Now containers run with "docker run -it" support control characters like ^C and
^Z.
This required refactoring our signal handling a bit. Signals delivered to the
"runsc boot" process are turned into loader.Signal calls with the appropriate
delivery mode. Previously they were always sent directly to PID 1.
PiperOrigin-RevId: 217566770
Change-Id: I5b7220d9a0f2b591a56335479454a200c6de8732
--pid allows specific processes to be signalled rather than the container root
process or all processes in the container. containerd needs to SIGKILL exec'd
processes that timeout and check whether processes are still alive.
PiperOrigin-RevId: 217547636
Change-Id: I2058ebb548b51c8eb748f5884fb88bad0b532e45
It's possible for Start() and Wait() calls to race, if the sandboxed
application is short-lived. If the application finishes before (or during) the
Wait RPC, then Wait will fail. In practice this looks like "connection
refused" or "EOF" errors when waiting for an RPC response.
This race is especially bad in tests, where we often run "true" inside a
sandbox.
This CL does a best-effort fix, by returning the sandbox exit status as the
container exit status. In most cases, these are the same.
This fixes the remaining flakes in runsc/container:container_test.
PiperOrigin-RevId: 216777793
Change-Id: I9dfc6e6ec885b106a736055bc7a75b2008dfff7a
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
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
This can happen if an error is encountered during Create() which causes the
container to be destroyed and set to state Stopped.
Without this transition, errors during Create get hidden by the later panic.
PiperOrigin-RevId: 215599193
Change-Id: Icd3f42e12c685cbf042f46b3929bccdf30ad55b0
We add an additional (2^3)-1=7 processes, but the code was only waiting for 3.
I switched back to Math.Pow format to make the arithmetic easier to inspect.
PiperOrigin-RevId: 215588140
Change-Id: Iccad4d6f977c1bfc5c4b08d3493afe553fe25733
Terminal support in runsc relies on host tty file descriptors that are imported
into the sandbox. Application tty ioctls are sent directly to the host fd.
However, those host tty ioctls are associated in the host kernel with a host
process (in this case runsc), and the host kernel intercepts job control
characters like ^C and send signals to the host process. Thus, typing ^C into a
"runsc exec" shell will send a SIGINT to the runsc process.
This change makes "runsc exec" handle all signals, and forward them into the
sandbox via the "ContainerSignal" urpc method. Since the "runsc exec" is
associated with a particular container process in the sandbox, the signal must
be associated with the same container process.
One big difficulty is that the signal should not necessarily be sent to the
sandbox process started by "exec", but instead must be sent to the foreground
process group for the tty. For example, we may exec "bash", and from bash call
"sleep 100". A ^C at this point should SIGINT sleep, not bash.
To handle this, tty files inside the sandbox must keep track of their
foreground process group, which is set/get via ioctls. When an incoming
ContainerSignal urpc comes in, we look up the foreground process group via the
tty file. Unfortunately, this means we have to expose and cache the tty file in
the Loader.
Note that "runsc exec" now handles signals properly, but "runs run" does not.
That will come in a later CL, as this one is complex enough already.
Example:
root@:/usr/local/apache2# sleep 100
^C
root@:/usr/local/apache2# sleep 100
^Z
[1]+ Stopped sleep 100
root@:/usr/local/apache2# fg
sleep 100
^C
root@:/usr/local/apache2#
PiperOrigin-RevId: 215334554
Change-Id: I53cdce39653027908510a5ba8d08c49f9cf24f39
In order to implement kill --all correctly, the Sentry needs
to track all tasks that belong to a given container. This change
introduces ContainerID to the task, that gets inherited by all
children. 'kill --all' then iterates over all tasks comparing the
ContainerID field to find all processes that need to be signalled.
PiperOrigin-RevId: 214841768
Change-Id: I693b2374be8692d88cc441ef13a0ae34abf73ac6
This was done so it's easier to add more functionality
to this file for other tests.
PiperOrigin-RevId: 214782043
Change-Id: I1f38b9ee1219b3ce7b789044ada8e52bdc1e6279
Each container has associated metadata (particularly the container status) that
is manipulated by various runsc commands. This metadata is stored in a file
identified by the container id.
Different runsc processes may manipulate the same container metadata, and each
will read/write to the metadata file.
This CL adds a file lock per container which must be held when reading the
container metadata file, and when modifying and writing the container metadata.
PiperOrigin-RevId: 214019179
Change-Id: Ice4390ad233bc7f216c9a9a6cf05fb456c9ec0ad
I've made several attempts to create a test, but the lack of
permission from the test user makes it nearly impossible to
test anything useful.
PiperOrigin-RevId: 213922174
Change-Id: I5b502ca70cb7a6645f8836f028fb203354b4c625
This method will:
1. Stop the container process if it is still running.
2. Unmount all sanadbox-internal mounts for the container.
3. Delete the contaner root directory inside the sandbox.
Destroy is idempotent, and safe to call concurrantly.
This fixes a bug where after stopping a container, we cannot unmount the
container root directory on the host. This bug occured because the sandbox
dirent cache was holding a dirent with a host fd corresponding to a file inside
the container root on the host. The dirent cache did not know that the
container had exited, and kept the FD open, preventing us from unmounting on
the host.
Now that we unmount (and flush) all container mounts inside the sandbox, any
host FDs donated by the gofer will be closed, and we can unmount the container
root on the host.
PiperOrigin-RevId: 213737693
Change-Id: I28c0ff4cd19a08014cdd72fec5154497e92aacc9
For my own sanitity when thinking about possible transitions and state.
PiperOrigin-RevId: 213559482
Change-Id: I25588c86cf6098be4eda01f4e7321c102ceef33c
Reap children more systematically in container tests. Previously,
container_test was taking ~5 mins to run because constainer.Destroy()
would timeout waiting for the sandbox process to exit. Now the test
running in less than a minute.
Also made the contract around Container and Sandbox destroy clearer.
PiperOrigin-RevId: 213527471
Change-Id: Icca84ee1212bbdcb62bdfc9cc7b71b12c6d1688d
This makes `runsc wait` behave more like waitpid()/wait4() in that:
- Once a process has run to completion, you can wait on it and get its exit
code.
- Processes not waited on will consume memory (like a zombie process)
PiperOrigin-RevId: 213358916
Change-Id: I5b5eca41ce71eea68e447380df8c38361a4d1558
This CL:
1) Fix `runsc wait`, it now also works after the container exits;
2) Generate correct container state in Load;
2) Make sure `Destory` cleanup everything before successfully return.
PiperOrigin-RevId: 212900107
Change-Id: Ie129cbb9d74f8151a18364f1fc0b2603eac4109a
This is different from the existing -pid-file flag, which saves a host pid.
PiperOrigin-RevId: 212713968
Change-Id: I2c486de8dd5cfd9b923fb0970165ef7c5fc597f0
It was used before gofer was implemented and it's not
supported anymore.
BREAKING CHANGE: proxy-shared and proxy-exclusive options
are now: shared and exclusive.
PiperOrigin-RevId: 212017643
Change-Id: If029d4073fe60583e5ca25f98abb2953de0d78fd
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, we can kill individual containers rather than the entire sandbox.
PiperOrigin-RevId: 211748106
Change-Id: Ic97e91db33d53782f838338c4a6d0aab7a313ead
With multi-gofers, bind mounts in sub-containers should
just work. Removed restrictions and added test. There are
also a few cleanups along the way, e.g. retry unmounting
in case cleanup races with gofer teardown.
PiperOrigin-RevId: 211699569
Change-Id: Ic0a69c29d7c31cd7e038909cc686c6ac98703374
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
For readonly filesystems specified via relative path, we were forgetting to
mount relative to the container's bundle directory.
PiperOrigin-RevId: 210483388
Change-Id: I84809fce4b1f2056d0e225547cb611add5f74177
When revalidating a Dirent, if the inode id is the same, then we don't need to
throw away the entire Dirent. We can just update the unstable attributes in
place.
If the inode id has changed, then the remote file has been deleted or moved,
and we have no choice but to throw away the dirent we have a look up another.
In this case, we may still end up losing a mounted dirent that is a child of
the revalidated dirent. However, that seems appropriate here because the entire
mount point has been pulled out from underneath us.
Because gVisor's overlay is at the Inode level rather than the Dirent level, we
must pass the parent Inode and name along with the Inode that is being
revalidated.
PiperOrigin-RevId: 210431270
Change-Id: I705caef9c68900234972d5aac4ae3a78c61c7d42
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
The bug was caused by os.File's finalizer, which closes the file. Because
fsgofer.serve() was passed a file descriptor as an int rather than a os.File,
callers would pass os.File.Fd(), and the os.File would go out of scope. Thus,
the file would get GC'd and finalized nondeterministically, causing failures
when the file was used.
PiperOrigin-RevId: 209861834
Change-Id: Idf24d5c1f04c9b28659e62c97202ab3b4d72e994
UDS has a lower size limit than regular files. When running under bazel
this limit is exceeded. Test was changed to always mount /tmp and use
it for the test.
PiperOrigin-RevId: 209717830
Change-Id: I1dbe19fe2051ffdddbaa32b188a9167f446ed193
Tests get a readonly rootfs mapped to / (which was the case before)
and writable TEST_TMPDIR. This makes it easier to setup containers to
write to files and to share state between test and containers.
PiperOrigin-RevId: 209453224
Change-Id: I4d988e45dc0909a0450a3bb882fe280cf9c24334
Bazel adds the build type in front of directories making it hard to
refer to binaries in code.
PiperOrigin-RevId: 209010854
Change-Id: I6c9da1ac3bbe79766868a3b14222dd42d03b4ec5
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
Previously, gofer filesystems were configured with the default "fscache"
policy, which caches filesystem metadata and contents aggressively. While this
setting is best for performance, it means that changes from inside the sandbox
may not be immediately propagated outside the sandbox, and vice-versa.
This CL changes volumes and the root fs configuration to use a new
"remote-revalidate" cache policy which tries to retain as much caching as
possible while still making fs changes visible across the sandbox boundary.
This cache policy is enabled by default for the root filesystem. The default
value for the "--file-access" flag is still "proxy", but the behavior is
changed to use the new cache policy.
A new value for the "--file-access" flag is added, called "proxy-exclusive",
which turns on the previous aggressive caching behavior. As the name implies,
this flag should be used when the sandbox has "exclusive" access to the
filesystem.
All volume mounts are configured to use the new cache policy, since it is
safest and most likely to be correct. There is not currently a way to change
this behavior, but it's possible to add such a mechanism in the future. The
configurability is a smaller issue for volumes, since most of the expensive
application fs operations (walking + stating files) will likely served by the
root fs.
PiperOrigin-RevId: 208735037
Change-Id: Ife048fab1948205f6665df8563434dbc6ca8cfc9
Previously, processes which used file-system Unix Domain Sockets could not be
checkpoint-ed in runsc because the sockets were saved with their inode
numbers which do not necessarily remain the same upon restore. Now,
the sockets are also saved with their paths so that the new inodes
can be determined for the sockets based on these paths after restoring.
Tests for cases with UDS use are included. Test cleanup to come.
PiperOrigin-RevId: 208268781
Change-Id: Ieaa5d5d9a64914ca105cae199fd8492710b1d7ec
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
We must delete the output file at the beginning of the test, otherwise the test
fails immediately.
Also some minor cleanups in readOutputFile.
PiperOrigin-RevId: 205150525
Change-Id: I6bae1acd5b315320a2c6e25a59afcfc06267fb17
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
The leave-running flag allows the container to continue running after a
checkpoint has occurred by doing an immediate restore into a new
container with the same container ID after the old container is destroyed.
Updates #80.
PiperOrigin-RevId: 202695426
Change-Id: Iac50437f5afda018dc18b24bb8ddb935983cf336
Users can now call "runsc wait <container id>" to wait on a particular process
inside the container. -pid can also be used to wait on a specific PID.
Manually tested the wait subcommand for a single waiter and multiple waiters
(simultaneously 2 processes waiting on the container and 2 processes waiting on
a PID within the container).
PiperOrigin-RevId: 202548978
Change-Id: Idd507c2cdea613c3a14879b51cfb0f7ea3fb3d4c
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
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
Resume checks the status of the container and unpauses the kernel
if its status is paused. Otherwise nothing happens.
Tests were added to ensure that the process is in the correct state
after various commands.
PiperOrigin-RevId: 201251234
Change-Id: Ifd11b336c33b654fea6238738f864fcf2bf81e19
Like runc, the pause command will pause the processes of the given container.
It will set that container's status to "paused."
A resume command will be be added to unpause and continue running the process.
PiperOrigin-RevId: 200789624
Change-Id: I72a5d7813d90ecfc4d01cc252d6018855016b1ea
This is the first iteration of checkpoint that actually saves to a file.
Tests for checkpoint are included.
Ran into an issue when private unix sockets are enabled. An error message
was added for this case and the mutex state was set.
PiperOrigin-RevId: 200269470
Change-Id: I28d29a9f92c44bf73dc4a4b12ae0509ee4070e93
Just a UI/usability addition. It's a lot easier to type "60" than
"60185c721d7e10c00489f1fa210ee0d35c594873d6376b457fb1815e4fdbfc2c".
PiperOrigin-RevId: 199547932
Change-Id: I19011b5061a88aba48a9ad7f8cf954a6782de854
Checkpoint command is plumbed through container and sandbox.
Restore has also been added but it is only a stub. None of this
works yet. More changes to come.
PiperOrigin-RevId: 199510105
Change-Id: Ibd08d57f4737847eb25ca20b114518e487320185
Containerd will start deleting container and rootfs after container
is stopped. However, if gofer is still running, rootfs cleanup will
fail because of device busy.
This CL makes sure that gofer is not running when container state is
stopped.
Change from: lantaol@google.com
PiperOrigin-RevId: 199172668
Change-Id: I9d874eec3ecf74fd9c8edd7f62d9f998edef66fe
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 addresses the first issue reported in #59. CRI-O expects runsc to
return success to delete when --force is used with a non-existing container.
PiperOrigin-RevId: 198487418
Change-Id: If7660e8fdab1eb29549d0a7a45ea82e20a1d4f4a
Container user might not have enough priviledge to walk directories and
mount filesystems. Instead, create superuser to perform these steps of
the configuration.
PiperOrigin-RevId: 197953667
Change-Id: I643650ab654e665408e2af1b8e2f2aa12d58d4fb
This is another step towards multi-container support.
Previously, we delivered signals directly to the sandbox process (which then
forwarded the signal to PID 1 inside the sandbox). Similarly, we waited on a
container by waiting on the sandbox process itself. This approach will not work
when there are multiple containers inside the sandbox, and we need to
signal/wait on individual containers.
This CL adds two new messages, ContainerSignal and ContainerWait. These
messages include the id of the container to signal/wait. The controller inside
the sandbox receives these messages and signals/waits on the appropriate
process inside the sandbox.
The container id is plumbed into the sandbox, but it currently is not used. We
still end up signaling/waiting on PID 1 in all cases. Once we actually have
multiple containers inside the sandbox, we will need to keep some sort of map
of container id -> pid (or possibly pid namespace), and signal/kill the
appropriate process for the container.
PiperOrigin-RevId: 197028366
Change-Id: I07b4d5dc91ecd2affc1447e6b4bdd6b0b7360895
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