And allow cgroup mount take flags from user configs.
As we show ro in the recommendation, so hard-coded
read-only flag should be removed.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Fixes: https://github.com/docker/docker/issues/14543
Fixes: https://github.com/docker/docker/pull/14610
Before this, we got mount info in container:
```
sysfs /sys sysfs ro,seclabel,nosuid,nodev,noexec,relatime 0 0
/sys/fs/cgroup tmpfs rw,seclabel,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,relatime,cpuset 0 0
```
It has no mount source, so in `parseInfoFile` in Docker code,
we'll get:
```
Error found less than 3 fields post '-' in "84 83 0:41 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs rw,seclabel"
```
After this fix, we have mount info corrected:
```
sysfs /sys sysfs ro,seclabel,nosuid,nodev,noexec,relatime 0 0
tmpfs /sys/fs/cgroup tmpfs rw,seclabel,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,relatime,cpuset 0 0
```
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Alexander Morozov
Mrunal Patel
Qiang Huang
Michael Crosby