docker and SMB shares
reddit / selfhosted

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steve_docker · 2023-10-14 12:08

Hi, I am trying to run a docker-compose file (seafile if that makes
any difference). This works fine if dockerroot and all of the data
volumes are located on the local filesystem. (Which is an Ubuntu
proxmox VM)

However I am running into problems when trying to move the data volume
and/or dockerroot to an SMB mounted from another machine. (In case it
makes any difference they are both ubuntu VM's running under proxmox
on a 192.168.x.x.).

I \*believe\* I have the correct permissions on the SMB share, local
mount point and on the VM running docker. Also when I run "docker-
compose up" I do see docker successfully writing files to the SMB
share. There are no errors shown in /var/log/samba on the server.

The SMB share is mounted on the docker host with an /etc/fstab as
below:

[//192.168.1.163/proxshare](//192.168.1.163/proxshare) /mnt/sambashare
cifs
username=auser,password=,uid=1000,rw,file\_mode=0777,dir\_mode=0777 0
0

The user 'auser' and root can read and write to the SMB share via
normal commands like touch etc.

​

Permissions for the directory on the samba server are:

drwxr-xr-x 13 auser auser  4096 Oct 14 12:29 sambashare

​

Permissions for the mount point on the remote VM running docker are:

drwxrwxrwx 2 auser root 0 Oct 14 11:29 sambashare

​

So I'm at a loss as to why this doesn't work. In case it helps its the
mariadb docker container that seems to be having problems when being
run with docker volume being set to be the smb share.

​

I'm wondering:

1) Should this work and should docker/the OS see /mnt/sambashare as
pretty much just a local directory?

2) Do I need to give the \`docker\` user special permissions to this
share?

​

​

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thekrautboy · 2023-10-14 12:16

* Why SMB between two Linux machines? Use NFS and save yourself a
headache. Use SMB only when its required because Windows is involved.

> Should this work and should docker/the OS see /mnt/sambashare as
pretty much just a local directory?

With the way you set it up, yes. Docker isnt even aware its a SMB
share, it only uses that directory you tell it to. So the problem
cannot be Docker here, atleast not directly.

Most likely you have a permissions issue between the user that is
running inside the container, the Docker host and the SMB host.

> Do I need to give the `docker` user special permissions to this
share?

Thats your hint.

Alternatively you could use SMB (or better NFS) directly as Docker
volumes, Docker has builtin volume drivers for that, this would allow
you to skip the mounting on the Docker host and possibly make
permissions easier to handle.

https://docs.docker.com/storage/volumes/#use-a-volume-driver

Also, /r/Docker exists but my guess this is more fitting for
/r/LinuxQuestions and /r/Linux4Noobs

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[deleted] · 2023-10-14 12:22

[removed]

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[deleted] · 2023-10-14 12:57

[removed]