'docker exec' was getting CAP_NET_RAW even when --net-raw=false
because it was not filtered out from when copying container's
capabilities.
PiperOrigin-RevId: 272260451
This is done because the root container for CRI is the infrastructure (pause)
container and always gets a low oom_score_adj. We do this to ensure that only
the oom_score_adj of user containers is used to calculated the sandbox
oom_score_adj.
Implemented in runsc rather than the containerd shim as it's a bit cleaner to
implement here (in the shim it would require overwriting the oomScoreAdj and
re-writing out the config.json again). This processing is Kubernetes(CRI)
specific but we are currently only supporting CRI for multi-container support
anyway.
PiperOrigin-RevId: 267507706
Each gofer now has a goroutine that polls on the FDs used
to communicate with the sandbox. The respective gofer is
destroyed if any of the FDs is closed.
Closes#601
PiperOrigin-RevId: 261383725
Addresses obvious typos, in the documentation only.
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/443 from Pixep:fix/documentation-spelling 4d0688164eafaf0b3010e5f4824b35d1e7176d65
PiperOrigin-RevId: 255477779
Based on the guidelines at
https://opensource.google.com/docs/releasing/authors/.
1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./'
2. Manual fixup of "Google Inc" references.
3. Add AUTHORS file. Authors may request to be added to this file.
4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS.
Fixes#209
PiperOrigin-RevId: 245823212
Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
Properly handle propagation options for root and mounts. Now usage of
mount options shared, rshared, and noexec cause error to start. shared/
rshared breaks sandbox=>host isolation. slave however can be supported
because changes propagate from host to sandbox.
Root FS setup moved inside the gofer. Apart from simplifying the code,
it keeps all mounts inside the namespace. And they are torn down when
the namespace is destroyed (DestroyFS is no longer needed).
PiperOrigin-RevId: 239037661
Change-Id: I8b5ee4d50da33c042ea34fa68e56514ebe20e6e0
The original code assumed that it was safe to join and not restore cgroup,
but Container.Run will not exit after calling start, making cgroup cleanup
fail because there were still processes inside the cgroup.
PiperOrigin-RevId: 228529199
Change-Id: I12a48d9adab4bbb02f20d71ec99598c336cbfe51
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 is a breaking change if you're using --debug-log-dir.
The fix is to replace it with --debug-log and add a '/' at
the end:
--debug-log-dir=/tmp/runsc ==> --debug-log=/tmp/runsc/
PiperOrigin-RevId: 216761212
Change-Id: I244270a0a522298c48115719fa08dad55e34ade1
Sandbox creation uses the limits and reservations configured in the
OCI spec and set cgroup options accordinly. Then it puts both the
sandbox and gofer processes inside the cgroup.
It also allows the cgroup to be pre-configured by the caller. If the
cgroup already exists, sandbox and gofer processes will join the
cgroup but it will not modify the cgroup with spec limits.
PiperOrigin-RevId: 216538209
Change-Id: If2c65ffedf55820baab743a0edcfb091b89c1019
Capabilities.Set() adds capabilities,
but doesn't remove existing ones that might have been loaded. Fixed
the code and added tests.
PiperOrigin-RevId: 213726369
Change-Id: Id7fa6fce53abf26c29b13b9157bb4c6616986fba
We must use a context.Context with a Root Dirent that corresponds to the
container's chroot. Previously we were using the root context, which does not
have a chroot.
Getting the correct context required refactoring some of the path-lookup code.
We can't lookup the path without a context.Context, which requires
kernel.CreateProcArgs, which we only get inside control.Execute. So we have to
do the path lookup much later than we previously were.
PiperOrigin-RevId: 212064734
Change-Id: I84a5cfadacb21fd9c3ab9c393f7e308a40b9b537
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
Remove GetExecutablePath (the non-internal version). This makes path handling
more consistent between exec, root, and child containers.
The new getExecutablePath now uses MountNamespace.FindInode, which is more
robust than Walking the Dirent tree ourselves.
This also removes the last use of lstat(2) in the sentry, so that can be
removed from the filters.
PiperOrigin-RevId: 211683110
Change-Id: Ic8ec960fc1c267aa7d310b8efe6e900c88a9207a
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
Previously, runsc improperly attempted to find an executable in the container's
PATH.
We now search the PATH via the container's fsgofer rather than the host FS,
eliminating the confusing differences between paths on the host and within a
container.
PiperOrigin-RevId: 210159488
Change-Id: I228174dbebc4c5356599036d6efaa59f28ff28d2
Previously, error message only showed "<nil>" when child and pid were the
same (since no error is returned by the Wait4 syscall in this case) which
occurs when the process has incorrectly terminated. A new error message
was added to improve clarity for such a case. Tests for this function were
modified to reflect the improved distinction between process termination
and error.
PiperOrigin-RevId: 204018107
Change-Id: Ib38481c9590405e5bafcb6efe27fd49b3948910c
Updated how restoring occurs through boot.go with a separate Restore function.
This prevents a new process and new mounts from being created.
Added tests to ensure the container is restored.
Registered checkpoint and restore commands so they can be used.
Docker support for these commands is still limited.
Working on #80.
PiperOrigin-RevId: 202710950
Change-Id: I2b893ceaef6b9442b1ce3743bd112383cb92af0c
Containers are created as processes in the sandbox. Of the many things that
don't work yet, the biggest issue is that the fsgofer is launched with its root
as the sandbox's root directory. Thus, when a container is started and wants to
read anything (including the init binary of the container), the gofer tries to
serve from sandbox's root (which basically just has pause), not the container's.
PiperOrigin-RevId: 201294560
Change-Id: I6423aa8830538959c56ae908ce067e4199d627b1
Common code to setup and run sandbox is moved to testutil. Also, don't
link "boot" and "gofer" commands with test binary. Instead, use runsc
binary from the build. This not only make the test setup simpler, but
also resolves a dependency issue with sandbox_tests not depending on
container package.
PiperOrigin-RevId: 199164478
Change-Id: I27226286ca3f914d4d381358270dd7d70ee8372f
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