If the sandbox process is dead (because of a panic or some other problem),
container.Destroy will never remove the container metadata file, since it will
always fail when calling container.stop().
This CL changes container.Destroy() to always perform the three necessary
cleanup operations:
* Stop the sandbox and gofer processes.
* Remove the container fs on the host.
* Delete the container metadata directory.
Errors from these three operations will be concatenated and returned from
Destroy().
PiperOrigin-RevId: 225448164
Change-Id: I99c6311b2e4fe5f6e2ca991424edf1ebeae9df32
sandbox.Wait is racey, as the sandbox may have exited before it is called, or
even during.
We already had code to handle the case that the sandbox exits during the Wait
call, but we were not properly handling the case where the sandbox has exited
before the call.
The best we can do in such cases is return the sandbox exit code as the
application exit code.
PiperOrigin-RevId: 221702517
Change-Id: I290d0333cc094c7c1c3b4ce0f17f61a3e908d787
Before this change, a container starting up could race with
destroy (aka delete) and leave processes behind.
Now, whenever a container is created, Loader.processes gets
a new entry. Start now expects the entry to be there, and if
it's not it means that the container was deleted.
I've also fixed Loader.waitPID to search for the process using
the init process's PID namespace.
We could use a few more tests for signal and wait. I'll send
them in another cl.
PiperOrigin-RevId: 220224290
Change-Id: I15146079f69904dc07d43c3b66cc343a2dab4cc4
Otherwise the gofer's attach point may be different from sandbox when there
symlinks in the path.
PiperOrigin-RevId: 219730492
Change-Id: Ia9c4c2d16228c6a1a9e790e0cb673fd881003fe1
Errors are shown as being ignored by assigning to the blank identifier.
PiperOrigin-RevId: 218103819
Change-Id: I7cc7b9d8ac503a03de5504ebdeb99ed30a531cf2
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
--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
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
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
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
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
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
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
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
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
Nicolas Lacasse
Fabricio Voznika
Ian Lewis
Ian Gudger
Kevin Krakauer
Lantao Liu
Justine Olshan
Brielle Broder