Update to the ticket, it does work when I connect using IP address (127.0.0.1) but when name (localhost) is used, I checked my /etc/hosts and it has 127.0.0.1 set as localhost, also my firewall is disabled.

Sorry, but your problem does not imply a bug in PHP itself.  For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system is not the
appropriate forum for asking support questions.  Due to the volume
of reports we can not explain in detail here why your report is not
a bug.  The support channels will be able to provide an explanation
for you.

Thank you for your interest in PHP.

Specifying "localhost" as the hostname will try to use a socket file. Your MySQL server may not have created one.

I just re-configured my mysql to create the mysql.sock at /tmp/mysql.sock and edited php.ini to read mysql.default_socket where the mysql.sock is and it still won't connect using name (localhost), I can see the newly created mysql.sock file in /tmp, but PHP 7.0.4 seems not to be able to locate it, any other ideas?

Thanks.

This is weird, if I run:

php mysqltest.php

it works, but if I do it via web it says it cannot find the file, any ideas?

This isn't really the best place for general help. Try a mailing list or online forum.
http://php.net/support.php

More info:

I just created a script to test socket access to /tmp/mysql.sock and it tested successfully, so if PHP can open a socket file in the place where it's supposed to be, why can't it open it using mysqli_connect("localhost", "user", "password", "database");

Thanks.