We have apache webserver as "entry" for incoming traffic it then delegates to tomcats with mod_jk.
We want to log the HTTP digest username, sample header:
Authorization: Digest username="Mufasa", realm="email@example.com", nonce="dcd98b7102dd2f0e8b11d0f600bfb0c093", ...
Unfortunately using the '%u' doesn't work as described. My guess is as we authenticate on tomcat side (apache delegates calls to tomcat with mod_jk) the own logging facility of apache doesn't know how to access the digest-username (because own auth module is bypassed).
To workaround this: Is there a custom log-format expression with regex matching for, e.g. telling to extract username="(.*?)" from 'Authorization' header and push to logs?