Embedded Variables
The ngx_http_core_module
module supports embedded variables with names matching the Apache Server variables. First of all, these are variables representing client request header fields, such as $http_user_agent
, $http_cookie
, and so on. Also there are other variables:
$arg_
name
- argument
name
in the request line $args
- arguments in the request line
$binary_remote_addr
- client address in a binary form, value’s length is always 4 bytes for IPv4 addresses or 16 bytes for IPv6 addresses
$body_bytes_sent
- number of bytes sent to a client, not counting the response header; this variable is compatible with the “
%B
” parameter of themod_log_config
Apache module $bytes_sent
- number of bytes sent to a client (1.3.8, 1.2.5)
$connection
- connection serial number (1.3.8, 1.2.5)
$connection_requests
- current number of requests made through a connection (1.3.8, 1.2.5)
$content_length
- “Content-Length” request header field
$content_type
- “Content-Type” request header field
- the
name
cookie $document_root
- root or alias directive’s value for the current request
$document_uri
- same as
$uri
$host
- in this order of precedence: host name from the request line, or host name from the “Host” request header field, or the server name matching a request
$hostname
- host name
$http_
name
- arbitrary request header field; the last part of a variable name is the field name converted to lower case with dashes replaced by underscores
$https
- “
on
” if connection operates in SSL mode, or an empty string otherwise $is_args
- “
?
” if a request line has arguments, or an empty string otherwise $limit_rate
- setting this variable enables response rate limiting; see limit_rate
$msec
- current time in seconds with the milliseconds resolution (1.3.9, 1.2.6)
$nginx_version
- nginx version
$pid
- PID of the worker process
$pipe
- “
p
” if request was pipelined, “.
” otherwise (1.3.12, 1.2.7) $proxy_protocol_addr
- client address from the PROXY protocol header, or an empty string otherwise (1.5.12)
The PROXY protocol must be previously enabled by setting the
proxy_protocol
parameter in the listen directive. $proxy_protocol_port
- client port from the PROXY protocol header, or an empty string otherwise (1.11.0)
The PROXY protocol must be previously enabled by setting the
proxy_protocol
parameter in the listen directive. $query_string
- same as
$args
$realpath_root
- an absolute pathname corresponding to the root or alias directive’s value for the current request, with all symbolic links resolved to real paths
$remote_addr
- client address
$remote_port
- client port
$remote_user
- user name supplied with the Basic authentication
$request
- full original request line
$request_body
- request body
The variable’s value is made available in locations processed by the proxy_pass, fastcgi_pass,uwsgi_pass, and scgi_pass directives when the request body was read to a memory buffer.
$request_body_file
- name of a temporary file with the request body
At the end of processing, the file needs to be removed. To always write the request body to a file,client_body_in_file_only needs to be enabled. When the name of a temporary file is passed in a proxied request or in a request to a FastCGI/uwsgi/SCGI server, passing the request body should be disabled by the proxy_pass_request_body off, fastcgi_pass_request_body off,uwsgi_pass_request_body off, or scgi_pass_request_body off directives, respectively.
$request_completion
- “
OK
” if a request has completed, or an empty string otherwise $request_filename
- file path for the current request, based on the root or alias directives, and the request URI
$request_id
- unique request identifier generated from 16 random bytes, in hexadecimal (1.11.0)
$request_length
- request length (including request line, header, and request body) (1.3.12, 1.2.7)
$request_method
- request method, usually “
GET
” or “POST
” $request_time
- request processing time in seconds with a milliseconds resolution (1.3.9, 1.2.6); time elapsed since the first bytes were read from the client
$request_uri
- full original request URI (with arguments)
$scheme
- request scheme, “
http
” or “https
” $sent_http_
name
- arbitrary response header field; the last part of a variable name is the field name converted to lower case with dashes replaced by underscores
$sent_trailer_
name
- arbitrary field sent at the end of the response (1.13.2); the last part of a variable name is the field name converted to lower case with dashes replaced by underscores
$server_addr
- an address of the server which accepted a request
Computing a value of this variable usually requires one system call. To avoid a system call, the listendirectives must specify addresses and use the
bind
parameter. $server_name
- name of the server which accepted a request
$server_port
- port of the server which accepted a request
$server_protocol
- request protocol, usually “
HTTP/1.0
”, “HTTP/1.1
”, or “HTTP/2.0” $status
- response status (1.3.2, 1.2.2)
$tcpinfo_rtt
,$tcpinfo_rttvar
,$tcpinfo_snd_cwnd
,$tcpinfo_rcv_space
- information about the client TCP connection; available on systems that support the
TCP_INFO
socket option $time_iso8601
- local time in the ISO 8601 standard format (1.3.12, 1.2.7)
$time_local
- local time in the Common Log Format (1.3.12, 1.2.7)
$uri
- current URI in request, normalized
The value of
$uri
may change during request processing, e.g. when doing internal redirects, or when using index files.