Best way to log POST data in Apache?

Question

Imagine you have a site API that accepts data in the form of GET requests with parameters, or as POST requests (say, with standard url-encoded, &-separated POST data). If you want to log and analyze API calls, the GET requests will be easy, because they will be in the apache log. Is there a simple way to get the POST data in the apache log as well?

(Of course we could log the POST data explicitly in the application, but I'd like to have an configuration-level way that let me not worry about it in code.)

Answer 1

I would do it in the application, actually. It's still configurable at runtime, depending on your logger system, of course. For example, if you use Apache Log (log4j/cxx) you could configure a dedicated logger for such URLs and then configure it at runtime from an XML file.

Answer 2

Not exactly an answer, but I have never heard of a way to do this in Apache itself. I guess it might be possible with an extension module, but I don't know whether one has been written.

One concern is that POST data can be pretty large, and if you don't put some kind of limit on how much is being logged, you might run out of disk space after a while. It's a possible route for hackers to mess with your server.

Answer 3

Use Apache's mod_dumpio. Be careful for obvious reasons.