Re: How to print request headers before and after processing (Apache Users)

Hi Rainer,

thanks for the enlightenment :-) I was not aware, that the RewriteRule check is done before actually evaluating the RewriteCond(s). So, out of curiosity I gave it a try. As I only need to look for the GET request on the login-page, this works fine for me:

RewriteCond "%{REQUEST_METHOD}" "GET"
RewriteRule ^/xxx/facelets/logon.xhtml$ - [E=login_jsid:%{HTTP_COOKIE}]

Surprisingly, here I can use a variable in the assignment to "login_jsid" :-) Otherwise, this would have worked as well:

RewriteCond "%{REQUEST_METHOD}" "GET"
RewriteCond "%{HTTP_COOKIE}" "(.*)"
RewriteRule ^/xxx/facelets/logon.xhtml$ - [E=login_jsid:%1]

Clearly, the logging is now much better than with the "forensic" stuff. Now to the main task :-)

Cheers

Martin

On Thu, Mar 22, 2018 at 8:28 PM, Rainer Jung <rainer.jung@xxxxxxxxxxx> wrote:

Am 22.03.2018 um 18:56 schrieb Martin Knoblauch:

Hi Rainer,

  unfortunately mod_log_debug seems to work only on directory scope, not on virtual host.

But note, that <Location> is directory scope, for instance

<Location /cb2/facelets/logon.xhtml>
...
</Location>

And I considered the mod_rewrite thingy, but feared it to be to expensive.

>

  In the meantime I found "mod_log_forensic". Ugly, I do not know the cost, but it works for my purpose.

I think mod_rewrite is not that expensive.

When a RewriteCond and a RewriteRuke is combined, it will first check the left side of the RewriteRule against your URL. If it doesnt match, the RewriteCond and the flags are not evaluated. So it is important to not have a complex pattern in RewriteRule. In your case it is not complex.

Then next te RewriteCond is checked. In your case picking one header and matching with ".*" which is also not very expensive (not backtracking).

And then finally the env var setting. Performancewise this will be very close to the SetEnvIf variant.

Regards,

Rainer

Thanks
Martin

On Thu, Mar 22, 2018 at 6:16 PM, Rainer Jung <rainer.jung@xxxxxxxxxxx <mailto:rainer.jung@kippdata.de>> wrote:

Am 22.03.2018 um 18:08 schrieb Eric Covener:

On Thu, Mar 22, 2018 at 1:03 PM, Martin Knoblauch
<knobi@xxxxxxxxxxxx <mailto:knobi@xxxxxxxxxxxx>> wrote:

Hi Eric,

   thanks, but does not work.

login_jsid=Cookie prints "Cookie"
login_jsid=%{Cookie} prints "%{Cookie}"

Apparently the right sides of the assignment are just taken
as literals
without evaluating them as variables.

Arg, sorry, It is only for the first arg.

Had a brief look at mod_log_debug, but do not see how it
helps me in this
case.

You could log expressions before/after the your edits.

... by choosing different hooks.

If that does not work, you could also try to copy the header to an
env var using mod_rewrite. Something like

RewriteCond "%{HTTP_COOKIE}" "(.*)"
RewriteRule ^/cb2/facelets/logon.xhtml$ - [E=login_jsid:%1]

But you need to test. Not sure in what order the mod_headers
replacement and the mod_rewrite rule handling run. I vaguely
remember having used a trick like this.

Including your marker login_get should work like this:

RewriteCond "%{HTTP_COOKIE}" "(.*)"
RewriteRule ^/cb2/facelets/logon.xhtml$ - [E=login_jsid:%1,E=login_get]

Regards,

Rainer

---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
<mailto:users-unsubscribe@httpd.apache.org>
For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
<mailto:users-help@httpd.apache.org>

--
------------------------------------------------------
Martin Knoblauch
email: k n o b i AT knobisoft DOT de
www: http://www.knobisoft.de

---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx

------------------------------------------------------
Martin Knoblauch
email: k n o b i AT knobisoft DOT de
www: http://www.knobisoft.de