Module ngx_http_userid_module

Example Configuration
Directives
     userid
     userid_domain
     userid_expires
     userid_flags
     userid_mark
     userid_name
     userid_p3p
     userid_path
     userid_service
Embedded Variables

The ngx_http_userid_module module sets cookies suitable for client identification. Received and set cookies can be logged using the embedded variables $uid_got and $uid_set. This module is compatible with the mod_uid module for Apache.

Example Configuration

userid         on;
userid_name    uid;
userid_domain  example.com;
userid_path    /;
userid_expires 365d;
userid_p3p     'policyref="/w3c/p3p.xml", CP="CUR ADM OUR NOR STA NID"';

Directives

Syntax: userid on | v1 | log | off;
Default: 
userid off;
Context: http, server, location

Enables or disables setting cookies and logging the received cookies:

on
enables the setting of version 2 cookies and logging of the received cookies;
v1
enables the setting of version 1 cookies and logging of the received cookies;
log
disables the setting of cookies, but enables logging of the received cookies;
off
disables the setting of cookies and logging of the received cookies.

Syntax: userid_domain name | none;
Default: 
userid_domain none;
Context: http, server, location

Defines a domain for which the cookie is set. The none parameter disables setting of a domain for the cookie.

Syntax: userid_expires time | max | off;
Default: 
userid_expires off;
Context: http, server, location

Sets a time during which a browser should keep the cookie. The parameter max will cause the cookie to expire on “31 Dec 2037 23:55:55 GMT”. The parameter off will cause the cookie to expire at the end of a browser session.

Syntax: userid_flags off | flag ...;
Default: 
userid_flags off;
Context: http, server, location

This directive appeared in version 1.19.3.

If the parameter is not off, defines one or more additional flags for the cookie: secure, httponly, samesite=strict, samesite=lax, samesite=none.

Syntax: userid_mark letter | digit | = | off;
Default: 
userid_mark off;
Context: http, server, location

If the parameter is not off, enables the cookie marking mechanism and sets the character used as a mark. This mechanism is used to add or change userid_p3p and/or a cookie expiration time while preserving the client identifier. A mark can be any letter of the English alphabet (case-sensitive), digit, or the “=” character.

If the mark is set, it is compared with the first padding symbol in the base64 representation of the client identifier passed in a cookie. If they do not match, the cookie is resent with the specified mark, expiration time, and “P3P” header.

Syntax: userid_name name;
Default: 
userid_name uid;
Context: http, server, location

Sets the cookie name.

Syntax: userid_p3p string | none;
Default: 
userid_p3p none;
Context: http, server, location

Sets a value for the “P3P” header field that will be sent along with the cookie. If the directive is set to the special value none, the “P3P” header will not be sent in a response.

Syntax: userid_path path;
Default: 
userid_path /;
Context: http, server, location

Defines a path for which the cookie is set.

Syntax: userid_service number;
Default: 
userid_service IP address of the server;
Context: http, server, location

If identifiers are issued by multiple servers (services), each service should be assigned its own number to ensure that client identifiers are unique. For version 1 cookies, the default value is zero. For version 2 cookies, the default value is the number composed from the last four octets of the server’s IP address.

Embedded Variables

The ngx_http_userid_module module supports the following embedded variables:

$uid_got
The cookie name and received client identifier.
$uid_reset
If the variable is set to a non-empty string that is not “0”, the client identifiers are reset. The special value “log” additionally leads to the output of messages about the reset identifiers to the error_log.
$uid_set
The cookie name and sent client identifier.