HttpCoreModuleChs

= 概要 =

控制Nginx HTTP 进程的核心属性.

= 指令 =

alias
语法: alias file-path|directory-path;

默认值: no

作用域: location

该指令设置指定location使用的路径.注意它跟  相似,但是不改变文件的根路径,仅仅是使用文件系统路径

比如:

location /i/ { alias /spool/w3/images/; }

请求 "/i/top.gif" 将返回文件 "/spool/w3/images/top.gif".

在替换路径中可以使用变量.

无法在正则的 中使用. 如果你需要这么做,你必须结合使用指令 和.

client_body_in_file_only
语法: client_body_in_file_only on|off

默认值: off

作用域: http, server, location

The directive enables to store a client request body in a file.

Please note that the file at the request completion will not be removed if the directive is enabled.

This directive can be used for debugging and for the  method in the Embedded Perl module.

client_body_buffer_size
syntax: client_body_buffer_size the_size

default: 8k/16k

context: http, server, location

The directive specifies the client request body buffer size.

If the request body is more than the buffer, then the entire request body or some part is written in a temporary file.

The default size is equal to two pages size, depending on platform it is either 8K or 16K.

client_body_temp_path
syntax: client_body_temp_path dir-path [ level1 [ level2 [ level3 ]    

default: client_body_temp

context: http, server, location

The directive assigns the directory for storing the temporary files in it with the body of the request.

In the  a hierarchy of subdirectories up to three levels are possible.

For example

client_body_temp_path /spool/nginx/client_temp 1 2; The directory structure will be like this:

/spool/nginx/client_temp/7/45/00000123457

client_body_timeout
syntax: client_body_timeout time

default: 60

context: http, server, location

Directive sets the read timeout for the request body from client.

The timeout is set only if a body is not get in one readstep. If after this time the client send nothing, nginx returns error "Request time out" (408).

client_header_buffer_size
syntax: client_header_buffer_size size

default: 1k

context: http, server

Directive sets the headerbuffer size for the request header from client.

For the overwhelming majority of requests it is completely sufficient a buffer size of 1K.

However if a big cookie is in the request-header or the request has come from a wap-client the header can not be placed in 1K, therefore, the request-header or a line of request-header is not located completely in this buffer nginx allocate a bigger buffer, the size of the bigger buffer can be set with the instruction large_client_header_buffers.

client_header_timeout
syntax: client_header_timeout time

default: 60

context: http, server

Directive assigns timeout with reading of the title of the request of client.

The timeout is set only if a header is not get in one readstep. If after this time the client send nothing, nginx returns error "Request time out" (408).

client_max_body_size
syntax: client_max_body_size size

default: client_max_body_size 1m

context: http, server, location

Directive assigns the maximum accepted body size of client request, indicated by the line  in the header of request.

If size is greater the given one, then the client gets the error "Request Entity Too Large" (413).

It is necessary to keep in mind that the browsers do not know how to correctly show this error.

default_type
syntax: default_type MIME-type

default: default_type text/plain

context: http, server, location

Assigns the default MIME-type to be used for files where the standard MIME map doesn't specify anything.

See also types

Example:

location = /proxy.pac { default_type application/x-ns-proxy-autoconfig; } location = /wpad.dat { rewrite. /proxy.pac; default_type application/x-ns-proxy-autoconfig; }

directio
syntax: directio [size|off]

default: directio off

context: http, server, location

The directive enables use of flags O_DIRECT (FreeBSD, Linux), F_NOCACHE (Mac OS X) or directio function (Solaris) for reading files with size greater than specified. This directive disables use of sendfile for this request. This directive may be useful for big files: directio 4m;

error_page
syntax: ''error_page code [ code... ] [ = |=answer-code ]  uri''

default: no

context: http, server, location, if in location

The directive specifies the URI, which will be showed for the errors indicated.

Example: error_page  404          /404.html; error_page  502 503 504  /50x.html; error_page  403          http://example.com/forbidden.html; Furthermore, it is possible to change the code of answer to another, for example:

error_page 404 =200 /.empty.gif; If an erroneous answer is processed by the proxied or FastCGI server and this server can return the different answer codes, for example, 200, 302, 401 or 404, then it is possible to hide the code returned:

error_page  404  =  /404.php;

If you wish to return the error code as-is, OMIT the = from the error_page directive: error_page  404  /404.php;

if_modified_since
syntax: if_modified_since [off|exact|before]

default: if_modified_since exact

context: http, server, location

The directive (0.7.24) defines how to compare time of file modification and time in request header "If-Modified-Since":
 * off — don't check "If-Modified-Since" request header (0.7.34);
 * exact — exact match;
 * before — file modification time should be less than time in "If-Modified-Since" request header.

index
syntax: index file [file...] 

default: index index.html

context: http, server, location

Directive determines the file(s) which will be used as the index. It's possible to use variables in the name of file. The presence of the files is checked in the order of their enumeration. A file with an absolute path can be put at the end. Example using a variable: index index.$geo.html  index.0.html  /index.html;

If you want to automatically generate an index from a directory listing, use autoindex on.

internal
syntax: internal

default: no

context: location

internal indicates that the matching location can be used only for so called "internal" requests.

For external requests it will return the error "Not found" (404).

Internal requests are the following:
 * requests redirected by the instruction error_page
 * subrequests created by the command include virtual of the "ngx_http_ssi_module" module
 * requests changed by the instruction rewrite of the "ngx_http_rewrite_module" module

An example to prevent clients fetching error pages directly: error_page 404 /404.html; location /404.html { internal; }

Nginx 0.7.x introduces a new syntax for internal locations:

Example: location / { root /var/www/html; error_page 404 @40x; }

location @40x { root /var/www/errors/40x.html; }

keepalive_timeout
syntax: keepalive_timeout time [ time ] 

default: keepalive_timeout 75

context: http, server, location

Directive assigns the timeout, for keep-alive connections with the client.

The second parameter assigns value in the line  in the header of response.

The parameters can differ from each other. Line  understands Mozilla and Konqueror. MSIE itself shuts keep-alive connection approximately after 60 seconds.

large_client_header_buffers
syntax: large_client_header_buffers number size

default: large_client_header_buffers 4 4k/8k

context: http, server

Directive assigns the maximum number and size of buffers for large headers to read from client request.

The request line can not be bigger then the size of one buffer, if the client send a bigger header nginx returns error "Request URI too large" (414).

The longest header line of request also must be not more than the size of one buffer, otherwise the client get the error "Bad request" (400).

Buffers are separated only as needed.

By default the size of one buffer is equal to the size of page, depending on platform this either 4K or 8K, if at the end of working request connection converts to state keep-alive, then these buffers are freed.

limit_except
syntax: limit_except methods {...}

default: no

context: location

Directive limits HTTP-methods, accessible inside location.

For the limitation can be used the directives of modules ngx_http_access_module and ngx_http_auth_basic_module:

limit_except GET { allow 192.168.1.0/32; deny  all; }

limit_rate
syntax: limit_rate speed

default: no

context: http, server, location, if in location

Directive assigns the speed of transmission of the answer to client. Speed is assigned in the bytes per second. Limitation works only for one connection, i.e., if client opens 2 connections, then total velocity will be 2 times higher then the limit set.

If it is necessary to limit speed for the part of the clients at the server level, based on some kind of condition - then this directive does not apply. Instead you should specify the limit by assigning the value to the $limit_rate variable, as shown below:

server { if ($slow) { set $limit_rate 4k; } }

listen
syntax: listen address:port [ default [ backlog=num | rcvbuf=size | sndbuf=size | accept_filter=filter | deferred | bind | ssl ]  

default: listen 80

context: server

The listen directive specifies the address and port accepted by the enclosing server {...} block. It is possible to specify only an address, only a port, or a server name as the address.

listen 127.0.0.1:8000; listen 127.0.0.1; listen 8000; listen *:8000; listen localhost:8000;

If only address is given, the default port is 80.

If the directive has the default parameter, then the enclosing server {...} block will be the default server for the address:port pair. This is useful for name-based virtual hosting where you wish to specify the default server block for hostnames that do not match any [#server_name server_name] directives. If there are no directives with the  parameter, then the default server will be the first server block in which the   pair appears.

The  directive accepts several parameters, specific to the system calls   and. These parameters must follow the  parameter.

backlog=num -- is assigned parameter backlog in call. By default backlog equals -1.

rcvbuf=size -- assigned to the parameter  for the listening socket.

sndbuf=size -- assigned to the parameter  for the listening socket.

accept_filter=filter -- is assigned name accept-filter.


 * . It works only to FreeBSD, it is possible to use two filters --  and  . On the signal -HUP accept-filter it is possible to change only in the quite last versions FreeBSD: 6.0, 5.4-STABLE and 4.11-STABLE.

deferred -- indicates to use that postponed accept(2) on Linux with


 * . the aid of option.

bind -- indicates that it is necessary to make  separately


 * . for this pair of address:port. The fact is that if are described several directives listen with the identical port, but by different addresses and one of the directives listen listens to on all addresses for this port (*:port), then nginx will make bind(2) only to *:port. It is necessary to consider that in this case for determining the address, on which the connections arrive, is done the system call getsockname. But if are used parameters backlog, rcvbuf, sndbuf, accept_filter or deferred, then it is always done separately for this pair of address:port bind(2).

ssl -- parameter (0.7.14) not related to listen(2) and bind(2) syscalls


 * . but instead specifies that connections accepted on this port should work in SSL mode. This allows to specify compact configurations for servers working with both HTTP and HTTPS. For example:

listen 80; listen 443 default ssl;

Example of the use of the parameters: listen 127.0.0.1 default accept_filter=dataready backlog=1024;

location
syntax: ''location [=|~|~*|^~] /uri/ { ... }''

default: no

context: server

This directive allows different configurations depending on the URI. It can be configured using both literal strings and regular expressions. To use regular expressions, you must use the a prefix:
 * 1)    for case insensitive matching
 * 2)    for case sensitive matching

To determine which location directive matches a particular query, the literal strings are checked first. Literal strings match the beginning portion of the query and are case-sensitive - the most specific match will be used (see below on how nginx determines this). Afterwards, regular expressions are checked in the order defined in the configuration file. The first regular expression to match the query will stop the search. If no regular expression matches are found, the result from the literal string search is used.

There are two ways to modify this behavior. The first is to use the prefix "=", which matches an exact query only. If the query matches, then searching stops and the request is handled immediately. For example, if the request "/" occurs frequently, then using "location = /" will expedite the processing of this request.

The second is to use the prefix. This prefix is used with a literal string and tells nginx to not check regular expressions if the path provided is a match. For instance, "location  /images/" would halt searching if the query begins with /images/ - all regular expression directives would not be checked.

To summarize, the order in which directives are checked is as follows:


 * 1)  Directives with the   prefix that match the query exactly. If found, searching stops.
 * 2)  All remaining directives with conventional strings. If this match used the   prefix, searching stops.
 * 3)  Regular expressions, in the order they are defined in the configuration file.
 * 4)  If #3 yielded a match, that result is used. Otherwise, the match from #2 is used.

It is important to know that nginx does the comparison against decoded URIs. For example, if you wish to match "/images/%20/test", then you must use "/images/ /test" to determine the location.

Example:

location = / { # matches the query / only. [ configuration A ] } location / { # matches any query, since all queries begin with /, but regular # expressions and any longer conventional blocks will be # matched first. [ configuration B ] } location ^~ /images/ { # matches any query beginning with /images/ and halts searching, # so regular expressions will not be checked. [ configuration C ] } location ~* \.(gif|jpg|jpeg)$ { # matches any request ending in gif, jpg, or jpeg. However, all # requests to the /images/ directory will be handled by # Configuration C.     [ configuration D ] }

Example requests:


 * / -> configuration A
 * /documents/document.html -> configuration B
 * /images/1.gif -> configuration C
 * /documents/1.jpg -> configuration D

Note that you could define these 4 configurations in any order and the results would remain the same. While nested locations are allowed by the configuration file parser, their use is discouraged and may produce unexpected results.

How nginx Determines Which Path Matches
Most users will not need to know how nginx internally determines which path to use - know that it will choose the "most specific" match for your URI in a speedy and efficient manner. For those that are curious, however, read on.

All path strings are sorted alphabetically. nginx then proceeds to search down the list looking for matches until the request URI has a "higher" value then the current string in the sorted list. This is determined using the family of  functions - once   returns 1, then searching stops. Once searching stops, the last string which matched is used.

For example, lets say we have the following paths:

/ /a /apple /banana

Now, lets say the server gets the path "/az". nginx would begin search down this list. First, "/" would match, but "/ is less than "/az" so searching continues. "/a" also matches, but "/a" is still less than "/az" so we continue again. "/apple" does not match. The next string, "/banana", is greater than "/az" so searching stops and the last match, "/a", would be used.

log_not_found
syntax: log_not_found [on|off]

default: log_not_found on

context: http, server, location

The directive enables or disables messages in error_log about files not found on disk.

msie_padding
syntax: msie_padding [on|off] 

default: msie_padding on

context: http, server, location

This directive enables or disables the the msie_padding feature for MSIE browsers. When this is enabled nginx will pad the size of the response headers up to 512 bytes for responses with status codes of more than 400. This prevents activating the "friendly" http error pages feature of the relevant browsers, so as to not hide the possibly more informative error pages.

msie_refresh
syntax: msie_refresh [on|off] 

default: msie_refresh off

context: http, server, location

This directive allows or forbids issuing a  instead of doing a   for MSIE.

optimize_server_names
syntax: optimize_server_names [ on|off ] 

default: optimize_server_names on

context: http, server

Directive activates or deactivates optimization of host name checks for name-based virtual servers.

In particular, the check influences the name of the host used in redirects. If optimization is on, and all name-based servers listening on one address:port pair have identical configuration, then names are not checked during request execution and redirects use first server name.

If redirect must use host name passed by the client, then the optimization must be turned off.

Note: this directive is deprecated in nginx 0.7.x, use server_name_in_redirect instead.

port_in_redirect
syntax: port_in_redirect [ on|off ] 

default: port_in_redirect on

context: http, server, location

Directive allows or prevents port indication in redirects handled by nginx.

If  is on, then Nginx will not add the port in the url when the request is redirected.

recursive_error_pages
syntax: recursive_error_pages [on|off] 

default: recursive_error_pages off

context: http, server, location

enables or disables following a chain of  directives.

root
syntax: root path

default: root html

context: http, server, location, if in location

root specifies the document root for the requests. For example, with this configuration

location /i/ { root /spool/w3; } A request for "/i/top.gif" will return the file "/spool/w3/i/top.gif". You can use variables in the argument.

note: Keep in mind that the root will still append the directory to the request so that a request for "/i/top.gif" will not look in "/spool/w3/top.gif" like might happen in an Apache-like alias configuration where the location match itself is dropped. Use the  directive to achieve the Apache-like functionality.

satisfy_any
syntax: satisfy_any [ on|off ] 

default: satisfy_any off

context: location

Directive solves access with at least one successful checking, executed by modules NginxHttpAccessModule or NginxHttpAuthBasicModule:

location / { satisfy_any on; allow 192.168.1.0/32; deny  all; auth_basic           "closed site"; auth_basic_user_file conf/htpasswd; }

send_timeout
syntax: send_timeout the time

default: send_timeout 60

context: http, server, location

Directive assigns response timeout to client. Timeout is established not on entire transfer of answer, but only between two operations of reading, if after this time client will take nothing, then nginx is shutting down the connection.

sendfile
syntax: sendfile [ on|off ] 

default: sendfile off

context: http, server, location

Directive activate or deactivate the usage of.

server
syntax: server {...}

default: no

context: http

Directive assigns configuration for the virtual server.

There is no separation of IP and name-based (the  header of the request) servers.

Instead, the directive  is used to describe all addresses and ports on which incoming connections can occur, and in directive   indicate all names of the server.

server_name
syntax: ''server_name name [... ] ''

default: server_name hostname

context: server

This directive performs two actions:


 * Compares the  header of the incoming HTTP request against the server { ... } blocks in the Nginx configuration files and selects the first one that matches. This is how virtual servers are defined. Server names are processed in the following order:


 * 1) full, static names
 * 2) names with a wildcard at the start of the name — *.example.com
 * 3) names with a wildcard at the end of the name — www.example.*
 * 4) names with regular expressions
 * If there is no match, a [#server server { ... }] block in the configuration file will be used based on the following order:


 * 1) the server block with a matching   directive marked as
 * 2) the first server block with a matching   directive (or implicit  )


 * Sets the server name that will be used in HTTP redirects if server_name_in_redirect is set.

Example:

server { server_name  example.com  www.example.com; }

The first name becomes the basic name of server. By default the name of the machine (hostname) is used.

Two of the above given names can be combined into one:

server { server_name .example.com; }

It is possible to use "*" for replacing the first or the last part of the name:

server { server_name  example.com  *.example.com  www.example.*; }

It is also possible to use regular expressions in server names, prepending the name with a tilde "~" like so:

server { server_name  www.example.com   ~^www\d+\.example\.com$; }

The basic name of server is used in an HTTP redirects, if no  header was in client request or that header does not match any assigned server_name. You can also use just "*" to force Nginx to use the  header in the HTTP redirect (note that "*" cannot be used as the first name, but you can use a dummy name such as "_" instead):

server { server_name example.com *; } server { server_name _ *; }

Note that this has changed in 0.6.x and is now: server { server_name _; }

Since nginx 0.7.12, an empty server name is supported, to catch the requests without "Host" header: server { server_name ""; }

server_name_in_redirect
syntax: server_name_in_redirect on|off

default: server_name_in_redirect on

context: http, server, location

If  is on, then Nginx will use the first value of the server_name directive for redirects. If  is off, then nginx will use the requested  header.

server_names_hash_max_size
syntax: server_names_hash_max_size number

default: server_names_hash_max_size 512

context: http

The maximum size of the server name hash tables. For more detail see the description of tuning the hash tables in Nginx Optimizations.

server_names_hash_bucket_size
syntax: server_names_hash_bucket_size number

default: server_names_hash_bucket_size 32/64/128

context: http

Directive assigns the size of basket in the hash-tables of the names of servers. This value by default depends on the size of the line of processor cache. For more detail see the description of tuning the hash tables in Nginx Optimizations.

server_tokens
syntax: server_tokens on|off

default: server_tokens on

context: http, server, location

Whether to send the Nginx version number in error pages and  header.

tcp_nodelay
syntax: tcp_nodelay [on|off] 

default: tcp_nodelay on

context: http, server, location

This directive allows or forbids the use of the socket option. Only included in  connections.

You can read more about the  socket option here.

tcp_nopush
syntax: tcp_nopush [on|off] 

default: tcp_nopush off

context: http, server, location

This directive permits or forbids the use of the socket options  on FreeBSD or   on Linux. This option is only available when using.
 * Setting this option causes nginx to attempt to send it's HTTP response headers in one packet on Linux and FreeBSD 4.x


 * ReadMoreAboutTcpNopush

try_files
syntax: ''try_files file1 [file2 ... filen] fallback''

default: none

context: location

This directive tells Nginx to test for each file's existence, and use the first found file as the URI. If none of the files are found, then the location  is called ("fallback" can be any name). is a required parameter. It can be a named location or any guaranteed URI.

Example: location / { try_files index.html index.htm @fallback; }

location @fallback { root /var/www/error; index index.html; }

types
syntax: types {...}

context: http, server, location

Directive assigns the correspondence of expansion and MIME-types of answers. To one MIME- type can correspond several expansions. By default it is used these correspondences:

types { text/html   html; image/gif   gif; image/jpeg  jpg; } The sufficiently complete table of mappings is included and is located in the file.

So that for that determined location's for all answers would reveal MIME- type, it is possible to use the following:

location /download/ { types        { } default_type application/octet-stream; }

= Variables = The core module supports built-in variables, whose names correspond with the names of variables in Apache.

First of all, there are the variables, which represent the lines of the title of the client request, for example,,  , and so forth.

Furthermore, there are other variables:

$arg_PARAMETER
This variable contains the value of the  request variable PARAMETER if present in the query string

$args
This variable is equal to arguments in the line of request;

$binary_remote_addr
The address of the client in binary form;

$body_bytes_sent
(undocumented)

$content_length
This variable is equal to line  in the header of request;

$content_type
This variable is equal to line  in the header of request;

$cookie_COOKIE
The value of the cookie COOKIE;

$document_root
This variable is equal to the value of directive root for the current request;

$document_uri
The same as $uri.

$host
This variable is equal to line  in the header of request or name of the server processing the request if the   header is not available.

$http_HEADER
HTTP header 里边 特定HEADER的值,变量会转成小写,比如 $http_user_agent, $http_referer... header信息 "YOUR-STRANGE-HEADER: values" 能通过 $http_your_strange_header获得.

$is_args
Evaluates to "?" if $args is set, "" otherwise.

$limit_rate
This variable allows limiting the connection rate.

$query_string
The same as $args.

$remote_addr
The address of the client.

$remote_port
The port of the client;

$remote_user
This variable is equal to the name of user, authenticated by the Auth Basic Module;

$request_filename
This variable is equal to path to the file for the current request, formed from directives root or alias and URI request;

$request_body_file
Client request body temporary filename;

$request_completion
(undocumented)

$request_method
This variable is equal to the method of request, usually  or.

$request_uri
This variable is equal to the complete initial URI together with the arguments;

$scheme
The HTTP scheme (i.e. http, https). Evaluated only on demand, for example: rewrite ^(.+)$  $scheme://example.com$1  redirect;

$server_addr
Equal to the server address. As a rule, for obtaining the value of this variable is done one system call. In order to avoid system call, it is necessary to indicate addresses in directives listen and to use parameter.

$server_name
The name of the server.

$server_port
This variable is equal to the port of the server, to which the request arrived;

$server_protocol
This variable is equal to the protocol of request, usually this  or.

$uri
This variable is equal to current URI in the request, it can differ from initial, for example by internal redirects, or with the use of index it is file with internal redirects.

= References = Original Documentation