It's hard to resolve symlinks inside the sandbox because rootfs and mounts
may be read-only, forcing us to create mount points inside lower layer of an
overlay, **before** the volumes are mounted.
Since the destination must already be resolved outside the sandbox when creating
mounts, take this opportunity to rewrite the spec with paths resolved.
"runsc boot" will use the "resolved" spec to load mounts. In addition, symlink
traversals were disabled while mounting containers inside the sandbox.
It haven't been able to write a good test for it. So I'm relying on manual tests
for now.
PiperOrigin-RevId: 217749904
Change-Id: I7ac434d5befd230db1488446cda03300cc0751a9
This change introduces a new flags to create/run called
--user-log. Logs to this files are visible to users and
are meant to help debugging problems with their images
and containers.
For now only unsupported syscalls are sent to this log,
and only minimum support was added. We can build more
infrastructure around it as needed.
PiperOrigin-RevId: 216735977
Change-Id: I54427ca194604991c407d49943ab3680470de2d0
This is a prereq for running the sandbox process as user "nobody", when it may
not have permissions to open these files.
Instead, we must open then before starting the sandbox process, and pass them
by FD.
The specutils.ReadSpecFromFile method was fixed to always seek to the beginning
of the file before reading. This allows Files from the same FD to be read
multiple times, as we do in the boot command when the apply-caps flag is set.
Tested with --network=host.
PiperOrigin-RevId: 211570647
Change-Id: I685be0a290aa7f70731ebdce82ebc0ebcc9d475c
This is a prereq for running the sandbox process as user "nobody", when it may
not have permissions to open these files.
Instead, we must open then before starting the sandbox process, and pass them
by FD.
PiperOrigin-RevId: 210995199
Change-Id: I715875a9553290b4a49394a8fcd93be78b1933dd
Docker expects containers to be created before they are restored.
However, gVisor restoring requires specificactions regarding the kernel
and the file system. These actions were originally in booting the sandbox.
Now setting up the file system is deferred until a call to a call to
runsc start. In the restore case, the kernel is destroyed and a new kernel
is created in the same process, as we need the same process for Docker.
These changes required careful execution of concurrent processes which
required the use of a channel.
Full docker integration still needs the ability to restore into the same
container.
PiperOrigin-RevId: 205161441
Change-Id: Ie1d2304ead7e06855319d5dc310678f701bd099f
Restore creates a new container and uses the given image-path to load a saved
image of a previous container. Restore command is plumbed through container
and sandbox. This command does not work yet - more to come.
PiperOrigin-RevId: 201541229
Change-Id: I864a14c799ce3717d99bcdaaebc764281863d06f
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
Googler
Ian Gudger
Fabricio Voznika
Nicolas Lacasse
Justine Olshan
Brielle Broder