Piwik and NGinx in an environment with Drupal/Magento/WP etc


I installed a server with several apps on it (Magento/Drupal/WordPress) and now I’d like to have their statistics there as well.
With Apache that worked out with just a new virtual host - now with NGinX things seem to be more difficult.
I’ve seen: GitHub - perusio/piwik-nginx: Nginx configuration for running Piwik
But I already use the config for Drupal and with a few complications got Magento and WordPress working.
The Piwik config seems to be so complex, that I don’t dare to start with it or try to integrate it.
I can access Piwik to check the statistics. But it seems as if my websites can’t access the tracker - I don’t receive any data anymore since I moved Piwik to the new server (3 days ago).
What should I do now? Is there one file with all neccesary settings that I can use for my nginx piwik virtual host?
Or can anybody guess what’s the problem? (in my browser it seems like a timeout if I access the WP site while it’s trying to load the statistics URL).

Thanks in advance