Commit Graph

23 Commits

Author SHA1 Message Date
Kevin Krakauer bb88c187c5 runsc: Enable waiting on exited processes.
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
2018-09-17 16:25:24 -07:00
Kevin Krakauer 25add7b22b runsc: Fix stdin/out/err in multi-container mode.
Stdin/out/err weren't being sent to the sentry.

PiperOrigin-RevId: 213307171
Change-Id: Ie4b634a58b1b69aa934ce8597e5cc7a47a2bcda2
2018-09-17 11:31:28 -07:00
Lantao Liu bde2a91433 runsc: Support container signal/wait.
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
2018-09-13 16:38:03 -07:00
Kevin Krakauer 2eff1fdd06 runsc: Add exec flag that specifies where to save the sandbox-internal pid.
This is different from the existing -pid-file flag, which saves a host pid.

PiperOrigin-RevId: 212713968
Change-Id: I2c486de8dd5cfd9b923fb0970165ef7c5fc597f0
2018-09-12 15:23:35 -07:00
Nicolas Lacasse 6cc9b311af platform: Pass device fd into platform constructor.
We were previously openining the platform device (i.e. /dev/kvm) inside the
platfrom constructor (i.e. kvm.New).  This requires that we have RW access to
the platform device when constructing the platform.

However, now that the runsc sandbox process runs as user "nobody", it is not
able to open the platform device.

This CL changes the kvm constructor to take the platform device FD, rather than
opening the device file itself. The device file is opened outside of the
sandbox and passed to the sandbox process.

PiperOrigin-RevId: 212505804
Change-Id: I427e1d9de5eb84c84f19d513356e1bb148a52910
2018-09-11 13:09:46 -07:00
Nicolas Lacasse 9751b800a6 runsc: Support multi-container exec.
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
2018-09-07 17:39:54 -07:00
Kevin Krakauer 8f0b6e7fc0 runsc: Support runsc kill multi-container.
Now, we can kill individual containers rather than the entire sandbox.

PiperOrigin-RevId: 211748106
Change-Id: Ic97e91db33d53782f838338c4a6d0aab7a313ead
2018-09-05 21:14:56 -07:00
Nicolas Lacasse f96b33c73c runsc: Promote getExecutablePathInternal to getExecutablePath.
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
2018-09-05 13:01:21 -07:00
Fabricio Voznika db81c0b02f Put fsgofer inside chroot
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
2018-08-27 11:10:14 -07:00
Nicolas Lacasse 106de2182d runsc: Terminal support for "docker exec -ti".
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
2018-08-24 17:43:21 -07:00
Kevin Krakauer 635b0c4593 runsc fsgofer: Support dynamic serving of filesystems.
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
2018-08-15 16:25:22 -07:00
Fabricio Voznika 0d350aac7f Enable SACK in runsc
SACK is disabled by default and needs to be manually enabled. It not only
improves performance, but also fixes hangs downloading files from certain
websites.

PiperOrigin-RevId: 207906742
Change-Id: I4fb7277b67bfdf83ac8195f1b9c38265a0d51e8b
2018-08-08 10:26:18 -07:00
Justine Olshan c05660373e Moved restore code out of create and made to be called after create.
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
2018-07-18 16:58:30 -07:00
Kevin Krakauer 16d37973eb runsc: Add the "wait" subcommand.
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
2018-06-28 14:56:36 -07:00
Kevin Krakauer 04bdcc7b65 runsc: Enable waiting on individual containers within a sandbox.
PiperOrigin-RevId: 201742160
Change-Id: Ia9fa1442287c5f9e1196fb117c41536a80f6bb31
2018-06-22 14:31:25 -07:00
Fabricio Voznika 4ad7315b67 Add 'runsc debug' command
It prints sandbox stacks to the log to help debug stuckness. I expect
that many more options will be added in the future.

PiperOrigin-RevId: 201405931
Change-Id: I87e560800cd5a5a7b210dc25a5661363c8c3a16e
2018-06-20 13:31:31 -07:00
Kevin Krakauer 5397963b5d runsc: Enable container creation within existing sandboxes.
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
2018-06-19 21:44:33 -07:00
Justine Olshan a6dbef045f Added a resume command to unpause a paused container.
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
2018-06-19 15:23:36 -07:00
Justine Olshan 0786707cd9 Added code for a pause command for a container process.
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
2018-06-15 16:09:09 -07:00
Googler 722275c3d1 Added a function to the controller to checkpoint a container.
Functionality for checkpoint is not complete, more to come.

PiperOrigin-RevId: 199500803
Change-Id: Iafb0fcde68c584270000fea898e6657a592466f7
2018-06-06 11:43:55 -07:00
Nicolas Lacasse 31386185fe Push signal-delivery and wait into the sandbox.
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
2018-05-17 11:55:28 -07:00
Nicolas Lacasse 1bdec86bae Return better errors from Docker when runsc fails to start.
Two changes in this CL:

First, make the "boot" process sleep when it encounters an error to give the
controller time to send the error back to the "start" process. Otherwise the
"boot" process exits immediately and the control connection errors with EOF.

Secondly, open the log file with O_APPEND, not O_TRUNC. Docker uses the same
log file for all runtime commands, and setting O_TRUNC causes them to get
destroyed. Furthermore, containerd parses these log files in the event of an
error, and it does not like the file being truncated out from underneath it.

Now, when trying to run a binary that does not exist in the image, the error
message is more reasonable:

$ docker run alpine /not/found
docker: Error response from daemon: OCI runtime start failed: /usr/local/google/docker/runtimes/runscd did not terminate sucessfully: error starting sandbox: error starting application [/not/found]: failed to create init process: no such file or directory

Fixes #32

PiperOrigin-RevId: 196027084
Change-Id: Iabc24c0bdd8fc327237acc051a1655515f445e68
2018-05-09 14:13:37 -07:00
Googler d02b74a5dc Check in gVisor.
PiperOrigin-RevId: 194583126
Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463
2018-04-28 01:44:26 -04:00