docker 安装 Failed to restart docker.service: Unit not found 镜像加速

解决方案###

• 以前的安装残留 重新安装

• find / -name "docker*"

• centos8

• 添加软件源信息

• yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
• curl https://download.docker.com/linux/centos/docker-ce.repo -o /etc/yum.repos.d/docker-ce.repo

• 选择安装版本 yum list docker-ce.x86_64 --showduplicates | sort -r
• 发生错误 安装container.io 依赖 yum -y install https://download.docker.com/linux/fedora/30/x86_64/stable/Packages/containerd.io-1.2.6-3.3.fc30.x86_64.rpm
• 继续安装 yum install docker-ce

安装docker的加速镜像###

sudo mkdir -p /etc/docker  
sudo tee /etc/docker/daemon.json <<-'EOF'    
{    
  "registry-mirrors": ["https://阿里云",
			"http://registry.docker-cn.com",
   			 "http://docker.mirrors.ustc.edu.cn",
   			 "http://hub-mirror.c.163.com"]    
}    
EOF   
sudo systemctl daemon-reload    
sudo systemctl restart docker

centos8 /etc/docker/ 下如果没有daemon.json文件 touch一个