指定log_format:
log_format main '[$request_time] $remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';需要修改server中log_format才能生效：
server {
listen 80;
server_name localhost;
access_log logs/localhost.log main;
#...
}
