CentOS7.2 安装Docker

Docker 要求 CentOS 系统的内核版本高于 3.10 ，查看本页面的前提条件来验证你的CentOS 版本是否支持 Docker 。

通过 uname -r 命令查看你当前的内核版本

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

Docker 软件包和依赖包已经包含在默认的 CentOS-Extras 软件源里，安装命令如下:

yum -y install docker

启动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.

查看具体错误信息：

[root@localhost /]# systemctl status docker.service
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since 五 -- :: CST; 3min 57s ago
     Docs: http://docs.docker.com
  Process:  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=/FAILURE)
 Main PID:  (code=exited, status=/FAILURE)

4月  :: localhost.localdomain systemd[]: Starting Docker Application Container Engine...
4月  :: localhost.localdomain dockerd-current[]: time="2018-04-20T06:50:50.921964698+08:00" level=warning msg="could not ...ound"
4月  :: localhost.localdomain dockerd-current[]: time="2018-04-20T06:50:50.927241794+08:00" level=info msg="libcontainerd...4010"
4月  :: localhost.localdomain dockerd-current[]: time="2018-04-20T06:50:51.936045098+08:00" level=warning msg="overlay2: the b...
4月  :: localhost.localdomain dockerd-current[]: Error starting daemon: SELinux is not supported with the overlay2 graph ...alse)
4月  :: localhost.localdomain systemd[]: docker.service: main process exited, code=exited, status=/FAILURE
4月  :: localhost.localdomain systemd[]: Failed to start Docker Application Container Engine.
4月  :: localhost.localdomain systemd[]: Unit docker.service entered failed state.
4月  :: localhost.localdomain systemd[]: docker.service failed.
Hint: Some lines were ellipsized, use -l to show in full.

可以看出错误信息

Error starting daemon: SELinux is not supported with the overlay2 graph ...alse)
此linux的内核中的SELinux不支持 overlay2 graph driver ，解决方法有两个，要么启动一个新内核，要么就在docker里禁用selinux，--selinux-enabled=false

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

修改配置：

# 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}" ]; then
    DOCKER_CERT_PATH=/etc/docker
fi

# Do not add registries in this file anymore. Use /etc/containers/registries.conf
# from the atomic-registries package.
#

在--selinux-enabled后面添加=false即可！

重新启动docker

[root@localhost /]# service docker start
Redirecting to /bin/systemctl start docker.service
[root@localhost /]# docker info
Containers:
 Running:
 Paused:
 Stopped:
Images:
Server Version: 1.13.
Storage Driver: overlay2
 Backing Filesystem: xfs
 Supports d_type: false
 Native Overlay Diff: false
Logging Driver: journald
Cgroup Driver: systemd
Plugins:
 Volume: local
 Network: 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:
 seccomp
  WARNING: You're not using the default seccomp profile
  Profile: /etc/docker/seccomp.json
Kernel Version: 3.10.-.el7.x86_64
Operating System: CentOS Linux  (Core)
OSType: linux
Architecture: x86_64
Number of Docker Hooks:
CPUs:
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/
Live Restore Enabled: false
Registries: docker.io (secure)

测试运行hello-world

[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:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 . The Docker client contacted the Docker daemon.
 . The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 . The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 . The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share 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/

启动重启命令：

[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 Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
   Active: active (running) since 五 -- :: CST; 12s ago
     Docs: http://docs.docker.com
 Main PID:  (dockerd-current)
   CGroup: /system.slice/docker.service
           ├─ /usr/bin/dockerd-current --add-runtime docker-runc=/usr/libexec/docker/docker-runc-cu...
           └─ /usr/bin/docker-containerd-current -l unix:///var/run/docker/libcontainerd/docker-con...

http://www.runoob.com/docker/centos-docker-install.html

https://www.cnblogs.com/amoyzhu/p/5261393.html

https://blog.csdn.net/11b202/article/details/21389067

http://www.21yunwei.com/archives/4437