I found a blog and I followed his instruction and it works !
I'm sharing the solution Referenced Blog
I put these lines in /etc/make.conf:
USE="apache2 mysql php pam ssl xml xml2 berkdb innodb jpeg png"
If you want to install also phpmyadmin, then you should also add pcre session unicode:
USE="apache2 mysql php pam ssl xml xml2 berkdb innodb jpeg png pcre session unicode"
If you want to install also phpmyadmin, then you should also add pcre session unicode:
USE="apache2 mysql php pam ssl xml xml2 berkdb innodb jpeg png pcre session unicode"
I then changed the file /etc/init.d/apache2, in order to enable public_html folders for users (corresponding to the ~ directory), setting -D USERDIR:
APACHE2_OPTS="-D DEFAULT_VHOST -D PHP5 -D USERDIR
Before starting mysql, you must create (once and for all) the mysql main database, and this can be done simply by running:
/usr/bin/mysql_install_db