nginx在配置文件nginx.conf中可以使用很多内置变量，配置如下：
location /info {
add_header 'Content-Type' 'text/html';
echo "http_user_agent :$http_user_agent <br>";
echo "http_cookie :$http_cookie <br>";
echo "http_user_agent :$http_user_agent <br>";
echo "http_cookie :$http_cookie <br>";
echo "arg_name :$arg_name <br>";
echo "args :$args <br>";
echo "binary_remote_addr :$binary_remote_addr <br>";
echo "body_bytes_sent :$body_bytes_sent <br>";
echo "bytes_sent :$bytes_sent <br>";
echo "connection :$connection <br>";
echo "connection_requests :$connection_requests <br>";
echo "content_length :$content_length <br>";
echo "content_type :$content_type <br>";
echo "cookie_name :$cookie_name <br>";
echo "document_root :$document_root <br>";
echo "document_uri :$document_uri <br>";
echo "uri :$uri <br>";
echo "host :$host <br>";
echo "hostname :$hostname <br>";
echo "http_name :$http_name <br>";
echo "https :$https <br>";
echo "is_args :$is_args <br>";
echo "limit_rate :$limit_rate <br>";
echo "msec :$msec <br>";
echo "nginx_version :$nginx_version <br>";
echo "pid :$pid <br>";
echo "pipe :$pipe <br>";
echo "proxy_protocol_addr :$proxy_protocol_addr <br>";
echo "query_string :$query_string <br>";
echo "realpath_root :$realpath_root <br>";
echo "remote_addr :$remote_addr <br>";
echo "remote_port :$remote_port <br>";
echo "remote_user :$remote_user <br>";
echo "request :$request <br>";
echo "request_body :$request_body <br>";
echo "request_body_file :$request_body_file <br>";
echo "request_completion :$request_completion <br>";
echo "request_filename :$request_filename <br>";
echo "request_length :$request_length <br>";
echo "request_method :$request_method <br>";
echo "request_time :$request_time <br>";
echo "request_uri :$request_uri <br>";
echo "scheme :$scheme <br>";
echo "sent_http_name :$sent_http_name <br>";
echo "server_addr :$server_addr <br>";
echo "server_name :$server_name <br>";
echo "server_port :$server_port <br>";
echo "server_protocol :$server_protocol <br>";
echo "status :$status <br>";
echo "tcpinfo_rtt :$tcpinfo_rtt <br>";
echo "tcpinfo_rttvar :$tcpinfo_rttvar <br>";
echo "tcpinfo_snd_cwnd :$tcpinfo_snd_cwnd <br>";
echo "tcpinfo_rcv_space :$tcpinfo_rcv_space <br>";
echo "tcpinfo_rtt :$tcpinfo_rtt <br>";
echo "tcpinfo_rttvar :$tcpinfo_rttvar <br>";
echo "tcpinfo_snd_cwnd :$tcpinfo_snd_cwnd <br>";
echo "tcpinfo_rcv_space :$tcpinfo_rcv_space <br>";
echo "tcpinfo_rtt :$tcpinfo_rtt <br>";
echo "tcpinfo_rttvar :$tcpinfo_rttvar <br>";
echo "tcpinfo_snd_cwnd :$tcpinfo_snd_cwnd <br>";
echo "tcpinfo_rcv_space :$tcpinfo_rcv_space <br>";
echo "tcpinfo_rtt :$tcpinfo_rtt <br>";
echo "tcpinfo_rttvar :$tcpinfo_rttvar <br>";
echo "tcpinfo_snd_cwnd :$tcpinfo_snd_cwnd <br>";
echo "tcpinfo_rcv_space :$tcpinfo_rcv_space <br>";
echo "time_iso8601 :$time_iso8601 <br>";
echo "time_local :$time_local <br>";
echo "uri :$uri <br>";
}
测试结果如下：
http://127.0.0.1/info?a=1&b=2
http_user_agent :Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/38.0.2125.104 Safari/537.36 http_user_agent :Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/38.0.2125.104 Safari/537.36 arg_name : args :a=1&b=2 binary_remote_addr :�w� body_bytes_sent :0 bytes_sent :0 connection :6 connection_requests :2 content_length : content_type : cookie_name : document_root :/opt/openresty/nginx/html document_uri :/info uri :/info http_name : https : is_args :? limit_rate :0 msec :1450346470.512 nginx_version :1.9.3 pid :8161 pipe :. proxy_protocol_addr : query_string :a=1&b=2 realpath_root :/opt/openresty/nginx/html remote_addr :127.0.0.1 remote_port :57621 remote_user : request :GET /info?a=1&b=2 HTTP/1.1 request_body : request_body_file : request_completion : request_filename :/opt/openresty/nginx/html/info request_length :391 request_method :GET request_time :0.000 request_uri :/info?a=1&b=2 scheme :http sent_http_name : server_addr :127.0.0.1 server_name :localhost server_port :80 server_protocol :HTTP/1.1 status :200 tcpinfo_rtt :73750 tcpinfo_rttvar :99500 tcpinfo_snd_cwnd :10 tcpinfo_rcv_space :14480 tcpinfo_rtt :73750 tcpinfo_rttvar :99500 tcpinfo_snd_cwnd :10 tcpinfo_rcv_space :14480 tcpinfo_rtt :73750 tcpinfo_rttvar :99500 tcpinfo_snd_cwnd :10 tcpinfo_rcv_space :14480 tcpinfo_rtt :73750 tcpinfo_rttvar :99500 tcpinfo_snd_cwnd :10 tcpinfo_rcv_space :14480 time_iso8601 :2015-12-17T18:01:10+08:00 time_local :17/Dec/2015:18:01:10 +0800 uri :/info
参考：
http://www.cnphp.info/nginx-embedded-variables-lasted-version.html
https://openresty.org/download/agentzh-nginx-tutorials-zhcn.html