support py3 complie docker env

doc/COMPILE.md

@@ -11,7 +11,12 @@
 - cmake：3.2.2 and later
 - python：2.7.2 and later
 
-It is recommended to use Docker to prepare the compilation environment for the Paddle service: [CPU Dockerfile.devel](../tools/Dockerfile.devel), [GPU Dockerfile.gpu.devel](../tools/Dockerfile.gpu.devel)
+It is recommended to use Docker for compilation. We have prepared the Paddle Serving compilation environment for you: 
+
+- CPU: `hub.baidubce.com/paddlepaddle/serving:0.2.0-devel`，dockerfile: [Dockerfile.devel](../tools/Dockerfile.devel)
+- GPU: `hub.baidubce.com/paddlepaddle/serving:0.2.0-gpu-devel`，dockerfile: [Dockerfile.gpu.devel](../tools/Dockerfile.gpu.devel)
+
+This document will take Python2 as an example to show how to compile Paddle Serving. If you want to compile with Python 3, just adjust the python options of cmake.
 
 ## Get Code
 

doc/COMPILE_CN.md

@@ -11,7 +11,12 @@
 - cmake：3.2.2及以上
 - python：2.7.2及以上
 
-推荐使用Docker准备Paddle Serving编译环境：[CPU Dockerfile.devel](../tools/Dockerfile.devel)，[GPU Dockerfile.gpu.devel](../tools/Dockerfile.gpu.devel)
+推荐使用Docker编译，我们已经为您准备好了Paddle Serving编译环境：
+
+- CPU: `hub.baidubce.com/paddlepaddle/serving:0.2.0-devel`，dockerfile: [Dockerfile.devel](../tools/Dockerfile.devel)
+- GPU: `hub.baidubce.com/paddlepaddle/serving:0.2.0-gpu-devel`，dockerfile: [Dockerfile.gpu.devel](../tools/Dockerfile.gpu.devel)
+
+本文档将以Python2为例介绍如何编译Paddle Serving。如果您想用Python3进行编译，只需要调整cmake的Python相关选项即可。
 
 ## 获取代码
 

tools/Dockerfile.devel

@@ -18,5 +18,7 @@ RUN yum -y install wget >/dev/null \
     && python get-pip.py >/dev/null \
     && pip install google protobuf setuptools wheel flask >/dev/null \
     && rm get-pip.py \
+    && yum install -y python3 python3-devel \
+    && pip3 install google protobuf setuptools wheel flask \
     && yum -y install epel-release && yum -y install patchelf \
     && yum clean all

tools/Dockerfile.gpu.devel

@@ -19,5 +19,7 @@ RUN yum -y install wget >/dev/null \
     && python get-pip.py >/dev/null \
     && pip install google protobuf setuptools wheel flask >/dev/null \
     && rm get-pip.py \
+    && yum install -y python3 python3-devel \
+    && pip3 install google protobuf setuptools wheel flask \
     && yum -y install epel-release && yum -y install patchelf \
     && yum clean all