Since MySQL 5.7 changed the security model, now the MySQL root login requires a sudo, which cannot be done through the web browser. The workaround is to create a new user and grant it permission.

CREATE USER 'phpmyadmin'@'localhost' IDENTIFIED BY 'some_pass';
GRANT ALL PRIVILEGES ON *.* TO 'phpmyadmin'@'localhost' WITH GRANT OPTION;
FLUSH PRIVILEGES;

Allow remote connections:


CREATE USER 'phpmyadmin'@'%' IDENTIFIED BY 'some_pass';
GRANT ALL PRIVILEGES ON *.* TO 'phpmyadmin'@'%' WITH GRANT OPTION;
FLUSH PRIVILEGES;