Memo: MariaDBのインストール/初期設定


# はじめに
MariaDBのインストールから初期設定をする機会があったのでメモしておく。

# 環境情報

- OS: CentOS7.1

# 手順
## Install

以下のコマンドでインストール出来る。

```
$ sudo yum install -y mariadb mariadb-devel mariadb-server 
```

## 設定ファイル作成
以下のコマンドで最小構成のサーバー設定ファイルをコピーする。

```
$ cp -p /usr/share/mysql/my-small.cnf /etc/my.cnf.d/server.cnf
```

デフォルトのままでも動作するが、以下の行を追加することで日本語設定とdataディレクトリを変更出来る。

```
[client]
default-character-set = utf8

[mysqld]
datadir = /datas
character-set-server = utf8
```

## 初期設定

以下で初期設定を行う。
初期rootパスワードは入力無しでEnterを押せば次に処理が進む。

```
$ sudo systemctl start mariadb.service
$ sudo /usr/bin/mysql_secure_installation
/usr/bin/mysql_secure_installation: 行 379: find_mysql_client: コマンドが見つかりません

NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB
      SERVERS IN PRODUCTION USE!  PLEASE READ EACH STEP CAREFULLY!

In order to log into MariaDB to secure it, we'll need the current
password for the root user.  If you've just installed MariaDB, 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 MariaDB
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 MariaDB installation has an anonymous user, allowing anyone
to log into MariaDB 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, MariaDB 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!

Cleaning up...

All done!  If you've completed all of the above steps, your MariaDB
installation should now be secure.

Thanks for using MariaDB!
$
```

## DB作成
まずはrootユーザーでログインする。

```
$ mysql -uroot -p
Enter password: 
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 4300
Server version: 5.5.41-MariaDB MariaDB Server

Copyright (c) 2000, 2014, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> CREATE DATABASE ${db_name} DEFAULT CHARACTER SET utf8;
```

## 権限設定
以下のコマンドで作成したDBに対して特定のユーザーのアクセス権限を設定する。
`${user}@'%'`を指定することで全てのIPからのアクセスを許可している。

```
MariaDB [(none)]> GRANT ALL PRIVILEGES ON ${db_name}.* TO ${user}@'%' IDENTIFIED BY '${password}';
```

## テーブル作成
作成したユーザーでログインして、Tableを作成する。
以下簡単なテーブル、idとnameカラムを持つテーブルを作成している。

```
MariaDB [(none)]> exit
$ mysql -u${user} -D${db_name} -p
Enter password: 
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 13
Server version: 5.5.41-MariaDB MariaDB Server

Copyright (c) 2000, 2014, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [${db_name}]> CREATE TABLE ${table_name} ( ¥
	id INT AUTO_INCREMENT PRIMARY KEY,¥
	name VARCHAR(100)¥
	);
Query OK, 0 rows affected (0.01 sec)

MariaDB [${db_name}]> DESC ${table_name}; 
+-------+--------------+------+-----+---------+----------------+
| Field | Type         | Null | Key | Default | Extra          |
+-------+--------------+------+-----+---------+----------------+
| id    | int(11)      | NO   | PRI | NULL    | auto_increment |
| name  | varchar(100) | YES  |     | NULL    |                |
+-------+--------------+------+-----+---------+----------------+
2 rows in set (0.01 sec)

MariaDB [${db_name}]> 
```

おしまい。