CentOS7-Mysql5.7配置（四）

2.10.4 Securing the Initial MySQL Account

The MySQL installation process involves initializing the data directory, including the grant tables in the mysqlsystem database that define MySQL accounts. For details, see Section 2.10.1, “Initializing the Data Directory”.

This section describes how to assign a password to the initial root account created during the MySQL installation procedure, if you have not already done so.

Note

Alternative means for performing the process described in this section:

• On Windows, you can perform the process during installation with MySQL Installer (see Section 2.3.3, “MySQL Installer for Windows”).

• On all platforms, the MySQL distribution includes mysql_secure_installation, a command-line utility that automates much of the process of securing a MySQL installation.

• On all platforms, MySQL Workbench is available and offers the ability to manage user accounts (see Chapter 30, MySQL Workbench ).

A password may already be assigned to the initial account under these circumstances:

• On Windows, installations performed using MySQL Installer give you the option of assigning a password.

• Installation using the macOS installer generates an initial random password, which the installer displays to the user in a dialog box.

• Installation using RPM packages generates an initial random password, which is written to the server error log.

• Installations using Debian packages give you the option of assigning a password.

• For data directory initialization performed manually using mysqld --initialize, mysqld generates an initial random password, marks it expired, and writes it to the server error log. See Section 2.10.1, “Initializing the Data Directory”.

The mysql.user grant table defines the initial MySQL user account and its access privileges. Installation of MySQL creates only a 'root'@'localhost' superuser account that has all privileges and can do anything. If the root account has an empty password, your MySQL installation is unprotected: Anyone can connect to the MySQL server as root without a password and be granted all privileges.

The 'root'@'localhost' account also has a row in the mysql.proxies_priv table that enables granting the PROXY privilege for ''@'', that is, for all users and all hosts. This enables root to set up proxy users, as well as to delegate to other accounts the authority to set up proxy users. See Section 6.2.14, “Proxy Users”.

To assign a password for the initial MySQL root account, use the following procedure. Replace root-password in the examples with the password that you want to use.

Start the server if it is not running. For instructions, see Section 2.10.2, “Starting the Server”.

The initial root account may or may not have a password. Choose whichever of the following procedures applies:

• If the root account exists with an initial random password that has been expired, connect to the server as root using that password, then choose a new password. This is the case if the data directory was initialized using mysqld --initialize, either manually or using an installer that does not give you the option of specifying a password during the install operation. Because the password exists, you must use it to connect to the server. But because the password is expired, you cannot use the account for any purpose other than to choose a new password, until you do choose one.

  1. If you do not know the initial random password, look in the server error log.

  2. Connect to the server as root using the password:

     shell> mysql -u root -p
     Enter password: (enter the random root password here)
     

  3. Choose a new password to replace the random password:

     mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'root-password';
     

• If the root account exists but has no password, connect to the server as root using no password, then assign a password. This is the case if you initialized the data directory using mysqld --initialize-insecure.

  1. Connect to the server as root using no password:

     shell> mysql -u root --skip-password
     

  2. Assign a password:

     mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'root-password';
     

After assigning the root account a password, you must supply that password whenever you connect to the server using the account. For example, to connect to the server using the mysql client, use this command:

shell> mysql -u root -p
Enter password: (enter root password here)

To shut down the server with mysqladmin, use this command:

shell> mysqladmin -u root -p shutdown
Enter password: (enter root password here)

Note

For additional information about setting passwords, see Section 6.2.10, “Assigning Account Passwords”. If you forget your root password after setting it, see Section B.4.3.2, “How to Reset the Root Password”.

To set up additional accounts, see Section 6.2.7, “Adding Accounts, Assigning Privileges, and Dropping Accounts”.

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User Comments

User comments in this section are, as the name implies, provided by MySQL users. The MySQL documentation team is not responsible for, nor do they endorse, any of the information provided here.

Posted by n/a n/a on August 23, 2017

For MySQL 5.7.16 on Ubuntu 16.04, the default authentication plugin for user 'root' (empty host) is 'auth_socket'. This basically means you cannot set a password for that user, and root is always allowed to log in if it uses the socket (i.e. 'localhost' as the host to connect to). This should be reasonable secure since only root can access that socket and if your root account is compromised, you're already dead in the water. If you want to set a password for the root account anyway, you can change the plugin to 'mysql_native_password':

update user set plugin='mysql_native_password' where user='root' and host='localhost';

and then change the root password.