Linux中修改docker镜像源及安装docker

1、首先备份系统自带yum源配置文件/etc/yum.repos.d/CentOS-Base.repo

 mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak

2、进入yum源配置文件所在的文件夹

cd /etc/yum.repos.d/

3、下载163的yum源配置文件(CentOS7)

wget http://mirrors.163.com/.help/CentOS7-Base-163.repo

清华大学镜像源地址：https://mirrors.tuna.tsinghua.edu.cn/

4、清理缓存

yum clean all

5、测试下载安装

yum install gcc

6、安装docker

yum install docker

7、启动

systemctl start docker

8、启动报错

[root@localhost yum.repos.d]# 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 yum.repos.d]# systemctl status docker
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Wed -- :: UTC; 28s 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 --init-path=/usr/libexec/docker/docker-init-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)

Dec  :: localhost.localdomain systemd[]: Starting Docker Application Container Engine...
Dec  :: localhost.localdomain dockerd-current[]: time="2018-12-12T07:27:22.024162402Z" level=warning msg="could not change group /var/run/docker...t found"
Dec  :: localhost.localdomain dockerd-current[]: time="2018-12-12T07:27:22.038636556Z" level=info msg="libcontainerd: new containerd process, pid: 4170"
Dec  :: localhost.localdomain dockerd-current[]: Error starting daemon: SELinux is not supported with the overlay2 graph driver on this kernel. ...d=false)
Dec  :: localhost.localdomain systemd[]: docker.service: main process exited, code=exited, status=/FAILURE
Dec  :: localhost.localdomain systemd[]: Failed to start Docker Application Container Engine.
Dec  :: localhost.localdomain systemd[]: Unit docker.service entered failed state.
Dec  :: localhost.localdomain systemd[]: docker.service failed.
Hint: Some lines were ellipsized, use -l to show in full.

根据提示查看一下详情，执行：journalctl -xe

Dec  :: localhost.localdomain dockerd[]: time="2018-12-13T06:42:24.350020859Z" level=info msg="libcontainerd: new containerd process, pid: 2722"
Dec  :: localhost.localdomain dockerd[]: time="2018-12-13T06:42:25.356303658Z" level=error msg="[graphdriver] prior storage driver overlay2 failed: driver
Dec  :: localhost.localdomain dockerd[]: Error starting daemon: error initializing graphdriver: driver not supported

错误原因：error initializing graphdriver: driver not supported
解决办法：在 /etc/docker 目录下创建daemon.json文件，并且加入以下配置

touch daemon.json
vi daemon.json
{
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ]
}

再次启动

systemctl start docker

问题解决

9、又来一个问题

Error starting daemon: SELinux is not supported with the overlay2 graph driver on this kernel. Either boot

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

vi /etc/sysconfig/docker

#设置
--selinux-enabled=false