At 23:27 09/08/02, Joshua Slive wrote:
>Alan Skea wrote:
>>I got a bit frustrated by the lack of flexibility in the mod_log_config CustomLog
>directive. What I wanted was to make logging conditional on multiple environment
>variables that get set by different modules, and also to be able to make logging
>behaviour depend on the value of the variables rather than just their presence or
>absence.
>>I decide that the appropriate way to do this was to extend the syntax of the
>CustomLog directive as follows:
>
>I don't believe this is necessary. You didn't present a specific use case, but let
>me try an example:
>
>Log only if var1 is set to yes and var2 is not set to no:
>
>SetEnvIf var1 yes logme
>SetEnvIf var2 no !logme
>CustomLog logs/access_log combined env=logme
>
>If that doesn't solve your problem, please be more specific about what the problem is.
>
>Joshua.
I don't think SetEnvIf quite does it. In one module I extract a session tracking
token from the URI and set it into an env var. If this var is present then I want to
use a particular log format. I also started looking at a module called robotcop the
other day. It monitors accesses to the robots.txt file to determine if a request
comes from a robot. Without getting into the merit or demerits of a stateful module I
was trying out logging the robot requests to a completely different logfile. In
addition there are a number of states that robotcop can be in that might also affect
how (or if) I would want to log the request.
So the upshot is that I have two modules that set env variables and at least four
different behaviours depending on the values of those variables. Here's what I want
to achieve using the syntax I proposed:
CustomLog logs/robotlog session_fmt env=SESSION,ROBOTCOP
CustomLog logs/userlog session_fmt env=SESSION,!ROBOTCOP
CustomLog logs/robotlog combined env=!SESSION,ROBOTCOP
CustomLog logs/userlog combined env=!SESSION,!ROBOTCOP
There was a moment that I considered further qualifying the robotcop logging based on
other internal robotcop state. This would mean setting different env vars for each
different logging behaviour, or getting the logging mechanism to do at least allow
exact matching on the value of an env var. Anyway that idea went out the window for
now - at least till I've decided if robotcop is really something I want to use,
however the point is it would have further complicated the logging setup. It seems to
me that the right place to conjunct env vars for logging is in the logging directives
without some place where different env vars can be tested within the same directive,
the above isn't possible.
-_-_ Alan.
