We now have one place that keeps track of (most) devices that are allowed and created within the container. That place is pkg/libcontainer/devices/devices.go
This fixes several inconsistencies between which devices were created in the lxc backend and the native backend. It also fixes inconsistencies between wich devices were created and which were allowed. For example, /dev/full was being created but it was not allowed within the cgroup. It also declares the file modes and permissions of the default devices, rather than copying them from the host. This is in line with docker's philosphy of not being host dependent.
Docker-DCO-1.1-Signed-off-by: Timothy Hobbs <timothyhobbs@seznam.cz> (github: https://github.com/timthelion)
Add specific types for Required and Optional DeviceNodes
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Without this any container startup fails:
2014/05/20 09:20:36 setup mount namespace copy additional dev nodes mknod fuse operation not permitted
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Fixes#5849
If the host system does not have fuse enabled in the kernel config we
will ignore the is not exist errors when trying to copy the device node
from the host system into the container.
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Some applications want to write to /proc. For instance:
docker run -it centos groupadd foo
Gives: groupadd: failure while writing changes to /etc/group
And strace reveals why:
open("/proc/self/task/13/attr/fscreate", O_RDWR) = -1 EROFS (Read-only file system)
I've looked at what other systems do, and systemd-nspawn makes /proc read-write
and /proc/sys readonly, while lxc allows "proc:mixed" which does the same,
plus it makes /proc/sysrq-trigger also readonly.
The later seems like a prudent idea, so we follows lxc proc:mixed.
Additionally we make /proc/irq and /proc/bus, as these seem to let
you control various hardware things.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
those that were specified in the config. This commit also explicitly
adds a set of capabilities that we were silently not dropping and were
assumed by the tests.
Docker-DCO-1.1-Signed-off-by: Victor Marmol <vmarmol@google.com> (github: vmarmol)
We don't need this because it is covered by the libcontainer MAINTAINERS
file
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
After copying allowed device nodes, set up "/dev/fd", "/dev/stdin",
"/dev/stdout", and "/dev/stderr" symlinks.
Docker-DCO-1.1-Signed-off-by: Bernerd Schaefer <bj.schaefer@gmail.com> (github: bernerdschaefer)
[rebased by @crosbymichael]
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Before we create any files to bind-mount on, make sure they are
inside the container rootfs, handling for instance absolute symbolic
links inside the container.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
All modern distros set up /run to be a tmpfs, see for instance:
https://wiki.debian.org/ReleaseGoals/RunDirectory
Its a very useful place to store pid-files, sockets and other things
that only live at runtime and that should not be stored in the image.
This is also useful when running systemd inside a container, as it
will try to mount /run if not already mounted, which will fail for
non-privileged container.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
If you specify a bind mount in a place that doesn't have a file yet we
create that (and parent directories). This is needed because otherwise
you can't use volumes like e.g. /dev/log, as that gets covered by the
/dev tmpfs mounts.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Timothy Hobbs
Michael Crosby
Erik Hollensbe
Vishnu Kannan
Michael Crosby
Victor Vieux
Victor Marmol
Victor Vieux
Tianon Gravi
Alexander Larsson
Sridhar Ratnakumar
Bernerd Schaefer
Guillaume J. Charmes
Rohit Jnagal