删除原有的docker应用（如果有的话）：
sudo apt-get remove docker docker-engine docker.io
更新一下：
sudo apt-get update
下载支持 https 的相关依赖：
sudo apt-get install
apt-transport-https
ca-certificates
curl
software-properties-common
下载docker的官方gpg密钥：
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
添加apt仓库：
sudo add-apt-repository
"deb [arch=amd64] https://download.docker.com/linux/ubuntu
$(lsb_release -cs)
stable"
再更新一下：
sudo apt-get update
下载docker ce版本：
sudo apt-get install docker-ce
为了认证docker安装好了，要记得跑一下hello world程序哦：
sudo docker run hello-world
提示如下信息，说明安装docker成功了：
zifeiy@zifeiy-S1:~$ sudo docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
9db2ca6ccae0: Pull complete
Digest: sha256:4b8ff392a12ed9ea17784bd3c9a8b1fa3299cac44aca35a85c90c5e3c7afacdc
Status: Downloaded newer image for hello-world:latest
Hello from Docker!
This message shows that your installation appears to be working correctly.
To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
(amd64)
3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.
To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash
Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/engine/userguide/
参考链接：Docker官方文档