Create install_Docker_en.md

doc/fluid/beginners_guide/install/install_Docker_en.md

+# **Installation with Docker**
+
+[Docker](https://docs.docker.com/install/) is an open-source application container engine, with which you can seperate the installation and use of PaddlePaddle from the system environment, and share GPU and network resources with the localhost.
+
+## Environment Preparations
+
+- For system types supporting now, please refer to [Installation Instructions](./index_en.html). Using Docker on CentOS 6 is not supported.
+
+- [Install Docker](https://hub.docker.com/search/?type=edition&offering=community) on the localhost.
+
+- If you need to start GPU supporting on Linux, please [install nvidia-docker](https://github.com/NVIDIA/nvidia-docker).
+
+## Installation Steps
+
+1. Pull PaddlePaddle image
+
+	* CPU version PaddlePaddle： `docker pull hub.baidubce.com/paddlepaddle/paddle:[版本号]`
+
+	* GPU version PaddlePaddle： `docker pull hub.baidubce.com/paddlepaddle/paddle:[版本号]-gpu-cuda9.0-cudnn7`
+
+    Please fill in the version number of PaddlePaddle such as 1.2 after `:`. For more details please refer to [Image Instructions](#dockers)
+
+2. Construct and enter Docker container
+
+	`docker run --name [Name of container] -it -v $PWD:/paddle <imagename> /bin/bash`
+
+	> Parameters in the commands above mean: --name [Name of container]  set the name ofDocker；-it  the parameter means the container has been working interactively with the localhost； -v $PWD:/paddle  appoints to pull the present path(which will unfold to absolute path by PWD variable on Linux) to /paddle catalogue inside the container； `<imagename>` appoints the name of the image needed, and you can check by `docker images` command；/bin/bash  is the command to execute in Docker
+
+Until now, you have installed PaddlePaddle with Docker successfully, for more usage details please refer to [Docker Official Documents](https://docs.docker.com)
+
+<a name="dockers"></a>
+</br></br>
+### **Image Instructions**
+<p align="center">
+<table>
+	<thead>
+	<tr>
+		<th> version name </th>
+		<th> version instructions </th>
+	</tr>
+	</thead>
+	<tbody>
+	<tr>
+		<td> hub.baidubce.com/paddlepaddle/paddle:latest </td>
+		<td> newest image having installed CPU version PaddlePaddle </td>
+	</tr>
+		<tr>
+		<td> hub.baidubce.com/paddlepaddle/paddle:[Version] </td>
+		<td> old version image having installed PaddlePaddleversion </td>
+	</tr>
+	<tr>
+		<td> hub.baidubce.com/paddlepaddle/paddle:latest-gpu </td>
+		<td> newest image having installed GPU version PaddlePaddle </td>
+	</tr>
+		<tr>
+		<td> hub.baidubce.com/paddlepaddle/paddle:latest-dev </td>
+		<td> newest development environment of PaddlePaddle </td>
+	</tr>
+   </tbody>
+</table>
+</p>
+
+You can find docker images of all versions of PaddlePaddle in [DockerHub](https://hub.docker.com/r/paddlepaddle/paddle/tags/).
+
+### Anouncements
+
+* Python version is 2.7 in the image
+* PaddlePaddle Docker doesn't install `vim` by default in order to decrease the volume, and you can execute `apt-get install -y vim` command in the container for compling codes.
+
+### Supplementary Instructions
+
+* When you need to enter Docker container the second time, please use the following commands:
+```
+	#start the previously constructed container
+	docker start [Name of container]
+
+	#enter the started container
+	docker attach [Name of container]
+```
+* If you are new with Docker, please refer ro information on the Internet, such as [Docker Tutorial](http://www.runoob.com/docker/docker-hello-world.html)
+
+## How to Unload
+
+After entering Docker, execute the following commands:
+
+* ***CPU version PaddlePaddle***: `pip uninstall paddlepaddle`
+
+* ***GPU version PaddlePaddle***: `pip uninstall paddlepaddle-gpu`
+
+or use `docker rm [Name of container]` to delete Docker container directly.
+