We are currently trying out this Fail2Ban rule on one of our server, to block simple (but very upsetting) DOS attacks on Nginx automatically (after 30 seconds).
New filter in /etc/fail2ban/filter.d/nginx-dos.conf:
# Fail2Ban configuration file # # Generated on Fri Jun 08 12:09:15 EST 2012 by BeezNest # # Author: Yannick Warnier # # $Revision: 1 $ # [Definition] # Option: failregex # Notes.: Regexp to catch a generic call from an IP address. # Values: TEXT # failregex = ^<HOST> -.*"(GET|POST).*HTTP.*"$ # Option: ignoreregex # Notes.: regex to ignore. If this regex matches, the line is ignored. # Values: TEXT # ignoreregex =
In our jail.local, we have (at the end of the file):
[nginx-dos] # Based on apache-badbots but a simple IP check (any IP requesting more than # 240 pages in 60 seconds, or 4p/s average, is suspicious) # Block for two full days. # @author Yannick Warnier enabled = true port = http,8090 filter = nginx-dos logpath = /var/log/nginx/*-access.log findtime = 60 bantime = 172800 maxretry = 240
Of course, in case you would be logging all resources of your site (images, css, js, etc), it would be really easy to get to those numbers as a normal user. To avoid this, use the access_log off directive of Nginx, like so:
# Serve static files directly
location ~* .(png|jpe?g|gif|ico)$ {
expires 1y;
access_log off;
try_files $uri $uri/ @rewrite;
gzip off;
}
location ~* .(mp3)$ {
expires 1y;
access_log off;
gzip off;
}
location ~* .(css)$ {
expires 1d;
access_log off;
}
location ~* .(js)$ {
expires 1h;
access_log off;
}
We’ll see how that works for us… (and report here)
It's only fair to share...
Interested to know how it worked out, do you have any results to report?
hi, for apache how to do it to bypass images, css…? then, i have /var/log/httpd/sb-access_log is that correct to use? OR *access_log at the end is correct? thanks