[MDEV-32166] mysql_install_db creates mysql_upgrade_info file with different owner Created: 2023-09-14  Updated: 2024-01-08  Resolved: 2024-01-08

Status: Closed
Project: MariaDB Server
Component/s: None
Affects Version/s: 10.4, 10.8.8, 10.7, 10.5.22, 10.6.14, 10.6.15, 10.9.8, 10.10.6, 10.11.5, 11.0.3, 11.1.2
Fix Version/s: N/A

Type: Bug Priority: Major
Reporter: Hartmut Holzgraefe Assignee: Unassigned
Resolution: Incomplete Votes: 0
Labels: None

Issue Links:
Problem/Incident
is caused by MDEV-27607 mysql_install_db to install mysql_upg... Closed
Relates
relates to MDEV-15207 mysql_upgrade cannot create file mysq... Closed
relates to MDEV-23008 store mysql_upgrade version info in s... Open

 Description   

When running mysql_install_db with --user=... option all files in the created datadir will be owned by the given user, with the exception of mysql_upgrade_info which is owned by the user that executed the script, e.g.:

# mysql_install_db --user=mysql
 
[...]
 
# ls -l /var/lib/mysql
 
total 111040
 
-rw-rw---- 1 mysql mysql    417792 Sep 14 06:56 aria_log.00000001
 
-rw-rw---- 1 mysql mysql        52 Sep 14 06:56 aria_log_control
 
-rw-rw---- 1 mysql mysql       942 Sep 14 06:56 ib_buffer_pool
 
-rw-rw---- 1 mysql mysql  12582912 Sep 14 06:56 ibdata1
 
-rw-rw---- 1 mysql mysql 100663296 Sep 14 06:56 ib_logfile0
 
drwx------ 2 mysql mysql      4096 Sep 14 06:56 mysql
 
-rw-r--r-- 1 root  root         15 Sep 14 06:56 mysql_upgrade_info
 
drwx------ 2 mysql mysql      4096 Sep 14 06:56 performance_schema
 
drwx------ 2 mysql mysql     12288 Sep 14 06:56 sys
 
drwx------ 2 mysql mysql      4096 Sep 14 06:56 test



 Comments   
Comment by Hartmut Holzgraefe [ 2023-09-14 ]

Only tested on latest 10.11 so far, but probably effects all versions after MDEV-27607 "fixed in"

Comment by Hartmut Holzgraefe [ 2023-09-14 ]

Another reason for not having this info in a file, but in the database itself ...

Comment by Sergei Golubchik [ 2023-09-14 ]

why is it a bug?

Comment by Hartmut Holzgraefe [ 2023-10-16 ]

From KB on the "--user" option:

"The login user name to use for running mysqld. Files and directories created by mysqld will be owned by this user."

I know that this specific file is not created by mysqld/mariadbd, but the average user wouldn't necessarily know, and may get confused by ownership of this one specific file in the datadir not being affected.

Also this breaks things if a user lager chooses to run mysql_upgrade as the regular database system user ("mysql") instead of as ("root"), even though mysql_upgrade should not require root privileges otherwise

Comment by Sergei Golubchik [ 2023-10-16 ]

mysql_upgrade_info is owned by the user that mariadb-upgrade was run under. It's not really specific to mariadb-install-db, one can run mariadb-upgrade after installation as root and then as some other user, and get exactly the same issue.

So, basically, you're saying that mariadb-upgrade should chown the file it creates in the datadir to be owned by the owner of the datadir. Is that the desirable behavior?

Comment by Daniel Black [ 2023-10-17 ]

When the file exists, mariadb-upgrade rewrites the file contents, so fixing mariadb-install-db is desirable to get the base file right. When the file doesn't exist, yes changing the ownership to the datadir owner sound like a good addition too.

Comment by Sergei Golubchik [ 2023-11-20 ]

why is it a good addition? what is the goal, to allow someone to run mariadb-upgrade alternately as root and as mysql user? Like on even weeks as root and on odd weeks as mysql? Is this what you're trying to get working?

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