Ubuntu18.04通过.deb包安装Docker

通过参照官方文档和一点小摸索出来的，记录一下。

1. 下载包，总共需要下载三个,可以在https://download.docker.com/linux/ubuntu/dists/bionic/pool/stable/amd64/上选择最新版：
   1. https://download.docker.com/linux/ubuntu/dists/bionic/pool/stable/amd64/containerd.io_1.2.0-1_amd64.deb
   2. https://download.docker.com/linux/ubuntu/dists/bionic/pool/stable/amd64/docker-ce-cli_18.09.0~3-0~ubuntu-bionic_amd64.deb
   3. https://download.docker.com/linux/ubuntu/dists/bionic/pool/stable/amd64/docker-ce_18.09.0~3-0~ubuntu-bionic_amd64.deb
2. 将三个包放到Linux的某个文件夹下，此处用的是命令的方式，注意将“[email protected]:/home/sysadm/”换成自己的：
   1. scp containerd.io_1.2.0-1_amd64.deb [email protected]:/home/sysadm/
   2. scp docker-ce-cli_18.09.0~3-0~ubuntu-bionic_amd64.deb [email protected]:/home/sysadm/
   3. scp docker-ce_18.09.0~3-0~ubuntu-bionic_amd64.deb [email protected]:/home/sysadm/
3. 安装libltdl7：
   1. sudo apt-get install libltdl7
4. 按顺序安装三个包，注意顺序不能错：
   1. sudo dpkg -i docker-ce-cli_18.09.0~3-0~ubuntu-bionic_amd64.deb
   2. sudo dpkg -i containerd.io_1.2.0-1_amd64.deb
   3. sudo dpkg -i docker-ce_18.09.0~3-0~ubuntu-bionic_amd64.deb
5. docker --version