在CentOS/RHEL中安装Docker

# (安装 Docker CE)
## 设置仓库
### 安装所需包
sudo yum install -y yum-utils device-mapper-persistent-data lvm2

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

## 安装 Docker CE
sudo yum update -y && sudo yum install -y \
  containerd.io-1.2.13 \
  docker-ce-19.03.11 \
  docker-ce-cli-19.03.11

## 创建 /etc/docker 目录
sudo mkdir /etc/docker

# 设置 Docker daemon
cat <<EOF | sudo tee /etc/docker/daemon.json
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ]
}
EOF

# 重启 Docker
sudo systemctl daemon-reload
sudo systemctl restart docker