If we change Nginx log format by following the instruction, httpd section of Logwatch doesn't work.
To solve this problem, we can change setting of Logwatch, however, I think it's much better that no such change/modification is required.

Do you have a specific reason for the suggested format?

If no, I'd recommend that the log format is combined+request_time:

'$remote_addr - $remote_user [$time_local] '
'"$request" $status $body_bytes_sent '
'"$http_referer" "$http_user_agent" '
'$request_time';

, which is OK with Logwatch at least my server.
If you can accept this, I can make PR of the corresponding code.

Hi, I am trying to use this plugin on Debian Jessie.
Here, CPAN perl libs are to be installed by apt-get command:
# apt-get install libstatistics-basic-perl libstatistics-descriptive-perl libfile-readbackwards-perl libstatistics-lite-perl/sid
Then, the following test-run returns the error
# munin-run nginx_request_time

Name "main::bw" used only once: possible typo at /etc/munin/plugins/nginx_request_time_max line 101.
Can't call method "readline" on an undefined value at /etc/munin/plugins/nginx_request_time_max line 101.

The versions of each libs are
libstatistics-basic-perl: Version: 1.6607-1
libstatistics-descriptive-perl: Version: 3.0607-1
libfile-readbackwards-perl: Version: 1.05-1
libstatistics-lite-perl: Version: 3.62-1

Any advice would be appreciated, thx!
(The reply in Japanese language is also OK for me.)