Add docker compilation images

# Install Milvus from Source Code

## Software requirements

- [Build from source](https://github.com/jielinxu/milvus/edit/0.6.0/install.md#build-from-source)

- [Compile Milvus on Docker](https://github.com/jielinxu/milvus/edit/0.6.0/install.md#compile-milvus-on-docker)

## Build from source

### Requirements

- Ubuntu 18.04 or higher

- CMake 3.12 or higher

##### For GPU version, you will also need:

##### For GPU-enabled version, you will also need:

- CUDA 10.0 or higher

- NVIDIA driver 418 or higher

## Compilation

### Compilation

### Step 1 Install dependencies

#### Step 1 Install dependencies

```shell

$ cd [Milvus root path]/core

$ ./ubuntu_build_deps.sh

```

### Step 2 Build

#### Step 2 Build

```shell

$ cd [Milvus root path]/core

$ ./build.sh -t Release

```

By default, it will build CPU version. To build GPU version, add `-g` option

By default, it will build CPU-only version. To build GPU version, add `-g` option

```shell

$ ./build.sh -g

```

When the build is completed, all the stuff that you need in order to run Milvus will be installed under `[Milvus root path]/core/milvus`.

## Launch Milvus server

### Launch Milvus server

```shell

$ cd [Milvus root path]/core/milvus

$ ./stop_server.sh

```

## Compile Milvus on Docker

With this dockerfile, you should be able to compile CPU-only or GPU-enabled Milvus on any Linux platform that run Docker. To build a GPU-enabled Milvus, you neeed to install [NVIDIA Docker](https://github.com/NVIDIA/nvidia-docker/) first.

### Step 1 Pull Milvus Docker images

Pull CPU-only image:

```shell

$ Docker pull milvusdb/milvus-cpu-build-env:v0.6.0-ubuntu18.04

```

Pull GPU-enabled image:

```shell

$ Docker pull milvusdb/milvus-gpu-build-env:v0.6.0-ubuntu18.04

```

### Step 2 Start the Docker container

Start a CPU-only container:

```shell

$ Docker run -it -p 19530:19530 -d milvusdb/milvus-cpu-build-env:v0.6.0-ubuntu18.04

```

Start a GPU container:

```shell

$ Docker run — runtime=nvidia -it -p 19530:19530 -d milvusdb/milvus-gpu-build-env:v0.6.0-ubuntu18.04

```

To enter the container:

```shell

$ Docker exec -it [container_id] bash

```

### Step 3 Download Milvus source code and compile it in the container

Download Milvus source code:

```shell

$ cd /home

$ wget https://github.com/milvus-io/milvus/archive/0.6.0.zip

```

Unzip the source package:

```shell

$ Apt-get update

$ Apt-get install unzip

$ unzip ./0.6.0.zip

```

The source code is extracted into a folder called `milvus-0.6.0`. 

If you are using a CPU-only image, compile it like this:

```shell

$ ./build.sh -t Release

```

For GPU-enabled image, you need to add a `-g` parameter:

```shell

$ ./build.sh -g -t Release

```

Then start Milvus server：

```shell

$ ./start_server.sh

```

## Troubleshooting

1. If you encounter the following error when compiling: 

`protocol https not supported or disabled in libcurl`.