Configure AppArmor¶
Edit profile¶
Only edit /etc/apparmor.d/local/usr.sbin.mysql.
You should [switch the profile] to Complain mode before editing the file. Edit the file in any text editor. When finished, reload the profile and switch it to Enforce mode.
Configure data directory location¶
You can change the data directory to a non-default location, like /var/lib/mysqlcustom. You should enable audit mode to capture all actions and edit the profile to allow access to the custom location.
$ cat /etc/mysql/mysql.conf.d/mysqld.cnf
Expected output
The Percona Server 8.3 configuration file.
For explanations see
https://dev.mysql.com/doc/mysql/en/server-system-variables.html
[mysqld]
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
*datadir = /var/lib/mysqlcustom*
log-error = /var/log/mysql/error.log
Enable audit mode for mysqld. In this mode, the security policy is enforced and all access is logged.
$ aa-audit mysqld
Restart Percona Server for MySQL.
$ sudo systemctl mysql restart
The restart fails because AppArmor has blocked access to the custom data directory location. To diagnose the issue, check the logs for the following:
-
ALLOWED - A log event when the profile is in complain mode and the action violates a policy.
-
DENIED - A log event when the profile is in enforce mode and the action is blocked.
For example, the following log entries show DENIED:
Expected output
...
Dec 07 12:17:08 ubuntu-s-4vcpu-8gb-nyc1-01-aa-ps audit[16013]: AVC apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/var/lib/mysqlcustom/binlog.index" pid=16013 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=111 ouid=111
Dec 07 12:17:08 ubuntu-s-4vcpu-8gb-nyc1-01-aa-ps kernel: audit: type=1400 audit(1607343428.022:36): apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/var/lib/mysqlcustom/mysqld_tmp_file_case_insensitive_test.lower-test" pid=16013 comm="mysqld" requested_mask="c" denied_mask="c" fsuid=111 ouid=111
...
Open /etc/apparmor.d/local/usr.sbin.mysqld in a text editor and edit the following entries in the Allow data dir access section.
Allow data dir access
/var/lib/mysqlcustom/ r,
/var/lib/mysqlcustom/** rwk,
In etc/apparmor.d/local/usr.sbin.mysqld, comment out, using the # symbol, the current entries in the Allow data dir access section. This step is optional. If you skip this step, mysqld continues to access the default data directory location.
Note
Edit the local version of the file instead of the main profile. Separating the changes makes maintenance easier.
Reload the profile:
$ apparmor_parser -r -T /etc/apparmor.d/usr.sbin.mysqld
Restart mysql:
$ systemctl restart mysqld
Set up a custom log location¶
To move your logs to a custom location, you must edit the my.cnf configuration file and then edit the local profile to allow access:
cat /etc/mysql/mysql.conf.d/mysqld.cnf
Expected output
The Percona Server 8.3 configuration file.
For explanations see
https://dev.mysql.com/doc/mysql/en/server-system-variables.html
[mysqld]
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
datadir = /var/lib/mysql
log-error = /*custom-log-dir*/mysql/error.log
Verify the custom directory exists.
$ ls -la /custom-log-dir/
Expected output
total 12
drwxrwxrwx 3 root root 4096 Dec 7 13:09 .
drwxr-xr-x 24 root root 4096 Dec 7 13:07 ..
drwxrwxrwx 2 root root 4096 Dec 7 13:09 mysql
Restart Percona Server.
$ service mysql start
Expected output
Job for mysql.service failed because the control process exited with error code.
See "systemctl status mysql.service" and "journalctl -xe" for details.
$ journalctl -xe
Expected output
...
AVC apparmor="DENIED" operation="mknod" profile="/usr/sbin/mysqld" name="/custom-log-dir/mysql/error.log"
...
The access has been denied by AppArmor. Edit the local profile in the Allow log file access section to allow access to the custom log location.
$ cat /etc/apparmor.d/local/usr.sbin.mysqld
Expected output
Site-specific additions and overrides for usr.sbin.mysqld..
For more details, please see /etc/apparmor.d/local/README.
Allow log file access
/custom-log-dir/mysql/ r,
/custom-log-dir/mysql/** rw,
Reload the profile:
$ apparmor_parser -r -T /etc/apparmor.d/usr.sbin.mysqld
Restart Percona Server:
$ systemctl restart mysqld
Set secure_file_priv directory location¶
By default, secure_file_priv points to the following location:
mysql> mysqlshow variables like 'secure_file_priv';
Expected output
+------------------+-----------------------+
| Variable_name | Value |
+------------------+-----------------------+
| secure_file_priv | /var/lib/mysql-files/ |
+------------------+-----------------------+
To allow access to another location, in a text editor, open the local profile. Review the settings in the Allow data dir access section:
Allow data dir access
/var/lib/mysql/ r,
/var/lib/mysql/** rwk,
Edit the local profile in a text editor to allow access to the custom location.
$ cat /etc/apparmor.d/local/usr.sbin.mysqld
Expected output
Site-specific additions and overrides for usr.sbin.mysqld..
For more details, please see /etc/apparmor.d/local/README.
Allow data dir access
/var/lib/mysqlcustom/ r,
/var/lib/mysqlcustom/** rwk,
Reload the profile:
$ apparmor_parser -r -T /etc/apparmor.d/usr.sbin.mysqld
Restart Percona Server for MySQL:
$ systemctl restart mysqld
AppArmor links:¶
AppArmor
AppArmor Profiles
Manage AppArmor Profiles
Disable AppArmor
Troubleshoot AppArmor
Get expert help¶
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