How to add a CD-ROM device to a profile?

Incus
1

I’m trying to get Automatic Ripping Machine in its docker form to work in a container via a profile and container instance created with that profile.

I cannot solve is how to add the CD-ROM device to the profile.

I have tried acting like it is a disk, to no avail:
sudo incus profile device add Ripz cdrom disk source=/dev/sr0 path=/dev/sr0

This fails with Failed to start device "cdrom": Failed detecting source path "/dev/sr0" block device filesystem: Failed to run: blkid -s TYPE -o value /dev/sr0: exit status 2

Based on these old links reddit post and blog post, I cooked up these calls after finding how to call lxc calls directly (theoretically):

sudo incus profile set Ripz raw.lxc.cgroup.devices.allow='b 11:0 rwm'
sudo incus profile set Ripz raw.lxc.autodev=1
sudo incus profile set Ripz raw.lxc.hook.autodev='sh -c "mknod -m 666 /dev/sr0 b 11 0; ln -s /dev/sr0 /dev/cdrom"'

These fail with Error: Unknown configuration key: and the key following, indicating that this is not the way to set lxc settings - yet the description sounds like it should be. I could also be lost in time such that these are no longer relevant lxc settings, since the links are between 6 and 9 years old. It’s not clear to me how to find relevant ones, if the names changed.

I also have attached to the profile

sudo incus profile set Ripz security.nesting=true
sudo incus profile set Ripz security.syscalls.intercept.mknod=true
sudo incus profile set Ripz security.syscalls.intercept.setxattr=true

The first lets docker work, the second would let a mknod command work I assume, and the third honestly idk I found it with an add-a-GPU guide and seemed like an idea here.

The autoripper docker will call udevadm info --query=env /dev/sr0 to check /dev/sr0 on startup, so that call in the Ripz instance is my baseline to see if the cdrom access works. Some relevant output is here just in case it’s needed:

❯ udevadm info --query=env /dev/sr0
DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/ata6/host5/target5:0:0/5:0:0:0/block/sr0
DEVNAME=/dev/sr0
DEVTYPE=disk
DISKSEQ=9
MAJOR=11
MINOR=0
SUBSYSTEM=block
USEC_INITIALIZED=3515651
ID_CDROM=1

Love using Incus btw, thanks for forkin and keeping it truckin!

Edit: full command in case someone finds this is

sudo incus profile device add Ripz cdrom unix-block source=/dev/sr0
2

Try unix-block source=/dev/sr0

1 Like
3

Sadly it looks like eject does not work, nor any disc detection. Next benchmark is for eject to work in the container, I guess!

This snippet of errors comes from the docker itself:

eject: tried to use `/dev/mapper/shotbox--vg-root' as device name but it is no block device
eject: tried to use `/mnt//dev/sr0' as device name but it is no block device
eject: device name is `/dev/sr0'
eject: expanded name is `/dev/sr0'
eject: `/dev/mapper/shotbox--vg-root' is mounted at `/dev/sr0'
eject: expanded name is `/mnt//dev/sr0'
eject: `/mnt//dev/sr0' is not mounted
eject: `/mnt//dev/sr0' is not a mount point
eject: unable to find or open device for: `/dev/sr0'

Calling eject in the container yields a similar error:

root@autoripper:~# eject /dev/sr0
eject: /dev/mapper/shotbox--vg-root: not found mountpoint or device with the given name

As far as I can tell, shotbox--vg-root is the main drive of my computer. I’m not sure why that’s getting linked to /dev/sr0 instead of the actual /dev/sr0.

I added /dev/sr0 with sudo incus profile device add Ripz cdrom unix-block source=/dev/sr0

udevadm info --query=env /dev/sr0 also gives only 6 lines in the container instead of the many, many lines in the main OS. They’re the same 6 lines as the main OS, though. Was hoping that was good enough - mayhaps not.

Any ideas why /dev/sr0 is getting lost?

4

What does eject -F -m -r -v /dev/sr0 get you?

5

Thanks for the quick reply!

The response calling that in the container is:

root@autoripper:~# eject -F -m -r -v /dev/sr0
eject: device name is `/dev/sr0'
eject: /dev/mapper/shotbox--vg-root: mounted on /dev/sr0
eject: /dev/mapper/shotbox--vg-root: not found mountpoint or device with the given name
6

I tried adding the CD-ROM drive as a PCI device (...pci address=/devices/pci... from the udevadm info above), but that didn’t work. That was a small hope since the PCI device is the SATA controller not the drive itself.

I haven’t been able to finagle any other solution.

The aforementioned blog post did get it working a long long while ago, so LXC can do it. I wasn’t able to get the direct-to-LXC calls working that mimic what said blog post shows:

sudo incus profile set Ripz raw.lxc.cgroup.devices.allow='b 11:0 rwm'
sudo incus profile set Ripz raw.lxc.autodev=1
sudo incus profile set Ripz raw.lxc.hook.autodev='sh -c "mknod -m 666 /dev/sr0 b 11 0; ln -s /dev/sr0 /dev/cdrom"

Do you have experience with .lxc.calls via Incus to set LXC settings directly? That might be what is needed to get this working