docker change cgroup driver to systemd

Question

I want Docker to start with systemd cgroup driver. For some reason it is using only cgroupfs on my CentOS 7 server.

Here is startup config file.

# systemctl cat docker
# /usr/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=http://docs.docker.com
After=network.target
Wants=docker-storage-setup.service
Requires=docker-cleanup.timer

[Service]
Type=notify
NotifyAccess=all
EnvironmentFile=-/etc/sysconfig/docker
EnvironmentFile=-/etc/sysconfig/docker-storage
EnvironmentFile=-/etc/sysconfig/docker-network
Environment=GOTRACEBACK=crash
Environment=DOCKER_HTTP_HOST_COMPAT=1
Environment=PATH=/usr/libexec/docker:/usr/bin:/usr/sbin
ExecStart=/usr/bin/dockerd-current \
          --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current \
          --default-runtime=docker-runc \
          --exec-opt native.cgroupdriver=systemd \
          --userland-proxy-path=/usr/libexec/docker/docker-proxy-current \
          $OPTIONS \
          $DOCKER_STORAGE_OPTIONS \
          $DOCKER_NETWORK_OPTIONS \
          $ADD_REGISTRY \
          $BLOCK_REGISTRY \
          $INSECURE_REGISTRY
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=1048576
LimitNPROC=1048576
LimitCORE=infinity
TimeoutStartSec=0
Restart=on-abnormal
MountFlags=slave

[Install]
WantedBy=multi-user.target

# /etc/systemd/system/docker.service.d/docker-thinpool.conf
 [Service]
 ExecStart=
 ExecStart=/usr/bin/dockerd --storage-driver=devicemapper --storage-opt=dm.thinpooldev=/dev/mapper/docker-thinpool \
 --storage-opt=dm.use_deferred_removal=true --storage-opt=dm.use_deferred_deletion=true
 EOF

When I start Docker, it's running like this:

# ps -fed | grep docker
root      8436     1  0 19:13 ?        00:00:00 /usr/bin/dockerd-current --storage-driver=devicemapper --storage-opt=dm.thinpooldev=/dev/mapper/docker-thinpool --storage-opt=dm.use_deferred_removal=true --storage-opt=dm.use_deferred_deletion=true
root      8439  8436  0 19:13 ?        00:00:00 /usr/bin/docker-containerd-current -l unix:///var/run/docker/libcontainerd/docker-containerd.sock --shim docker-containerd-shim --metrics-interval=0 --start-timeout 2m --state-dir /var/run/docker/libcontainerd/containerd --runtime docker-runc

Here is the output of docker info:

# docker info
Containers: 0
 Running: 0
 Paused: 0
 Stopped: 0
Images: 1
Server Version: 1.12.6
Storage Driver: devicemapper
 Pool Name: docker-thinpool
 Pool Blocksize: 524.3 kB
 Base Device Size: 10.74 GB
 Backing Filesystem: xfs
 Data file:
 Metadata file:
 Data Space Used: 185.6 MB
 Data Space Total: 1.015 GB
 Data Space Available: 829.4 MB
 Metadata Space Used: 77.82 kB
 Metadata Space Total: 8.389 MB
 Metadata Space Available: 8.311 MB
 Thin Pool Minimum Free Space: 101.2 MB
 Udev Sync Supported: true
 Deferred Removal Enabled: true
 Deferred Deletion Enabled: true
 Deferred Deleted Device Count: 0
 Library Version: 1.02.135-RHEL7 (2016-11-16)
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: null bridge overlay host
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Security Options: seccomp
Kernel Version: 3.10.0-514.16.1.el7.x86_64
Operating System: CentOS Linux 7 (Core)
OSType: linux
Architecture: x86_64
Number of Docker Hooks: 2
CPUs: 1
Total Memory: 992.7 MiB
Name: master
ID: 6CFR:H7SN:MEU7:PNJH:UMSO:6MNE:43Q5:SF4K:Z25I:BKHP:53U4:63SO
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Insecure Registries:
 127.0.0.0/8
Registries: docker.io (secure)

How can I make it run with systemd?

Thanks SR

Answer 1

A solution that does not involve editing systemd units or drop-ins would be to create (or edit) the /etc/docker/daemon.json configuration file and to include the following:

{
  "exec-opts": ["native.cgroupdriver=systemd"]
}

After saving it, restart your docker service.

sudo systemctl restart docker

This solution obviously is only feasible if you would want to apply this system-wide.

Answer 2

Since I have two configuration file I need to add the entry in the second config file also -- /etc/systemd/system/docker.service.d/docker-thinpool.conf:

--exec-opt native.cgroupdriver=systemd \