6. Nginx basic module-Nginx log configuration

1 Nginx log configuration

ELK

	Nginx	Java	json

192.168.104.143 - - [20/Jan/2020:13:58:02 +0800] "GET /%E8%85%BE%E8%AE%AF%E9%A6%96%E9%A1%B5_files/default_b.png HTTP/1.1" 200 10392 "http://192.168.101.82/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36" "-"

Nginx has a very flexible logging mode, each level of configuration can have its own independent access log, and the log format can be customized through the log_format command.

1.1 log_format instruction

#Configuration syntax: include: error.log access.log

Syntax: log_format name [escape=default | json ] string …;

Default: log_format combined “…”;

Context: http

1.2 Default nginx definition syntax

log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                  '$status $body_bytes_sent "$http_referer" '
                  '"$http_user_agent" "$http_x_forwarded_for"';

Variables allowed in nginx log format

• $remote_addr records the client IP address
• $remote_user records the client user name
• $time_local records the universal local time
• $time_iso8601 records the local time in the ISO8601 standard format
• $request records the request method and the requested http protocol
• $status Record the status code of the request (user positioning error information)
• $body_bytes_sent The total number of bytes sent to the client, excluding the size of the response header
• $bytes_sent The total number of bytes sent to the client
• $msec Log writing time, in seconds, precision is milliseconds
• $http_referer records the visits from that page link
• $http_user_agent records client browser related information
• $http_x_forwarded_for records the client ip address
• $request_length The length of the request
• $request_time The time spent in the request, in seconds, with an accuracy of milliseconds

note:

If Nginx is in the load balancer, after nginx reverse proxy, the web server cannot directly obtain the client's real IP address.

$remote_addr gets the ip address of the reverse proxy. The reverse proxy server is forwarding the request http header information

Add x+Forwarded_For information to record the client ip address and the server address requested by the client

1.3 How to use access_log

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;
server {
        listen       80;
        server_name  localhost;
        access_log  logs/host.access.log  main;       //存放日志文件，并调用main日志格式
        location / {
            root   html;
            index  index.html index.htm;
        }
}