[lxc-users] How to provide device access to lxc unprivileged containers ?

[Yasoda Padala]

Hi Andrey,
Thank you for your response.
As you suggested, for block devices I can mount the device into container
FS and can perform read/write on it.
But I have the requirement to make char devices also (eg. HID card reader/
barcode reader) accessible to unprivileged containers.
Added the following entries in container config file
1. lxc.cgroup.devices.allow = c 180:* rw
lxc.mount.entry = /dev/usb/ dev/usb/ none bind,create=dir 0 0
2. Changed device owner to 100000
3. changed device permission to 777.on the host
when I run lsusb (usb utility) inside the container, it is not enumerating
the devices attached to the system. My knowledge on working with devices
and lxc containers is very limited. I am new to linux and containerized
apps development and still learning. If I am missing anything, please help.
Thanks in advance,
Yasoda
On Tue, Sep 11, 2018 at 5:30 PM <

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1. How to provide device access to lxc unprivileged containers ?
(Yasoda Padala)
2. Re: How to provide device access to lxc unprivileged
containers ? (Andrey Repin)
---------- Forwarded message ----------
Date: Tue, 11 Sep 2018 14:15:32 +0530
Subject: [lxc-users] How to provide device access to lxc unprivileged
containers ?
Hi All,
I have a usb attached to my ubuntu machine (16.04) and trying to access
that device from unprivileged lxc container.
By access I mean, enumerate and do I/O on that device.
I have written a small program using libusb library and using that libusb
executable to enumerate,read/write usb device from container
Please find attached lxc config file and libusb executable.
I have found plenty of examples in various forums but nothing worked for
me.
1. Added below entries in lxc config file
lxc.cgroup.devices.allow = b 8:* rwm
lxc.mount.entry = /dev/bus/usb/001/ dev/bus/usb/001/ none bind,create=dir
0 0
lxc.mount.entry = /dev/sdc
/home/oxpd/.local/share/lxc/Test/rootfs/dev/sdc none bind,create=file 0 0
lxc.mount.entry = /dev/sdc1
/home/oxpd/.local/share/lxc/Test/rootfs/dev/sdc1 none bind,create=file 0 0
2. Changed device owner to 100000
3. changed device permission to 777.on the host
when I run the libusb executable on host, all the attached device are
listed, but the same when I run inside the container it says 0 devices are
attached.
Is there any other configuration I am missing. Please help.
Thanks & Regards,
Yasoda
---------- Forwarded message ----------
Date: Tue, 11 Sep 2018 12:04:45 +0300
Subject: Re: [lxc-users] How to provide device access to lxc unprivileged
containers ?
Greetings, Yasoda Padala!

Hi All,
I have a usb attached to my ubuntu machine (16.04) and trying to access
that device from unprivileged lxc container.
By access I mean, enumerate and do I/O on that device.

What for? If it's a block device, just mount it into container FS.

I have written a small program using libusb library and using that

libusb

executable to enumerate,read/write usb device from container
Please find attached lxc config file and libusb executable.
I have found plenty of examples in various forums but nothing worked

for me.

1. Added below entries in lxc config file
lxc.cgroup.devices.allow = b 8:* rwm
lxc.mount.entry = /dev/bus/usb/001/ dev/bus/usb/001/ none

bind,create=dir 0 0

lxc.mount.entry = /dev/sdc

/home/oxpd/.local/share/lxc/Test/rootfs/dev/sdc none bind,create=file 0 0

lxc.mount.entry = /dev/sdc1
/home/oxpd/.local/share/lxc/Test/rootfs/dev/sdc1 none bind,create=file

0 0

2. Changed device owner to 100000
3. changed device permission to 777.on the host
when I run the libusb executable on host, all the attached device are
listed, but the same when I run inside the container it says 0 devices

are attached.

Is there any other configuration I am missing. Please help.

--
With best regards,
Andrey Repin
Tuesday, September 11, 2018 12:04:14
Sorry for my terrible
english..._______________________________________________
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