相关知识可参考文章：
1.查看nginx的log配置
1）vim /etc/nginx/nginx.conf
打开为
user nginx;
worker_processes 1;error_log /var/log/nginx/error.log warn; //记录nginx错误日志的路径， WARN代表错误日志的级别
pid /var/run/nginx.pid; events { worker_connections 1024;} http { include /etc/nginx/mime.types; default_type application/octet-stream;log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"';access_log /var/log/nginx/access.log main; // main代表nginx的log_format的name
sendfile on;
#tcp_nopush on;keepalive_timeout 65;
#gzip on;
include /etc/nginx/conf.d/*.conf;
}针对其中log_format
1.$remote_addr 与$http_x_forwarded_for 用以记录客户端的ip地址；
2.$remote_user ：用来记录客户端用户名称； 3.$time_local ： 用来记录访问时间与时区； 4.$request ： 用来记录请求的url与http协议； 5.$status ： 用来记录请求状态；成功是200， 6.$body_bytes_s ent ：记录发送给客户端文件主体内容大小； 7.$http_referer ：用来记录从那个页面链接访问过来的； 8.$http_user_agent ：记录客户端浏览器的相关信息；2）.将 1）中的 error.log打印出来的标准格式
tail -f /var/log/nginx/error.log
2017/10/11 14:01:36 [error] 1337#1337: *1 open() "/usr/share/nginx/html/favicon.ico" failed (2: No such file or directory), client: 192.168.2.113, server: localhost, request: "GET /favicon.ico HTTP/1.1", host: "192.168.2.157", referrer: "http://192.168.2.157/"
2017/10/11 14:16:05 [error] 1337#1337: *3 open() "/usr/share/nginx/html/1111" failed (2: No such file or directory), client: 192.168.2.113, server: localhost, request: "GET /1111 HTTP/1.1", host: "192.168.2.157"2017/10/11 14:16:26 [error] 1392#1392: *1 open() "/usr/share/nginx/html/1111" failed (2: No such file or directory), client: 192.168.2.113, server: localhost, request: "GET /1111 HTTP/1.1", host: "192.168.2.157"2.nginx变量
1）http请求变量
arg_PARAMETER、http_HEADER、sent_http_HEADER（服务端返回给客户端reponse的head）
例子：
vim /etc/nginx/nginx.conf
修改配置文件
user nginx;
worker_processes 1;error_log /var/log/nginx/error.log warn; //记录nginx错误日志的路径， WARN代表错误日志的级别
pid /var/run/nginx.pid; events { worker_connections 1024;} http { include /etc/nginx/mime.types;default_type application/octet-stream;log_format main '$http_user_agent' '$remote_addr - $remote_user [$time_local] "$request" ' //原始是http-User-Agent 但是这里需要小写，并且将-替换成_
'$status $body_bytes_sent "$http_referer" ''"$http_user_agent" "$http_x_forwarded_for"';access_log /var/log/nginx/access.log main; // main代表nginx的log_format的name
sendfile on;
#tcp_nopush on;keepalive_timeout 65;
#gzip on;
include /etc/nginx/conf.d/*.conf;
}保存后
nginx -t -c /etc/nginx/nginx.conf // -t表示检查配置文件的格式正确与否，-c 标识配置文件的路径的检查
如果成功后
nginx -s reload -c /etc/nginx/nginx.conf //重新加载配置
请求几次本机
curl http://127.0.0.1
tail -n 200 /var/log/nginx/access.log
发现日志最前面出现的相应的信息
2）内置变量
nginx内置的
访问
点击Logging to syslog
点击红框可以查看所有的内置变量
3）自定义变量
自己定义