hack/dind: fix cgroup v2 evacuation with docker run --init

Evacuate all the processes in `/sys/fs/cgroup/cgroup.procs`, not just PID 1.

Before:
```console
$ docker run --rm --privileged --init $(docker build -q .) cat /sys/fs/cgroup/cgroup.subtree_control
sed: couldn't flush stdout: Device or resource busy
```

After:
```console
$ docker run --rm --privileged --init $(docker build -q .) cat /sys/fs/cgroup/cgroup.subtree_control
cpuset cpu io memory hugetlb pids rdma
```

Fix docker-library/docker issue 308

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
(cherry picked from commit 42b1175eda)
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
This commit is contained in:
Akihiro Suda 2021-04-27 17:56:41 +09:00
parent ce82693823
commit 21391bb7f7
No known key found for this signature in database
GPG key ID: 49524C6F9F638F1A

View file

@ -27,10 +27,11 @@ fi
# cgroup v2: enable nesting
if [ -f /sys/fs/cgroup/cgroup.controllers ]; then
# move the init process (PID 1) from the root group to the /init group,
# move the processes from the root group to the /init group,
# otherwise writing subtree_control fails with EBUSY.
# An error during moving non-existent process (i.e., "cat") is ignored.
mkdir -p /sys/fs/cgroup/init
echo 1 > /sys/fs/cgroup/init/cgroup.procs
xargs -rn1 < /sys/fs/cgroup/cgroup.procs > /sys/fs/cgroup/init/cgroup.procs || :
# enable controllers
sed -e 's/ / +/g' -e 's/^/+/' < /sys/fs/cgroup/cgroup.controllers \
> /sys/fs/cgroup/cgroup.subtree_control