My installation is purely local on a laptop.
This means web server, mysql (mariadb), and php are all installed locally.
mysql is configured to not use networking, so socket communication is necessary.
the webserver is chrooted so I need to configure the socket in cpg1.6.06 as seen by the webserver
I have already configured phpMyAdmin and WordPress to work this way with no problem
None of the configuration tricks used by those applications work for Coppermine.
I can find no Coppermine documentation that shows how to do this.
help
Just "localhost" doesn't work?
localhost does not work as mysql is configured with NO network access allowed.
Use of 'localhost' with mysqli should open a UNIX socket.
https://www.php.net/manual/en/mysqli.quickstart.connections.php
Yes, but in the wrong location. Re-read OP
Oops! Replied too fast. The link in your post has the answer. Will try and then report the result.
Of course a default socket needs be set in PHP
Success!
edit /etc/php-7.3.ini
find the [MYSQLi] section and change default_host to localhost and default_socket to /your/path/to/mysql.sock
save the file and restart php73_fpm
In the Coppermine installer, blank the host field and enter your database username and password
Of course, this only works if you just have one application that uses the default values.
Fortunately, my other applications let me specify the socket location!