Cannot make SCHROOT work for me

[mabra]

I try to use a chroot with schroot on debian bullseye. I setup a chroot fpr 'nomacs', an application,
I need the whole day, but is not in bullseye. I created a chroot for it, just to protect my host from garbage in its filesystem (the installation itself) -- strictly spoken, I do not need the protection of the host filesystem from the chroot, I want to access nearly all (homedir/net mounts - came not that far).

I tried to follow the instructions I found for schroot, but it does not work for me - instructions in the internet describe different settings, like own subdir for each chroot, with its own 'fstab', for example.
My example/setup changed nothing else (so "default" fstab from schroot subdirs should apply).

In the existing 'schroot.conf', everything is a comment and I added:

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[buster-test]
description=Run nomacs from buster
type=directory
directory=/opt/apps/deb10-apps
users=mbu
root-groups=root
profile=desktop
personality=linux
preserve-environment=true

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$ schroot -l
chroot:buster-test

My '/opt/apps/deb10-apps' is mounted with dev,exec,suid, it is a zfs filesystem,
mounted at: '/opt/apps/deb10-apps/'

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ls /opt/apps/
drwxrwxrwx 18 root root 24 2023-06-08 17:51:01 deb10-apps/

My user has bash as its shell.

Using chroot as root:
'chroot /opt/apps/deb10-apps/ bash'
I can see:

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(buster-test)root@mtx:/# cat /etc/issue
Debian GNU/Linux 10 \n \l

There wre no issues setting the chroot up.

From my user, I started:

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schroot -c buster-test
and this raises errors:
>W: Failed to change to directory ‘/home/mbu/work’: No such file or directory
I: The directory does not exist inside the chroot.  Use the --directory option to run the command in a different directory.
W: Falling back to directory ‘/home/mbu’

BTW, the message: "‘/home/mbu/work’: No such file or directory" may result from a chdir in my users .bashrc, but it appears even, when the chdir is set to be a comment. The same BAD appears, if I use schroot for the root-user - its home directory is empty.

issuing 'pwd' says: '/home/mbu', but 'ls -al' shows nothing, ls ..

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(buster-test)mbu@mtx:~$ ls -al
total 10
drwxr-xr-x  2 root root  2 Jul 21 09:28 .
drwxr-xr-x 11 root root 12 Jul 25 13:20 ..
(buster-test)mbu@mtx:~$ ls -al ..
total 52
drwxr-xr-x 11 root    root    12 Jul 25 13:20 .
drwxrwxrwx 18 root    root    24 Jun  8 17:51 ..
drwxr-xr-x  2 root    root     2 Jan  2  2023 mbt
drwxr-xr-x  2 root    root     2 Jul 21 09:28 mbu
lrwxrwxrwx  1 root    mbg-adm  6 Sep 28  2022 root -> /root/
drwxr-xr-x  2 root    root     2 Oct 10  2022 shared

mount:

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(buster-test)mbu@mtx:~$ mount
combopool/apps/deb10-apps on / type zfs (rw,xattr,posixacl)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=32842992k,nr_inodes=8210748,mode=755,inode64)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
syspool/home on /home type zfs (rw,xattr,posixacl)
syspool/tmp on /tmp type zfs (rw,xattr,posixacl)
syspool/ROOT/debian on /var/lib/dbus type zfs (rw,xattr,posixacl)

Some help would be great!
I would not know a way to start the app (with its necesary environment)
from the chroot or even a container (container as VM is easy).

Regards,
Manfred

[lindi]

I used to use something like https://lindi.iki.fi/lindi/schroot.txt when I needed to run software from debian unstable regularly. I haven't checked these instructions recently but maybe they can help you?

[mabra]

Tjanks for your reply.
But uups, this - to my understanding fo schroot - should be done by schroot itself.
This looks like some workaround? But I am unable to understand and this looks
like hand-woven chroot? The mentioned fstab, which one would this be?
There is already one in the tree of /etc/schroot - but what is in there, is NOT mounted.
What I found out later, there is also a systemd-unit - no documentation to find ....
Thanks anyway!
Regards,
Manfred

[lindi]

Yes you are right, I wanted to have the filesystems always mounted probably to speed up schroot and make it more naturla to have long-running daemons there.

[lindi]

So eassentially I am using schroot only to allow regular users to chroot, I wasn't using any other features.