5.7.10-fails to mount volume `/var/log/mysql`

[asmoker]

In oder to collect mysql error log and slow query log to logstash, I mount host volume /data/logs/mysql to the container /var/log/mysql:
My docker-compose.yml:

version: '2'
services:
mysql:
image: clkj.com/docker/mysql:5.7.10
container_name: mysql
restart: always
network_mode: "bridge"
privileged: true
environment:
- MYSQL_ROOT_PASSWORD=password
volumes:
- /data/mysql/var/lib/mysql:/var/lib/mysql
- ./conf:/etc/mysql/conf.d
- /data/logs/mysql:/var/log/mysql

and my conf/log.cnf:

[mysqld]
log-error = /var/log/mysql/error.log
slow_query_log = ON
slow_query_log_file = /var/log/mysql/slow.log
slow_launch_time = 2

but the container exited with code 0. The container runs up when I remove the - /data/logs/mysql:/var/log/mysql configuration;

OS: CentOS 7
MySQL: 5.7.10

[yosifkit]

Probably need to chown or chmod the /data/logs/mysql/ directory so that the mysql user from the container can write to it.

[asmoker]

@yosifkit Thanks for your reply.
I trid to chown and chmod the /data/logs/mysql/ directory, but that's no effect.
Beacause the dirctory was created by the mysql container, I think it has the permission to read and write the folder.

[ltangvald]

Anything from docker logs ?
Does it still happen if you disable slow_query_log (or just not map the config file)?
Could you try starting the container in interactive mode (-it and add a /bin/bash to the end of the run command) with the same mapping, then running myqld --initialize?

[asmoker]

@ltangvald
If I don't map the config file, the container can run up normally.
So, if I don't map the config file, the container runs up and mysqld also runs up, it can provide database service normally.
If I map the config file, the container won't run up and status is Restarting (1) 1 seconds ago, and I can't use the command docker exec --it mysql /bin/bash to access the container.
Maybe there is a problem with my config file?
😶

[ltangvald]

You can run
docker logs containerid
to see if anything was printed to stdout in the container before it shut down.
Can you try mapping up the config file, but removing the slow log options?
Might be an issue with the config file, but it's also possible there's a bug in the server that's being uncovered because of the uncommon way the docker script initializes the database.
Just to be sure, could you try the same setup but with a 5.7.11 image?

[yosifkit]

Still seems like a permission issue. I used your exact config and these are the steps I tried:

$ docker run -it --rm -v ~/dicker/tmp/my.cnf:/etc/mysql/conf.d/custom.cnf -v ~/dicker/tmp/mysql-logs/:/var/log/mysql/ --name mysql -e MYSQL_ROOT_PASSWORD=12345 mysql bash
root@1c384a908efa:/# /entrypoint.sh mysqld # try default command
Initializing database
root@1c384a908efa:/# mysqld --initialize # try to just init the database, no output :(
root@1c384a908efa:/# ls -al /var/lib/mysql/ # check contents of the directories
total 8
drwxr-xr-x  2 mysql mysql 4096 Mar 22 20:14 .
drwxr-xr-x 14 root  root  4096 Mar 17 22:24 ..
root@1c384a908efa:/# ls -al /var/log/mysql/
total 8
drwxr-sr-x 2 root 1000 4096 Mar 22 20:14 .
drwxr-xr-x 5 root root 4096 Mar 17 22:24 ..
root@1c384a908efa:/# exit
$ # ok, lets do a new container to be safe         
$ docker run -it --rm -v ~/dicker/tmp/my.cnf:/etc/mysql/conf.d/my.cnf -v ~/dicker/tmp/mysql-logs/:/var/log/mysql/ --name mysql -e MYSQL_ROOT_PASSWORD=12345 mysql bash
root@d27a8e03f5db:/# ls -al /var/log/mysql/ # still empty and owned by root and my group
total 8
drwxr-sr-x 2 root 1000 4096 Mar 22 19:52 .
drwxr-xr-x 5 root root 4096 Mar 17 22:24 ..
root@d27a8e03f5db:/# chown mysql:mysql /var/log/mysql/
root@d27a8e03f5db:/# /entrypoint.sh mysqld
Initializing database
Database initialized
MySQL init process in progress...
Warning: Unable to load '/usr/share/zoneinfo/Factory' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/iso3166.tab' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/leap-seconds.list' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/posix/Factory' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/right/Factory' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/zone.tab' as time zone. Skipping it.

/entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*


MySQL init process done. Ready for start up.

$ # looks like it is ready!
$ # from other terminal, let's test mysql client
$ docker exec -it mysql bash
root@d27a8e03f5db:/# mysql -p      
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.11-log MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

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

mysql> select 1;
+---+
| 1 |
+---+
| 1 |
+---+
1 row in set (0.00 sec)

mysql> 

The mount point will be owned by root or whoever created the folder on the host. You should be able to just do chown 999:999 /data/logs/mysql and it will work. If you need access by your host user, then it should work to put the group as your user's group like 1000 (and chmoding so that group has read access to everything).

[asmoker]

@yosifkit Thanks a lot.
That's really a permission issue. After I run chown 999:999 /data/logs/mysql, the container can run up and provide database service, and slow query log file was created in the dirctory /data/logs/mysql. Everything is OK.
What I confused before is that why the mysql container can't read and write the '/data/logs/mysql` even though the dirctory is created by the container.
However, Thanks a lot.
Please forgive my poor English.

[ltangvald]

The entrypoint script ensures the correct permission to datadir. Maybe we need to do something similar for logdir?

[yosifkit]

@ltangvald can we use the same --vebose --help to get any log directories that they have configured?

[ltangvald]

Yeah, I think we can do it in the same way, though I haven't tested it.

[luffyke]

@yosifkit hi, please help to fix this issue as there are many users meet it on SO. thanks a lot.

[kiwifly]

hi, I also meet this issue when I want persist /var/lib/mysql, and I fix this issue by using the following method~~

sudo docker volume create --name mysql_db
sudo docker run -d -v mysql_db:/var/lib/mysql <Container ID>
sudo docker volume inspect mysql_db

[mscislak]

Hi, I solved this issue by using the following command:

docker exec mysql chown mysql:root /var/log/mysql

[yu2003w]

By executing chown 999:999 solved the problem.