Ideas on how to make the OMV in LXC work with ZFS bind mounts

[shalak]

The solution mention in discussions/175 suggests adding a new block device, so it's detected by OMV itself - no bind mounts.

The other solution to make OMV be able to create Shared Folders, would be to use the sharerootfs plugin - however, this plugin depends on fstab entries. Unfortunately, in the LXC it's empty:

root@omv-testing:~# cat /etc/fstab
# UNCONFIGURED FSTAB FOR BASE SYSTEM

If we could only somehow make it that the LXC container add a the / entry there, maybe the whole thing would work with bind mounts.

Anybody got idea how to make this work?

[shalak]

I tried manually adding dummy entry to /etc/fstab:

/dev/root / ext4 defaults 0 1

And then I executed salt-call --local --retcode-passthrough --no-color --out=json mount.fstab, it showed it:

{
    "local": {
        "/": {
            "device": "/dev/root",
            "fstype": "ext4",
            "opts": [
                "defaults"
            ],
            "dump": "0",
            "pass": "1"
        }
    }
}

However, installation of the sharerootfs plugin fails:

[ERROR   ] An un-handled exception was caught by Salt's global exception handler:
DeviceNotFoundByFileError: [Errno 2] No such file or directory: 'fast/subvol-104-disk-0'
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/pyudev/device/_device.py", line 221, in from_device_file
    device_type = get_device_type(filename)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/pyudev/_util.py", line 122, in get_device_type
    mode = os.stat(filename).st_mode
           ^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: 'fast/subvol-104-disk-0'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/salt-call", line 33, in <module>
    sys.exit(load_entry_point('salt==3007.0', 'console_scripts', 'salt-call')())
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/scripts.py", line 444, in salt_call
    client.run()
  File "/usr/lib/python3/dist-packages/salt/cli/call.py", line 50, in run
    caller.run()
  File "/usr/lib/python3/dist-packages/salt/cli/caller.py", line 95, in run
    ret = self.call()
          ^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/cli/caller.py", line 202, in call
    ret["return"] = self.minion.executors[fname](
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 149, in __call__
    return self.loader.run(run_func, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 1234, in run
    return self._last_context.run(self._run_as, _func_or_method, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 1249, in _run_as
    return _func_or_method(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/executors/direct_call.py", line 10, in execute
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 149, in __call__
    return self.loader.run(run_func, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 1234, in run
    return self._last_context.run(self._run_as, _func_or_method, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 1249, in _run_as
    return _func_or_method(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/var/cache/salt/minion/extmods/modules/omv_utils.py", line 242, in get_root_filesystem
    return fs.predictable_device_file
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/openmediavault/fs/__init__.py", line 193, in predictable_device_file
    if self.has_device_file_by_uuid():
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/openmediavault/device/block.py", line 171, in has_device_file_by_uuid
    return is_device_file_by_uuid(self.device_file_by_uuid)
                                  ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/openmediavault/device/block.py", line 186, in device_file_by_uuid
    for device_link in self.device_links:
                       ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/openmediavault/device/block.py", line 89, in device_links
    device = pyudev.Devices.from_device_file(context, self.device_file)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/pyudev/device/_device.py", line 224, in from_device_file
    raise DeviceNotFoundByFileError(err)
pyudev._errors.DeviceNotFoundByFileError: [Errno 2] No such file or directory: 'fast/subvol-104-disk-0'
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/pyudev/device/_device.py", line 221, in from_device_file
    device_type = get_device_type(filename)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/pyudev/_util.py", line 122, in get_device_type
    mode = os.stat(filename).st_mode
           ^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: 'fast/subvol-104-disk-0'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/salt-call", line 33, in <module>
    sys.exit(load_entry_point('salt==3007.0', 'console_scripts', 'salt-call')())
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/scripts.py", line 444, in salt_call
    client.run()
  File "/usr/lib/python3/dist-packages/salt/cli/call.py", line 50, in run
    caller.run()
  File "/usr/lib/python3/dist-packages/salt/cli/caller.py", line 95, in run
    ret = self.call()
          ^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/cli/caller.py", line 202, in call
    ret["return"] = self.minion.executors[fname](
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 149, in __call__
    return self.loader.run(run_func, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 1234, in run
    return self._last_context.run(self._run_as, _func_or_method, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 1249, in _run_as
    return _func_or_method(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/executors/direct_call.py", line 10, in execute
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 149, in __call__
    return self.loader.run(run_func, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 1234, in run
    return self._last_context.run(self._run_as, _func_or_method, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/salt/loader/lazy.py", line 1249, in _run_as
    return _func_or_method(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/var/cache/salt/minion/extmods/modules/omv_utils.py", line 242, in get_root_filesystem
    return fs.predictable_device_file
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/openmediavault/fs/__init__.py", line 193, in predictable_device_file
    if self.has_device_file_by_uuid():
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/openmediavault/device/block.py", line 171, in has_device_file_by_uuid
    return is_device_file_by_uuid(self.device_file_by_uuid)
                                  ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/openmediavault/device/block.py", line 186, in device_file_by_uuid
    for device_link in self.device_links:
                       ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/openmediavault/device/block.py", line 89, in device_links
    device = pyudev.Devices.from_device_file(context, self.device_file)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/pyudev/device/_device.py", line 224, in from_device_file
    raise DeviceNotFoundByFileError(err)
pyudev._errors.DeviceNotFoundByFileError: [Errno 2] No such file or directory: 'fast/subvol-104-disk-0'
Updating configuration ...

END OF LINE

The fast/subvol-104-disk-0 is of course, the bind mount on the fast ZFS zpool.