Recently, during a side project I had to fix logging in Apache for Both Access Logs and Error Logs; Fortunately since Apache 2.4 you can also specify the ErrorLogFormat of your logs. The problem was that the client had clients with some over Cloudflare -> Varnish -> Apache and some over Varnish -> Apache and I needed to determine how to catch both and log properly.
The solution was as follows:
- Catch the Cloudflare and Varnish Headers and set the X-Forwarded-For header in the varnish configuration
remove req.http.X-Forwarded-For;
set req.http.X-Forwarded-For = client.ip;
if ( req.http.CF-Connecting-IP ) {
remove req.http.X-Forwarded-For;
set req.http.X-Forwarded-For = req.http.CF-Connecting-IP;
}
- Setup the Apache LogFormat to use this header
LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b" varnishcommon
- Setup the ErrorLogFormat to use this header
ErrorLogFormat "[%t] [%l] [pid %P] %F: %E: [%{c}a] %M"
-
Setup the Apache vhosts to use the varnishcommon CustomLog
-
Restart Apache
service httpd restart