Question

i would like to set up conditional logging for requests done over apaches mod_proxy. is that possible and if so how?

i already checked the documentation but did not find anything that i could use for setenvif

i ask here and not on serverfault because there is a business application logic behind (traffic calcluations for users…)

also i noticed that that proxy usernames in the log file.

proxy.2x.to:80 62.178.15.161 - peidel [06/Jun/2011:01:31:44 +0200] "GET http://proxy.2x.to/ HTTP/1.1" 200 1339 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:2.0.1) Gecko/20100101 Firefox/4.0.1" 

this is line from /var/log/apache2/other_vhosts_access.log which is generated by the default log defnitions:

LogFormat "%v:%p %h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined
CustomLog /var/log/apache2/other_vhosts_access.log vhost_combined

peidel is the username.

in the documentation it says:

%l Remote logname (from identd, if
supplied). This will return a dash
unless mod_ident is present and
IdentityCheck is set On.

now my question on this: can i rely on that? or is it possible that someone produces request with this identity information but who is not authenticated and produces log lines with an identity anyway?

Answer 1

http://httpd.apache.org/docs/current/logs.html

This is the userid of the person
requesting the document as determined
by HTTP authentication. The same value
is typically provided to CGI scripts
in the REMOTE_USER environment
variable. If the status code for the
request (see below) is 401, then this
value should not be trusted because
the user is not yet authenticated. If
the document is not password
protected, this part will be “-” just
like the previous one.