该模块的功能：颁发cookie 配置示例： 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"'; 指令名称：userid 默认为off on: 启用版本2 v1： 启用版本1 log： 不发送cookies，但是记录进入的cookies off： 不发送cookies，也不记录到日志 指令名称：userid_domain 功能：向指定的域颁发cookie 默认为none 指令名称： userid_expires 功能：为cookie设置生存期 默认为：none 指令名称： userid_name 功能：设置cookie的名字 默认为uid 指令名称：userid_path 功能： 设置cookie的路径 默认为：/ 案例1:   变量： 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.