Nginx proxy基本指令整理3

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本文主要针对nginx的几个主要proxy指令做一个简单的整理，另外部分指令做了实际测试，本文具体包括如下指令：

proxy_max_temp_file_size,proxy_method,proxy_next_upstream,proxy_pass,proxy_pass_header

17. proxy_max_temp_file_size

syntax:

proxy_max_temp_file_size size;

default:

proxy_max_temp_file_size 1024m;

context:

http, server, location

当从被代理的服务器接收的响应的缓冲被允许的时侯，当整个响应不合适存储到内存中时，有一部分数据将被存储到磁盘文件中，内存存储buffer的设置是根据proxy_buffer_size及proxy_buffers指令进行设置。proxy_max_temp_file_size指令设置最大的临时文件存储的尺寸。数据在写入临时文件中，一次写入多少数据是通过 proxy_temp_file_write_size 进行设置的。当proxy_max_temp_file_size指令的数值是0时关闭响应数据存储到临时文件的功能。

When buffering of responses from the proxied server is enabled, and the whole response does not fit into memory buffers set by the proxy_buffer_size and proxy_buffers directives, part of a response can be saved to a temporary file. This directive sets the maximum size of a temporary file. The size of data written to a temporary file at a time is set by the proxy_temp_file_write_size directive.

Value of zero disables buffering of responses to temporary files.

18. proxy_method

syntax:

proxy_method method;

default:

—

context:

http, server, location

指定的HTTP请求转发到代理服务器的方法代替客户端请求中使用的方法。

Specifies the HTTP method to use in requests forwarded to the proxied server instead of the method from the client request.

19. proxy_next_upstream

syntax:

proxy_next_upstream error | timeout | invalid_header

| http_500 | http_502 | http_503

| http_504 | http_404 | off ...;

default:

proxy_next_upstream error timeout;

context:

http, server, location

指定在那种情况下请求应该被传递到下一个服务器上，包括以下情况：

Error

当nginx同被代理的服务器建立连接，传送请求，或者读取一个响应过程中发生错误

Timeout

当nginx同被代理的服务器建立连接，传送请求，或者读取一个响应过程中发生超时事件

invalid_header

当被代理的服务器返回空的或者非法的响应时

http_500

当被代理的服务器返回500响应码时

http_503

当被代理的服务器返回503响应码时

http_504

当被代理的服务器返回504响应码时

http_404

当被代理的服务器返回404响应码时

off

禁止传递请求到下一个服务器

需要注意的是：在nginx还没有传递数据给客户端的过程中发生错误，nginx可以通过这个指令将请求等转发给下一个服务器。但是如果错误发生在nginx发送响应给客户端过程中，这个转发是不可能的。

It should be understood that passing a request to the next server is only possible if a client was not sent anything yet. That is, if an error or a timeout occurs in the middle of transferring a response, fixing this is impossible.

Specifies in which cases a request should be passed to the next server:

error

an error occurred while establishing a connection with the server, passing it a request, or reading the response header;

timeout

a timeout has occurred while establishing a connection with the server, passing it a request, or reading the response header;

invalid_header

a server returned empty or invalid response;

http_500

a server returned a response with the code 500;

http_502

a server returned a response with the code 502;

http_503

a server returned a response with the code 503;

http_504

a server returned a response with the code 504;

http_404

a server returned a response with the code 404;

off

disables passing a request to the next server.

20. proxy_pass

syntax:

proxy_pass URL;

default:

—

context:

location, if in location, limit_except

设置被代理服务器的协议和地址，一个可选的uri来确定那个location应该被选中。协议可以被指定为http或者https。地址能被指定为域名或者ip地址，端口号可选。

proxy_pass http://localhost:8000/uri/;

或者采用unix的domain socket规范的地址，

proxy_pass http://unix:/tmp/backend.socket:/uri/;

如果一个域名被解析成多个ip地址，则这些ip地址将被循环使用，另外还可以使用server组（反向代理的方式）作为代理地址。

如果一个请求的URI被传递给server（被代理的服务器），将遵照下面规则：

如果proxy_pass指令携带有URI，当请求传递给被代理的服务器时，那些同location指令匹配的经过规范化处理后的uri将被指令中的相关部分替代。

location /name/ {

proxy_pass http://127.0.0.1/remote/;

}

（若一个请求中 /name/部分将被 /remote/替代）

如果proxy_pass指令没有带有uri，那么一个请求的uri将保留客户端原始（没有经过任何修改的，包括规格化，（这个没有去验证））请求中相同形式传递给被代理的server。或者当处理变化后的uri时，一个完整的规范化的uri将被传递给被代理的服务器。

location /some/path/ {

proxy_pass http://127.0.0.1;

}

在1.1.12版本以前，如果proxy_pass 指令没有包括uri，在某些情况下一个原始请求的uri可能代替变换后的uri而传送给服务器。

在某些情况下，请求uri的一部分被替换了但却不能比检测到。

当一个location使用正则表达式制定的时侯，在这个情况下本指令应该不使用带有uri形式。

当uri在代理指令出现的location中时，使用rewrite指令，这种情况下相同配置将被用于处理一个请求，例如：

location /name/ {

rewrite /name/([^/]+) /users?name=$1 break;

proxy_pass http://127.0.0.1;

}

（例子中将传递给server的是：/users?name=xxxx）这个参数。

在这种情况下，该指令中指定的URI被忽略，并且一个完整改变后的请求URI传递给服务器。

一个server名称，端口号以及uri也能被通过变量指定，例如：proxy_pass http://$host$uri;

甚至：proxy_pass $request;

在这种情况下，服务器名称被搜索在配置的服务器中间进行，如果没有找到确定使用解析器。

Sets the protocol and address of a proxied server, and an optional URI to which a location should be mapped. A protocol can be specified as “http” or “https”. An address can be specified as a domain name or IP address, and an optional port:

proxy_pass http://localhost:8000/uri/;

or as a UNIX-domain socket path specified after the word “unix” and enclosed in colons:

proxy_pass http://unix:/tmp/backend.socket:/uri/;

If a domain name resolves to several addresses, all of them will be used in a round-robin fashion. In addition, an address can be specified as a server group.

A request URI is passed to the server as follows:

If proxy_pass is specified with URI, when passing a request to the server, part of a normalized request URI matching the location is replaced by a URI specified in the directive:

location /name/ {

proxy_pass http://127.0.0.1/remote/;

}

If proxy_pass is specified without URI, a request URI is passed to the server in the same form as sent by a client when processing an original request, or the full normalized request URI is passed when processing the changed URI:

location /some/path/ {

proxy_pass http://127.0.0.1;

}

Before version 1.1.12, if proxy_pass is specified without a URI, an original request URI might be passed instead of the changed URI in some cases.

In some cases, part of a request URI to be replaced cannot be determined:

When location is specified using a regular expression.

In this case, the directive should be specified without URI.

When URI is changed inside a proxied location using the rewrite directive, and this same configuration will be used to process a request (break):

location /name/ {

rewrite /name/([^/]+) /users?name=$1 break;

proxy_pass http://127.0.0.1;

}