This ensures each goroutine is given its own Netlink connection, and
presumably avoids having a message destined for one goroutine read by
another goroutine.
If in getCgroupPath in cgroups we have some other hierarchies after
"devices" using ".*" sometimes will cause matching wrong string as
a container path so we need negated character class here: "[^:]*".
e.g.
If cgroups string is
"153:name=systemd:/system.slice/docker-f55e7cad1fcc02f992e0c33c210ecdc6d641858a665f28370523c27c05bdde0e.scope,4:freezer,devices,name=container:/system.slice/docker-f55e7cad1fcc02f992e0c33c210ecdc6d641858a665f28370523c27c05bdde0e.scope,3:cpuacct,cpu,cpuset,name=fairsched:/system.slice/docker-f55e7cad1fcc02f992e0c33c210ecdc6d641858a665f28370523c27c05bdde0e.scope,2:memory:/system.slice/docker-f55e7cad1fcc02f992e0c33c210ecdc6d641858a665f28370523c27c05bdde0e.scope,1:blkio,name=beancounter:/system.slice/docker-f55e7cad1fcc02f992e0c33c210ecdc6d641858a665f28370523c27c05bdde0e.scope"
match[1] will be "blkio" but not:
/system.slice/docker-f55e7cad1fcc02f992e0c33c210ecdc6d641858a665f28370523c27c05bdde0e.scope
These fixes the commit:
4cbd91c761 Make getCgroupPath work in case of named or multi- hierarchies
v2: use negated character class, correct the example, remove .* on
either end as they don't do anything in FindSubmatch.
In case we have devices hierarchies mounted in named cgroup
or together with other hierarchy regexp parse will fail.
So after "devices" and before ":" can be name of cgroup or
other hierarchies names.
E.g.:
1) remount cgroups:
umount /sys/fs/cgroup/devices
mkdir /sys/fs/cgroup/named_cgroup
mount -n -t cgroup -o devices,name=named_cgroup cgroup
/sys/fs/cgroup/named_cgroup
2) add some task to nested device cgroup and check ps output
mkdir /sys/fs/cgroup/named_cgroup/test.slice
sleep 1000 &
[1] 22734
echo 22734 > /sys/fs/cgroup/named_cgroup/test.slice/tasks
ps -ao pid,cgroup | grep 22734
22734
14:devices,name=named_cgroup:/test.slice,1:name=systemd:/user.slice/user-1000.slice/session-1.scope
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Remove spec-related fields from stat.
We can simplify the stats a bit further by handling Int and Float better.
But this was big enough change already.
Verified v1 and v2 spec/stats/appmetrics APIs.
Docker does not provide the rootfs path through docker inspect or statefile
and the path is dependent on the storage driver being used.
Instead of enumerating the storage drivers, we pick a pid from the container
and get the config from /proc/pid/root. Although a bit expensive, this method
works for non-docker containers too.
