua: hello

<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>

    /other dog: hello world    /lua: hello world

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>

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

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>

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

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。

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

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

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

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

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>

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>

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

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

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>

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>

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*

6本文来源gao@dai!ma.com搞$代^码!网7

搞gaodaima代码

清除某一个请求头

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>

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

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

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

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

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。

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>

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

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。

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。

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>

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。

syntax: ok, err = ngx.send_headers()

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

指定响应头。

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。

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>

syntax: ok, err = ngx.say(…)

context: rewrite_by_lua*, access_by_lua*, content_by_lua*

作用类似于ngx.print

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

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

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。

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。