We construct a dir with the executable bind-mounted at /exe, and proc mounted
at /proc. Runsc now executes the sandbox process inside this chroot, thus
limiting access to the host filesystem. The mounts and chroot dir are removed
when the sandbox is destroyed.
Because this requires bind-mounts, we can only do the chroot if we have
CAP_SYS_ADMIN.
PiperOrigin-RevId: 211994001
Change-Id: Ia71c515e26085e0b69b833e71691830148bc70d1
Now each container gets its own dedicated gofer that is chroot'd to the
rootfs path. This is done to add an extra layer of security in case the
gofer gets compromised.
PiperOrigin-RevId: 210396476
Change-Id: Iba21360a59dfe90875d61000db103f8609157ca0
This CL adds terminal support for "docker exec". We previously only supported
consoles for the container process, but not exec processes.
The SYS_IOCTL syscall was added to the default seccomp filter list, but only
for ioctls that get/set winsize and termios structs. We need to allow these
ioctl for all containers because it's possible to run "exec -ti" on a
container that was started without an attached console, after the filters
have been installed.
Note that control-character signals are still not properly supported.
Tested with:
$ docker run --runtime=runsc -it alpine
In another terminial:
$ docker exec -it <containerid> /bin/sh
PiperOrigin-RevId: 210185456
Change-Id: I6d2401e53a7697bb988c120a8961505c335f96d9
When multiple containers run inside a sentry, each container has its own root
filesystem and set of mounts. Containers are also added after sentry boot rather
than all configured and known at boot time.
The fsgofer needs to be able to serve the root filesystem of each container.
Thus, it must be possible to add filesystems after the fsgofer has already
started.
This change:
* Creates a URPC endpoint within the gofer process that listens for requests to
serve new content.
* Enables the sentry, when starting a new container, to add the new container's
filesystem.
* Mounts those new filesystems at separate roots within the sentry.
PiperOrigin-RevId: 208903248
Change-Id: Ifa91ec9c8caf5f2f0a9eead83c4a57090ce92068
9P socket was being created without CLOEXEC and was being inherited
by the children. This would prevent the gofer from detecting that the
sandbox had exited, because the socket would not be closed.
PiperOrigin-RevId: 199168959
Change-Id: I3ee1a07cbe7331b0aeb1cf2b697e728ce24f85a7
This is a necessary prerequisite for supporting multiple containers in a single
sandbox.
All the commands (in cmd package) now call operations on Containers (container
package). When a Container first starts, it will create a Sandbox with the same
ID.
The Sandbox class is now simpler, as it only knows how to create boot/gofer
processes, and how to forward commands into the running boot process.
There are TODOs sprinkled around for additional support for multiple
containers. Most notably, we need to detect when a container is intended to run
in an existing sandbox (by reading the metadata), and then have some way to
signal to the sandbox to start a new container. Other urpc calls into the
sandbox need to pass the container ID, so the sandbox can run the operation on
the given container. These are only half-plummed through right now.
PiperOrigin-RevId: 196688269
Change-Id: I1ecf4abbb9dd8987a53ae509df19341aaf42b5b0
Nicolas Lacasse
Fabricio Voznika
Kevin Krakauer
Googler