介绍Google的TensorFlow机器学习开源库，在UbuntuKylin上的安装和和源码编译。
原始官方文档参见：http://www.tensorflow.org.
TensorFlow学习资源推荐
tensorflow中文入门教程-含视频
tensorflow入门视频教程-含互动
本文是在安装caffe之后，继续安装TensorFlow，下面有些CUDA和 CUDNN的安装可见 Caffe + Ubuntu 15.04 + CUDA 7.5 在服务器上安装配置及卸载重新安装（已测试可执行）
安装TensorFlow的Requirements
Python 2.7 and Python 3.3+ Cuda toolkit >= 7.0 cuDNN >= v3 gcc > 4.8 g++ > 4.8 Bazel > 0.4.2
一、安装依赖包
1. 安装Tensorflow python API
sudo apt-get install python-pip python-dev
sudo apt-get install python-numpy swig python-dev
sudo apt-get install Git
2. 安装 Bazel
TensorFlow Serving requires Bazel 0.4.2 or higher，Bazel的安装可见官网。
OpenJDK做为GPL许可（GPL-licensed）的Java平台的开源化实现，Sun正式发布它已经六年有余。从发布那一时刻起，Java社区的大众们就又开始努力学习，以适应这个新的开源代码基础（code-base）。 [1]
OpenJDK在2013年发展迅速，被著名IT杂志SD Times评选为2013 SD Times 100，位于“极大影响力”分类第9位。
http://www.infoq.com/cn/news/2015/03/google-open-source-bazel
Google日前开源了他们内部使用的构建工具Bazel。
Bazel是一个类似于Make的工具，是Google为其内部软件开发的特点量身定制的工具，如今Google使用它来构建内部大多数的软件。它的功能有诸多亮点：
多语言支持：目前Bazel默认支持Java、Objective-C和C++，但可以被扩展到其他任何变成语言。
高级构建描述语言：项目是使用一种叫BUILD的语言来描述的，它是一种简洁的文本语言，它把一个项目视为一个集合，这个集合由一些互相关联的库、二进制文件和测试用例组成。相反，像Make这样的工具，需要去描述每个文件如何调用编译器。
多平台支持：同一套工具和相同的BUILD文件可以用来为不同的体系结构构建软件，甚至是不同的平台。在Google，Bazel被同时用在数据中心系统中的服务器应用和手机端的移动应用上。
可重复性：在BUILD文件中，每个库、测试用例和二进制文件都需要明确指定它们的依赖关系。当一个源码文件被修改时，Bazel凭这些依赖来判断哪些部分需要重新构建，以及哪些任务可以并行进行。这意味着所有构建都是增量的，并且相同构建总是产生一样的结果。
可伸缩性：Bazel可以处理大型项目；在Google，一个服务器软件有十万行代码是很常见的，在什么都不改的前提下重新构建这样一个项目，大概只需要200毫秒。
JDK8的安装（必须的）
sudo apt-get install openjdk-8-jdk openjdk-8-source
sudo apt-get install pkg-config zip g++ zlib1g-dev unzip
sudo add-apt-repository ppa:webupd8team/java #添加仓库
sudo apt-get update #更新软件列表
sudo apt-get install oracle-java8-installer #正式安装jdk8
java -version # 验证安装
2.1 安装 Bazel-方法1
echo “deb http://storage.googleapis.com/bazel-apt stable jdk1.8” | sudo tee /etc/apt/sources.list.d/bazel.list
curl https://storage.googleapis.com/bazel-apt/doc/apt-key.pub.gpg | sudo apt-key add -
sudo apt-get update
sudo apt-get install bazel
sudo apt-get upgrade bazel
bazel version
2.2 安装 Bazel-方法2
cd ~/Downloads
chmod +x bazel-0.4.5-installer-linux-x86_64.sh #对.sh文件授权
./bazel-0.4.5-installer-linux-x86_64.sh --user #运行.sh文件
bazel version
设置环境变量
export PATH="$PATH:$HOME/bin"
可能出现的问题
W: 无法下载 http://storage.googleapis.com/bazel-apt/dists/stable/InRelease Unable to find expected entry ‘jdk1.8/binary-i386/Packages’ in Release file (Wrong sources.list entry or malformed file)
E: Some index files Failed to download. They have been ignored,or old ones used instead.
的错误
sudo gedit /etc/apt/sources.list.d/bazel.list
将deb http://storage.googleapis.com/bazel-apt stable jdk1.8修改为deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8
3. CUDA和 CUDNN的安装，在 Linux 上开启 GPU 支持
为了编译并运行能够使用 GPU 的 TensorFlow,需要先安装 NVIDIA 提供的 Cuda Toolkit 7.5 和 CUDNN 7.5 V5
TensorFlow 的 GPU 特性只支持 NVidia Compute Capability >= 3.5 的显卡. 被支持的显卡 包括但不限于
NVidia Titan NVidia Titan X NVidia K20 NVidia K40
可见 Caffe + Ubuntu 15.04 + CUDA 7.5 在服务器上安装配置及卸载重新安装（已测试可执行）
二、Ubuntu/Linux直接安装
# 仅使用 cpu 的版本
$ pip install https://storage.googleapis.com/tensorflow/linux/cpu/tensorflow-1.0.1-cp27-none-linux_x86_64.whl
# 开启 GPU 支持的版本 (安装该版本的前提是已经安装了 CUDA sdk)
$ pip install https://storage.googleapis.com/tensorflow/linux/gpu/tensorflow-1.0.1-cp27-none-linux_x86_64.whl
三、源码编译
3.1 克隆 TensorFlow 仓库
git clone --recurse-submodules https://github.com/tensorflow/tensorflow #拉取源代码
–recurse-submodules 参数是必须得,用于获取 TesorFlow 依赖的 protobuf 库
3.2 配置 TensorFlow 的 Cuba 选项
cd tensorflow
./configure # 配置tensorflow
执行configure的时候会问你问题
Please specify the location of python. [Default is /usr/bin/python]
Please specify optimization flags to use during compilation [Default is -march=native]
Do you wish to use jemalloc as the malloc implementation? [Y/N]
y
Do you wish to build TensorFlow with Google Cloud Platform support? [Y/N]
y
Do you wish to build TensorFlow with Hadoop File System support? [Y/N]
y
Do you wish to build TensorFlow with the XLA just-in-time compiler (experimental)? [Y/N]
y
Do you wish to build TensorFlow with OpenCL support? [Y/N]
n
Do you wish to build TensorFlow with CUDA support? [Y/N]
y
若 Do you wish to build TensorFlow with OpenCL support? [Y/N] 中选择 y，则需要安装 OpenCL drivers 和 ComputeCpp compiler，具体步骤可参考
Optional: Install OpenCL (Experimental,Linux only)
否则，会出现如下一直循环的情况。
3.3 编译
mkdir /tmp/tensorflow_pkg
cd tensorflow
bazel build -c opt //tensorflow/tools/pip_package:build_pip_package
出现的问题
The 'build' command is only supported from within a workspace
cd tensorflow
3.3.2 有 GPU 支持
cd tensorflow
bazel build -c opt @H_533_502@--config@H_533_502@=cuda //tensorflow/tools/pip_package:build_pip_package
3.3.3 生成 pip安装包
bazel-bin/tensorflow/tools/pip_package/build_pip_package /tmp/tensorflow_pkg
cd 到 /tmp/tensorflow_pkg目录下，找到编译好的whl文件
cd /tmp/tensorflow_pkg
sudo pip install @H_533_502@--config@H_533_502@=cuda tensorflow@H_533_502@-1.0.1-cp27-none-linux_x86_64.whl
3.3.4 编译目标程序,开启 GPU 支持
bazel build -c opt @H_533_502@--config@H_533_502@=cuda //tensorflow/cc:tutorials_example_trainer
bazel-bin/tensorflow/cc/tutorials_example_trainer @H_533_502@--use_gpu
四、设置TensorFlow环境
cd tensorflow
bazel build -c opt //tensorflow/tools/pip_package:build_pip_package
# To build with GPU support:
bazel build -c opt --config=cuda //tensorflow/tools/pip_package:build_pip_package
mkdir _python_build
cd _python_build
ln -s ../bazel-bin/tensorflow/tools/pip_package/build_pip_package.runfiles/org_tensorflow/* .
ln -s ../tensorflow/tools/pip_package/* .
sudo python setup.py develop
五、测试TensorFlow
import tensorflow as tf
hello = tf.constant('Hello,TensorFlow!')
sess = tf.Session()
print sess.run(hello)
Hello,TensorFlow!
a = tf.constant(10)
b = tf.constant(32)
print sess.run(a+b)
42
六、出现的问题
gcc 版本 -fno-canonical-system-headers
当执行
./configure
出现如下问题
INFO: Found 1 target...
Slow read: a 51765952-byte read from /home/bids/.cache/bazel/_bazel_bids/5df0e0fb624204ab1c5ce0472e695b94/external/local_config_cuda/cuda/lib/libcurand.so.7.5 took 9675ms.
INFO: From Compiling external/llvm/lib/Support/Host.cpp:
external/llvm/lib/Support/Host.cpp: In function 'llvm::StringRef llvm::sys::getHostcpuName()':
external/llvm/lib/Support/Host.cpp:898:5: warning: 'Type' may be used uninitialized in this function [-Wuninitialized]
external/llvm/lib/Support/Host.cpp:964:7: warning: 'Subtype' may be used uninitialized in this function [-Wmaybe-uninitialized]
ERROR: /home/bids/.cache/bazel/_bazel_bids/5df0e0fb624204ab1c5ce0472e695b94/external/llvm/BUILD:1667:1: C++ compilation of rule '@llvm//:support' Failed: gcc Failed: error executing command /usr/bin/gcc -U_FORTIFY_SOURCE -fstack-protector -Wall -B/usr/bin -B/usr/bin -Wunused-but-set-parameter -Wno-free-nonheap-object -fno-omit-frame-pointer -g0 -O2 '-D_FORTIFY_SOURCE=1' -DNDEBUG ... (remaining 43 argument(s) skipped): com.google.devtools.build.lib.shell.BadExitStatusException: Process exited with status 1.
In file included from external/llvm/lib/Support/DynamicLibrary.cpp:16:0:
external/llvm/include/llvm/ADT/DenseSet.h:226:16: error: 'using llvm::DenseSet<ValueT,ValueInfoT>::BaseT::BaseT' conflicts with a prevIoUs declaration
external/llvm/include/llvm/ADT/DenseSet.h:223:39: note: prevIoUs declaration 'using BaseT = class llvm::detail::DenseSetImpl<ValueT,llvm::DenseMap<ValueT,llvm::detail::DenseSetEmpty,ValueInfoT,llvm::detail::DenseSetPair<ValueT> >,ValueInfoT>'
external/llvm/include/llvm/ADT/DenseSet.h:244:16: error: 'using llvm::SmallDenseSet<ValueT,InlineBuckets,ValueInfoT>::BaseT::BaseT' conflicts with a prevIoUs declaration
external/llvm/include/llvm/ADT/DenseSet.h:241:18: note: prevIoUs declaration 'using BaseT = class llvm::detail::DenseSetImpl<ValueT,llvm::SmallDenseMap<ValueT,ValueInfoT>'
Target //tensorflow/tools/pip_package:build_pip_package Failed to build
Use --verbose_failures to see the command lines of Failed build steps.
INFO: Elapsed time: 54.671s,Critical Path: 28.01s
bids@bids-HP-Z840-Workstation:~/tensorflow$ bazel build -c opt --config=cuda //tensorflow/tools/pip_package:build_pip_package
WARNING: /home/bids/tensorflow/tensorflow/contrib/learn/BUILD:15:1: in py_library rule //tensorflow/contrib/learn:learn: target '//tensorflow/contrib/learn:learn' depends on deprecated target '//tensorflow/contrib/session_bundle:exporter': Use SavedModel Builder instead.
WARNING: /home/bids/tensorflow/tensorflow/contrib/learn/BUILD:15:1: in py_library rule //tensorflow/contrib/learn:learn: target '//tensorflow/contrib/learn:learn' depends on deprecated target '//tensorflow/contrib/session_bundle:gc': Use SavedModel instead.
INFO: Found 1 target...
ERROR: /home/bids/.cache/bazel/_bazel_bids/5df0e0fb624204ab1c5ce0472e695b94/external/zlib_archive/BUILD.bazel:5:1: C++ compilation of rule '@zlib_archive//:zlib' Failed: crosstool_wrapper_driver_is_not_gcc Failed: error executing command external/local_config_cuda/crosstool/clang/bin/crosstool_wrapper_driver_is_not_gcc -U_FORTIFY_SOURCE '-D_FORTIFY_SOURCE=1' -fstack-protector -fPIE -Wall -Wunused-but-set-parameter ... (remaining 37 argument(s) skipped): com.google.devtools.build.lib.shell.BadExitStatusException: Process exited with status 1.
gcc: error: unrecognized command line option '-fno-canonical-system-headers'
Target //tensorflow/tools/pip_package:build_pip_package Failed to build
Use --verbose_failures to see the command lines of Failed build steps.
INFO: Elapsed time: 4.726s,Critical Path: 1.88s
解决方法：
这是因为gcc 版本的问题。因之前安装caffe 所需的gcc版本为4.7，故升级到4.9版本即可。可参考
Porting to GCC 4.7
Caffe + Ubuntu 15.04 + CUDA 7.5 在服务器上安装配置及卸载重新安装（已测试可执行）
cd /usr/bin
sudo rm gcc
sudo ln -s gcc-4.9 gcc
sudo rm g++
sudo ln -s g++-4.9 g++
问题 Oracle JDK 8 is not installed
当执行如下
sudo apt-get install openjdk@H_533_502@-8-jdk openjdk@H_533_502@-8-source
出现如下错误
download Failed
Oracle JDK 8 is NOT installed.
dpkg: error processing package oracle-java8-installer (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
oracle-java8-installer
E: Sub-process /usr/bin/dpkg returned an error code (1)
解决方法： 这是因为oracle-java8-installer 不能下载或者下载不完整导致的。
cp -r jdk@H_533_502@-8u121-linux-x64.tar.gz /var/cache/oracle-jdk8-installer@H_533_502@/
sudo apt-get install oracle-jdk8-installer
问题 TensorFlow ImportError: cannot import name pywrap_tensorflow
当执行如下
cd tensorflow
import tensorflow as tf
出现如下错误
Traceback (most recent call last): File "<stdin>",line 1,in <module> File "tensorflow/__init__.py",line 23,in <module> from tensorflow.Python import * File "tensorflow/python/__init__.py",line 48,in <module> from tensorflow.python import pywrap_tensorflow ImportError: cannot import name pywrap_tensorflow
解决方法： 这是因为python误以为tensorflow目录中的tensorflow就是要导入的模块
不要在tensorflow中运行python或者ipython
参考文献：
