前提说明

查看自己的内核

uname -r
cat /etc/redhat-release

docker的基本组成

docker的架构图

docker三要素

这有三个容器，均来自与同一个模板，Person

CentOS6安装Docker

yum install -y epel-release

Docker使用EPEL发布，RHEL系的OS首先要确保已经持有EPEL仓库，否则先检查OS的版本，然后安装相应的EPEL包。

yum install docker-io

查看docker配置文件


docker的启动

service docker start

查看docker版本信息

docker version

CentOS7安装Docker

卸载老版本的Docker

yum remove docker \

                  docker-client \

                  docker-client-latest \

                  docker-common \

                  docker-latest \

                  docker-latest-logrotate \

                  docker-logrotate \

                  docker-selinux \

                  docker-engine-selinux \

                  docker-engine

安装需要的软件包

yum install -y yum-utils device-mapper-persistent-data lvm2

设置stable镜像仓库

yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

更新yun软件包索引

yum makecache fast

安装DOCKER CE

yum -y install docker-ce

启动Docker

systemctl start docker

测试，查看版本，运行仓库

docker version
docker run hello-word

配置镜像加速

mkdir -p /etc/docker
vim /etc/docker/daemon.json
#网易云
{"registry-mirrors": ["http://hub-mirror.c.163.com"] }
 #阿里云
{
  "registry-mirrors": ["https://｛自已的编码｝.mirror.aliyuncs.com"]
}
systemctl daemon-reload
systemctl restart docker

CentOS8安装Docker

安装社区版Docker Engine

yum install -y yum-utils \
  device-mapper-persistent-data \
  lvm2

sudo yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo

yum-config-manager --enable docker-ce-nightlyyum-config-manager --enable docker-ce-test

yum-config-manager --enable docker-ce-test

yum-config-manager --disable docker-ce-nightly

安装这一步报错

yum install docker-ce docker-ce-cli containerd.io

报错内容

[root@localhost yum.repos.d]# yum install docker-ce docker-ce-cli containerd.io
Last metadata expiration check: 0:04:46 ago on Mon 16 Mar 2020 03:40:11 PM CST.
Package containerd.io-1.2.0-3.el7.x86_64 is already installed.
Error:
 Problem: package docker-ce-3:19.03.8-3.el7.x86_64 requires containerd.io >= 1.2.2-3, but none of the providers can be installed
  - cannot install the best candidate for the job
  - package containerd.io-1.2.10-3.2.el7.x86_64 is excluded
  - package containerd.io-1.2.13-3.1.el7.x86_64 is excluded
  - package containerd.io-1.2.2-3.3.el7.x86_64 is excluded
  - package containerd.io-1.2.2-3.el7.x86_64 is excluded
  - package containerd.io-1.2.4-3.1.el7.x86_64 is excluded
  - package containerd.io-1.2.5-3.1.el7.x86_64 is excluded
  - package containerd.io-1.2.6-3.3.el7.x86_64 is excluded
  - package containerd.io-1.2.11-3.2.el7.x86_64 is excluded
  - package containerd.io-1.2.12-3.1.el7.x86_64 is excluded
  - package containerd.io-1.2.6-3.2.el7.x86_64 is excluded
(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)

分析原因
看上面的内容，说的是containerd.io >= 1.2.2-3 ，意思就是 containerd.io 的版本必须大于等于 1.2.2-3
解决
如果不想降低docker 版本，那么就更新 containerd.io 的版本

yum install -y wget

wget https://download.docker.com/linux/centos/7/x86_64/edge/Packages/containerd.io-1.2.6-3.3.el7.x86_64.rpm

yum install -y  containerd.io-1.2.6-3.3.el7.x86_64.rpm

 yum install docker-ce docker-ce-cli

一直‘y’

启动 docker

systemctl start docker

检查是否安装成功
检查版本号

docker -v

返回版本信息

参考文章：https://www.backendcloud.cn/2020/03/16/centos8installdocker/