如果没有系统根密码设置，则无法更新mysql

Question

我正在尝试更新系统，但是mysql 5.7失败了。由于身份验证问题，它似乎无法连接。

以下是完整的控制台输出：

Reading package lists... Done
Building dependency tree
Reading state information... Done
mysql-server-5.7 is already the newest version (5.7.23-0ubuntu0.16.04.1).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
2 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
Setting up mysql-server-5.7 (5.7.23-0ubuntu0.16.04.1) ...
Renaming removed key_buffer and myisam-recover options (if present)
mysql_upgrade: Got error: 1045: Access denied for user 'root'@'localhost' (using password: NO) while connecting to the MySQL server
Upgrade process encountered error and will not continue.
mysql_upgrade failed with exit status 11
dpkg: error processing package mysql-server-5.7 (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mysql-server:
 mysql-server depends on mysql-server-5.7; however:
  Package mysql-server-5.7 is not configured yet.

dpkg: error processing package mysql-server (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 mysql-server-5.7
 mysql-server
E: Sub-process /usr/bin/dpkg returned an error code (1)

重要的bit：

 mysql_upgrade: Got error: 1045: Access denied for user 'root'@'localhost'

我可以使用"mysql -u root -p“命令登录。我不使用密码登录到服务器，因为我使用ssh键，如果这是重要的。

为什么现在会出现这个问题，如何解决这个问题呢？我也有很长一段时间没有更新系统了，但这是唯一有问题的包。

Answer 1

您可以尝试通过Unix启用mySQL的无密码登录，这通常是默认启用的，但可能已经更改了。

登录到mysql根shell并运行以下命令：

grant usage on *.* to 'root'@'localhost' identified via unix_socket;

如果这不起作用，请尝试添加一个包含内容的文件~/.my.cnf：

[client]
user=root
password=your_password

使其仅由所有者(和root用户)读取：

chmod 600 ~/.my.cnf

然后再试一次