lxc Container (Proxmox) Nextcloud problem - lxc

Question

I created a lxc Container with Proxmox using
https://www.turnkeylinux.org/download?file=turnkey-nextcloud-17.1-bullseye-amd64.iso
i have mount a harddisk to the proxmox main system with
root#pve:/mnt/nas/data# pct set 101 -mp0 /mnt/nas ,mp=/mnt/nextcloud
but i have the problem , the folder permissions are nobody:nogroup and i cant change it as root user inside the lxc container.
And the www-data user/group are exist in the lxc Container,but not shown as about the commands.
that is from the Proxmox System
root#pve:/mnt/nas# ls -la
total 29
drwxr-xr-x 5 root root 4096 Jan 9 13:53 .
drwxr-xr-x 3 root root 3 Jan 14 12:10 ..
drwxr-xr-x 2 root root 4096 Jan 3 08:01 code
drwxr-x--- 10 www-data www-data 4096 Jan 9 23:05 data
drwx------ 2 root root 16384 Nov 24 10:39 lost+found
root#pve:/mnt/nas# cat /etc/fstab
# \<file system\> \<mount point\> \<type\> \<options\> \<dump\> \<pass\>
proc /proc proc defaults 0 0
UUID=7a2cccf9-745c-462a-acf8-80bca216da85 /mnt/nas ext4 defaults 0 1
root#pve:/mnt/nas#
from the lxc Container is this :
root#Nextcloud /mnt# ls
nextcloud
root#Nextcloud /mnt# ls -la
total 13
drwxr-xr-x 3 root root 3 Jan 14 11:14 .
drwxr-xr-x 17 root root 23 Jan 14 11:09 ..
drwxr-xr-x 5 nobody nogroup 4096 Jan 9 12:53 nextcloud
root#Nextcloud /mnt# chown -R www-data:www-data /mnt/nextcloud/data/
chown: cannot read directory '/mnt/nextcloud/data/': Permission denied
root#Nextcloud /mnt# chown -R root:root /mnt/nextcloud/data/
chown: cannot read directory '/mnt/nextcloud/data/': Permission denied
root#Nextcloud /mnt# groups
root
root#Nextcloud /mnt# addgroup www-data
addgroup: The group \`www-data' already exists.
root#Nextcloud /mnt#
how i can solved that problem?
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Answer 1

LXC uses linux namespaces to separate user IDs from the host. By default the UID 0 (root) inside the container is seen as UID 100000 by the Proxmox host. That's why the directory you're bind-mounting, which is owned by www-data (UID 33) from the host perspective is nobody:nogroup inside the container.
There are a couple ways to deal with this, but my preferred method, if you can get away with it, is to change the owner of the directory from the host to the desired UID + 100000. So in this case, do chown -R 100033:100033 /mnt/nas and that should give you the desired permissions in the container.
If it's important to keep the permissions as they are from the host perspective, try using an ID map (there's a good description in the Proxmox wiki: https://pve.proxmox.com/wiki/Unprivileged_LXC_containers; and also a website to help calculate the proper UID numbers: https://proxmox-idmap-helper.nieradko.com/)

Answer 2

root#Nextcloud ~# cd /mnt
root#Nextcloud /mnt# ls
nextcloud
root#Nextcloud /mnt# cd nextcloud/
root#Nextcloud /mnt/nextcloud# ls
code data lost+found
root#Nextcloud /mnt/nextcloud# cd data/
root#Nextcloud .../nextcloud/data# ls
Biene appdata_oczb14gwpmn2 flow.log nextcloud.log.1
Meltymon audit.log flow.log.1 owncloud.db
__groupfolders biene index.html updater-oczb14gwpmn2
appdata_ochaal06qhnm files_external nextcloud.log updater.log
root#Nextcloud .../nextcloud/data# cd ..
root#Nextcloud /mnt/nextcloud# ls -la
total 29
drwxr-xr-x 5 www-data www-data 4096 Jan 9 12:53 .
drwxr-xr-x 3 root root 3 Jan 14 11:14 ..
drwxr-xr-x 2 www-data www-data 4096 Jan 3 07:01 code
drwxr-x--- 10 www-data www-data 4096 Jan 9 22:05 data
drwx------ 2 www-data www-data 16384 Nov 24 09:39 lost+found
root#Nextcloud /mnt/nextcloud#
Nice it Works!
i must be install sudo for reinitialize the Database and Folders
sudo -u www-data php occ files:scan --all
sudo -u www-data php occ db:add-missing-indices
And give the occ file the x permissions
chown +x /var/www/nextcloud/occ
Thank you so much,ive searched the hole day for a solution with Google but dont find anything like that.