https://dev.mysql.com/doc/refman/5.6/en/mysql-secure-installation.html
mysql_secure_installationは、perlで書かれたスクリプトで、MySQLのセキュリティを向上させることができる。
具体的には;
（MySQLの）rootのパスワード設定
localhost外からアクセス可能なrootアカウントの削除
anonymousユーザアカウントの削除
anonymousユーザ含め誰でもアクセス可能な「test」データベースの削除
test_から始まるデータベースへの接続権限の削除（デフォルトでは誰でもアクセスできる）
MySQLが動いている状態で、引数なしで実行すればよい。
sysrc mysql_enable=YES
mysql_enable: -> YES
service mysql-server start
Starting mysql.
立ち上げておいて。
mysql_secure_installationを引数なしで実行。
rootパスワード以外はリターンキー連打でよし。
# mysql_secure_installation
NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MySQL
SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY!
In order to log into MySQL to secure it, we'll need the current
password for the root user. If you've just installed MySQL, and
you haven't set the root password yet, the password will be blank,
so you should just press enter here.
Enter current password for root (enter for none):
OK, successfully used password, moving on...
Setting the root password ensures that nobody can log into the MySQL
root user without the proper authorisation.
Set root password? [Y/n] Y
New password:
Re-enter new password:
Password updated successfully!
Reloading privilege tables..
... Success!
By default, a MySQL installation has an anonymous user, allowing anyone
to log into MySQL without having to have a user account created for
them. This is intended only for testing, and to make the installation
go a bit smoother. You should remove them before moving into a
production environment.
Remove anonymous users? [Y/n] Y
... Success!
Normally, root should only be allowed to connect from 'localhost'. This
ensures that someone cannot guess at the root password from the network.
Disallow root login remotely? [Y/n] Y
... Success!
By default, MySQL comes with a database named 'test' that anyone can
access. This is also intended only for testing, and should be removed
before moving into a production environment.
Remove test database and access to it? [Y/n] Y
- Dropping test database...
... Success!
- Removing privileges on test database...
... Success!
Reloading the privilege tables will ensure that all changes made so far
will take effect immediately.
Reload privilege tables now? [Y/n] Y
... Success!
All done! If you've completed all of the above steps, your MySQL
installation should now be secure.
Thanks for using MySQL!
Cleaning up...```