wp-now: Error establishing database connection when 'DB_HOST' is 'localhost'

[danielbachhuber]

define( 'DB_HOST', '127.0.0.1' ); works as expected. However, define( 'DB_HOST', 'localhost' ); produces this error:

From WordPress/wordpress-playground#360 (review)

Done is:

• wp-now can connect to a MySQL database on 'localhost'

[adamziel]

Does it work with define( 'DB_HOST', 'localhost:<port>' );? If it's just localhost, PHP will try to use a unix socket (which lives in /var/run/mysqld/mysql.sock by default) instead of connecting over the network. Perhaps mounting /var in the VFS would do the trick?

[danielbachhuber]

Does it work with define( 'DB_HOST', 'localhost:<port>' );?

Nope.

Perhaps mounting /var in the VFS would do the trick?

Should we mount the entirety of /var, or simply /var/run/mysqld/?

[adamziel]

For now the latter will do. Later on we might need access to more unix socket to support other PHP extensions. All of this hinges on Emscripten's ability to communicate through these sockets, though. If it cannot easily do it, we'll need to find a way to always trigger the network mode

It is weird that it doesn't work with the port, though. I wonder if WordPress strips before passing the host string as an argument somehow.