[root@localhost /]# uname -r
3.10.0-327.el7.x86_64

yum -y install docker

[root@localhost /]# systemctl start docker
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.

[root@localhost /]# systemctl status docker.service
● docker.service - Docker Application Container EngineLoaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)Active: failed (Result: exit-code) since 五 2018-04-20 06:50:52 CST; 3min 57s agoDocs: http://docs.docker.comProcess: 44005 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 --seccomp-profile=/etc/docker/seccomp.json $OPTIONS $DOCKER_STORAGE_OPTIONS $DOCKER_NETWORK_OPTIONS $ADD_REGISTRY $BLOCK_REGISTRY $INSECURE_REGISTRY $REGISTRIES (code=exited, status=1/FAILURE)Main PID: 44005 (code=exited, status=1/FAILURE)4月 20 06:50:50 localhost.localdomain systemd[1]: Starting Docker Application Container Engine...
4月 20 06:50:50 localhost.localdomain dockerd-current[44005]: time="2018-04-20T06:50:50.921964698+08:00" level=warning msg="could not ...ound"
4月 20 06:50:50 localhost.localdomain dockerd-current[44005]: time="2018-04-20T06:50:50.927241794+08:00" level=info msg="libcontainerd...4010"
4月 20 06:50:51 localhost.localdomain dockerd-current[44005]: time="2018-04-20T06:50:51.936045098+08:00" level=warning msg="overlay2: the b...
4月 20 06:50:52 localhost.localdomain dockerd-current[44005]: Error starting daemon: SELinux is not supported with the overlay2 graph ...alse)
4月 20 06:50:52 localhost.localdomain systemd[1]: docker.service: main process exited, code=exited, status=1/FAILURE
4月 20 06:50:52 localhost.localdomain systemd[1]: Failed to start Docker Application Container Engine.
4月 20 06:50:52 localhost.localdomain systemd[1]: Unit docker.service entered failed state.
4月 20 06:50:52 localhost.localdomain systemd[1]: docker.service failed.
Hint: Some lines were ellipsized, use -l to show in full.

[root@localhost /]# vi /etc/sysconfig/docker

# Modify these options if you want to change the way the docker daemon runs
OPTIONS='--selinux-enabled=false --log-driver=journald --signature-verification=false'
if [ -z "${DOCKER_CERT_PATH}" ]; thenDOCKER_CERT_PATH=/etc/docker
fi# Do not add registries in this file anymore. Use /etc/containers/registries.conf
# from the atomic-registries package.
#

[root@localhost /]# service docker start
Redirecting to /bin/systemctl start docker.service
[root@localhost /]# docker info
Containers: 0Running: 0Paused: 0Stopped: 0
Images: 0
Server Version: 1.13.1
Storage Driver: overlay2Backing Filesystem: xfsSupports d_type: falseNative Overlay Diff: false
Logging Driver: journald
Cgroup Driver: systemd
Plugins: Volume: localNetwork: bridge host macvlan null overlay
Swarm: inactive
Runtimes: docker-runc runc
Default Runtime: docker-runc
Init Binary: docker-init
containerd version:  (expected: aa8187dbd3b7ad67d8e5e3a15115d3eef43a7ed1)
runc version: N/A (expected: 9df8b306d01f59d3a8029be411de015b7304dd8f)
init version: N/A (expected: 949e6facb77383876aeff8a6944dde66b3089574)
Security Options:seccompWARNING: You're not using the default seccomp profileProfile: /etc/docker/seccomp.json
Kernel Version: 3.10.0-327.el7.x86_64
Operating System: CentOS Linux 7 (Core)
OSType: linux
Architecture: x86_64
Number of Docker Hooks: 3
CPUs: 1
Total Memory: 977.9 MiB
Name: localhost.localdomain
ID: 2QP3:PYDM:BLLS:P5QS:QGJN:N7GK:DAKV:ZWFG:FW54:FHS4:FCAN:6NR4
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
Experimental: false
Insecure Registries:127.0.0.0/8
Live Restore Enabled: false
Registries: docker.io (secure)

[root@localhost /]# docker run hello-world
Unable to find image 'hello-world:latest' locally
Trying to pull repository docker.io/library/hello-world ...
latest: Pulling from docker.io/library/hello-world
/usr/bin/docker-current: Get https://registry-1.docker.io/v2/library/hello-world/manifests/sha256:d5c74e6f8efc7bdf42a5e22bd764400692cf82360d86b8c587a7584b03f51520: Get https://auth.docker.io/token?scope=repository%3Alibrary%2Fhello-world%3Apull&service=registry.docker.io: net/http: request canceled (Client.Timeout exceeded while awaiting headers).
See '/usr/bin/docker-current run --help'.
[root@localhost /]# docker run hello-world
Unable to find image 'hello-world:latest' locally
Trying to pull repository docker.io/library/hello-world ...
latest: Pulling from docker.io/library/hello-world
9bb5a5d4561a: Pull complete
Digest: sha256:f5233545e43561214ca4891fd1157e1c3c563316ed8e237750d59bde73361e77
Status: Downloaded newer image for docker.io/hello-world:latestHello from Docker!
This message shows that your installation appears to be working correctly.To generate this message, Docker took the following steps:1. The Docker client contacted the Docker daemon.2. The Docker daemon pulled the "hello-world" image from the Docker Hub.(amd64)3. The Docker daemon created a new container from that image which runs theexecutable that produces the output you are currently reading.4. The Docker daemon streamed that output to the Docker client, which sent itto your terminal.To try something more ambitious, you can run an Ubuntu container with:$ docker run -it ubuntu bashShare images, automate workflows, and more with a free Docker ID:https://hub.docker.com/

For more examples and ideas, visit:https://docs.docker.com/engine/userguide/

[hongdada@localhost home]$ systemctl stop docker.service
==== AUTHENTICATING FOR org.freedesktop.systemd1.manage-units ===
Authentication is required to manage system services or units.
Authenticating as: root
Password:
==== AUTHENTICATION COMPLETE ===
[hongdada@localhost home]$ systemctl restart docker.service
==== AUTHENTICATING FOR org.freedesktop.systemd1.manage-units ===
Authentication is required to manage system services or units.
Authenticating as: root
Password:
==== AUTHENTICATION COMPLETE ===
[hongdada@localhost home]$ systemctl status docker.service
● docker.service - Docker Application Container EngineLoaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)Active: active (running) since 五 2018-04-20 08:11:34 CST; 12s agoDocs: http://docs.docker.comMain PID: 51878 (dockerd-current)CGroup: /system.slice/docker.service├─51878 /usr/bin/dockerd-current --add-runtime docker-runc=/usr/libexec/docker/docker-runc-cu...└─51883 /usr/bin/docker-containerd-current -l unix:///var/run/docker/libcontainerd/docker-con...