Runsc wants to mount /tmp using internal tmpfs implementation for
performance. However, it risks hiding files that may exist under
/tmp in case it's present in the container. Now, it only mounts
over /tmp iff:
- /tmp was not explicitly asked to be mounted
- /tmp is empty
If any of this is not true, then /tmp maps to the container's
image /tmp.
Note: checkpoint doesn't have sentry FS mounted to check if /tmp
is empty. It simply looks for explicit mounts right now.
PiperOrigin-RevId: 229607856
Change-Id: I10b6dae7ac157ef578efc4dfceb089f3b94cde06
And we need to wait a gofer process before cgroup.Uninstall,
because it is running in the sandbox cgroups.
PiperOrigin-RevId: 228904020
Change-Id: Iaf8826d5b9626db32d4057a1c505a8d7daaeb8f9
Each container has its respective gofer. Test that
gofer can be shutdown when a container stops and that
it doesn't affect other containers.
PiperOrigin-RevId: 220829898
Change-Id: I2a44a3cf2a88577e6ad1133afc622bbf4a5f6591
SetupContainerInRoot was setting Config.RootDir unnecessarily
and causing a --race violation in TestMultiContainerDestroyStarting.
PiperOrigin-RevId: 220580073
Change-Id: Ie0b28c19846106c7458a92681b708ae70f87d25a
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
--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
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 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
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
Fabricio Voznika
Andrei Vagin
Ian Gudger
Kevin Krakauer
Nicolas Lacasse
Lantao Liu