# docker run --rm -it alpine:3.8 /bin/sh
docker: Error response from daemon: unable to find "net_prio" in controller set: unknown.

Client:
 Version:           18.09.0
 API version:       1.39
 Go version:        go1.10.4
 Git commit:        4d60db4
 Built:             Wed Nov  7 00:57:21 2018
 OS/Arch:           linux/arm
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          18.09.0
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.4
  Git commit:       4d60db4
  Built:            Wed Nov  7 00:17:57 2018
  OS/Arch:          linux/arm
  Experimental:     true

Containers: 0
 Running: 0
 Paused: 0
 Stopped: 0
Images: 5
Server Version: 18.09.0
Storage Driver: btrfs
 Build Version: Btrfs v4.7.3
 Library Version: 101
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host ipvlan macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: active
 NodeID: jxgj5lhwlq7mep5e4jqx64frm
 Is Manager: true
 ClusterID: m10pfu1k75j8mvx5mqxjbb67n
 Managers: 3
 Nodes: 5
 Default Address Pool: 10.0.0.0/8
 SubnetSize: 24
 Orchestration:
  Task History Retention Limit: 5
 Raft:
  Snapshot Interval: 10000
  Number of Old Snapshots to Retain: 0
  Heartbeat Tick: 1
  Election Tick: 3
 Dispatcher:
  Heartbeat Period: 5 seconds
 CA Configuration:
  Expiry Duration: 3 months
  Force Rotate: 0
 Autolock Managers: false
 Root Rotation In Progress: false
 Node Address: 192.168.1.37
 Manager Addresses:
  192.168.1.33:2377
  192.168.1.34:2377
  192.168.1.37:2377
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: c4446665cb9c30056f4998ed953e6d4ff22c7c39
runc version: 4fc53a81fb7c994640722ac585fa9ca548971871
init version: fec3683
Security Options:
 seccomp
  Profile: default
Kernel Version: 4.19.13-v7+
Operating System: Raspbian GNU/Linux buster/sid
OSType: linux
Architecture: armv7l
CPUs: 4
Total Memory: 926.1MiB
Name: docker02
ID: KCJI:V4QV:M3ZZ:R5IU:R444:GNAX:3ORW:CEDK:V367:6X27:OHXC:VCVB
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: true
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false
Product License: Community Engine

WARNING: No swap limit support
WARNING: No cpu cfs quota support
WARNING: No cpu cfs period support

# ls -hl /sys/fs/cgroup/
total 0
dr-xr-xr-x 5 root root  0 Dec 21 19:53 blkio
lrwxrwxrwx 1 root root 11 Dec 21 19:53 cpu -> cpu,cpuacct
lrwxrwxrwx 1 root root 11 Dec 21 19:53 cpuacct -> cpu,cpuacct
dr-xr-xr-x 5 root root  0 Dec 21 19:53 cpu,cpuacct
dr-xr-xr-x 3 root root  0 Dec 21 19:53 cpuset
dr-xr-xr-x 5 root root  0 Dec 21 19:53 devices
dr-xr-xr-x 3 root root  0 Dec 21 19:53 freezer
dr-xr-xr-x 5 root root  0 Dec 21 19:53 memory
dr-xr-xr-x 3 root root  0 Dec 21 19:53 net_cls
lrwxrwxrwx 1 root root  7 Dec 21 19:53 net_prio -> net_cls
dr-xr-xr-x 6 root root  0 Dec 21 19:53 systemd
dr-xr-xr-x 5 root root  0 Dec 21 19:53 unified

# mount | grep cgroup
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)
cgroup2 on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/net_cls type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)