ERROR 2002 (HY000) Can't connect to local Mysql server through socket '/var/run/mysqld/mysqld.sock' (2)

I have Ubuntu host 18.04.
Installed docker and created a ubuntu bionic container.
Insider this container I followed all instructions as per the installation page for Ubuntu bionic.
I ran OpenProject configure and followed the wizard and chose to install Mysql.
The above is the error I get at last.

Can anyone help here?