A friend was struggling with this on their installation. They’d forgotten (and not written down) their install directory for WordPress.
Here are two simple ways to find your WordPress directory and to find its wp-config.php file:
That will show all of the WordPress sites installed for Apache, if your server is using the default www tree.
Or, you can look at your Apache configuration:
ls -alst *.conf
0000-tweets.conf 0006-wholesomevegan.conf 001-medium.conf publishingwithwordpress.conf
sudo more 001-medium.conf
It will look something like this:
Allow from all
The answer is here:
In this case, you can find the wp-config.php file in that directory:
ls -alst /var/www/pwp
4 -rw-r--r-- 1 www-data www-data 3485 Jul 15 2014 wp-config.php
I also suggest you go back to your production server installation notes which should document which directory you installed wordpress in.
Hope this helps!