This adds a small C binary for fighting zombies. It is mounted under
`/dev/init` and is prepended to the args specified by the user. You
enable it via a daemon flag, `dockerd --init`, as it is disable by
default for backwards compat.
You can also override the daemon option or specify this on a per
container basis with `docker run --init=true|false`.
You can test this by running a process like this as the pid 1 in a
container and see the extra zombie that appears in the container as it
is running.
```c
int main(int argc, char ** argv) {
pid_t pid = fork();
if (pid == 0) {
pid = fork();
if (pid == 0) {
exit(0);
}
sleep(3);
exit(0);
}
printf("got pid %d and exited\n", pid);
sleep(20);
}
```
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
This device is not required by the OCI spec.
The rationale for this was linked to docker/docker#2393
So a non functional /dev/fuse was created, and actual fuse use still is
required to add the device explicitly. However even old versions of the JVM
on Ubuntu 12.04 no longer require the fuse package, and this is all not
needed.
See also https://github.com/opencontainers/runc/pull/983 although this
change alone stops the fuse device being created.
Tested and does not change actual ability to use fuse.
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
/proc/timer_list seems to leak information about the host. Here is
an example from a busybox container running on docker+kubernetes.
# cat /proc/timer_list | grep -i -e kube
<ffff8800b8cc3db0>, hrtimer_wakeup, S:01, futex_wait_queue_me, kubelet/2497
<ffff880129ac3db0>, hrtimer_wakeup, S:01, futex_wait_queue_me, kube-proxy/3478
<ffff8800b1b77db0>, hrtimer_wakeup, S:01, futex_wait_queue_me, kube-proxy/3470
<ffff8800bb6abdb0>, hrtimer_wakeup, S:01, futex_wait_queue_me, kubelet/2499
Signed-Off-By: Davanum Srinivas <davanum@gmail.com>
Signed-off-by: Davanum Srinivas <davanum@gmail.com>
This vendors in new spec/runc that supports
setting readonly and masked paths in the
configuration. Using this allows us to make an
exception for `—-privileged`.
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
