Nginx Variables

nginxvarcore.md

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

• $body_bytes_sent
  number of bytes sent to a client, not counting the response header; this variable is compatible with the “%B” parameter of the mod_log_config Apache module

• $bytes_sent
  number of bytes sent to a client

• $connection
  connection serial number

$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

$cookie_name 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)

• $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 and fastcgi_pass directives.

• $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 server, passing the request body should be disabled by the proxy_pass_request_body off and fastcgi_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_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

• $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 listen directives 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” or “HTTP/1.1”

$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.

Wish these had examples, little vague.

Although, should be added in NginX documentation.