<commit_before>Build instructions for Hadoop

----------------------------------------------------------------------------------
Requirements:

* Unix System
* JDK 1.7+
* Maven 3.0 or later
* Findbugs 1.3.9 (if running findbugs)
* ProtocolBuffer 2.5.0
* CMake 2.6 or newer (if compiling native code), must be 3.0 or newer on Mac
* Zlib devel (if compiling native code)
* openssl devel (if compiling native hadoop-pipes and to get the best HDFS encryption performance)
* Jansson C XML parsing library (if compiling libwebhdfs)
* Linux FUSE (Filesystem in Userspace) version 2.6 or above (if compiling fuse_dfs)
* Internet connection for first build (to fetch all Maven and Hadoop dependencies)

----------------------------------------------------------------------------------
The easiest way to get an environment with all the appropriate tools is by means
of the provided Docker config.
This requires a recent version of docker (1.4.1 and higher are known to work).

On Linux:
    Install Docker and run this command:

    $ ./start-build-env.sh

On Mac:
    First make sure Virtualbox and docker toolbox are installed.
    You can use docker toolbox as described in http://docs.docker.com/mac/step_one/.
    $ docker-machine create --driver virtualbox \
                            --virtualbox-memory "4096" hadoopdev
    $ eval $(docker-machine env hadoopdev)
    $ ./start-build-env.sh

The prompt which is then presented is located at a mounted version of the source tree
and all required tools for testing and building have been installed and configured.

Note that from within this docker environment you ONLY have access to the Hadoop source
tree from where you started. So if you need to run<commit_msg>Supplement to HDFS-9047. (cherry picked from commit c722b62908984f8fb6ab2e0bfd40c090e8c830c7)<commit_after>Build instructions for Hadoop

----------------------------------------------------------------------------------
Requirements:

* Unix System
* JDK 1.7+
* Maven 3.0 or later
* Findbugs 1.3.9 (if running findbugs)
* ProtocolBuffer 2.5.0
* CMake 2.6 or newer (if compiling native code), must be 3.0 or newer on Mac
* Zlib devel (if compiling native code)
* openssl devel (if compiling native hadoop-pipes and to get the best HDFS encryption performance)
* Linux FUSE (Filesystem in Userspace) version 2.6 or above (if compiling fuse_dfs)
* Internet connection for first build (to fetch all Maven and Hadoop dependencies)

----------------------------------------------------------------------------------
The easiest way to get an environment with all the appropriate tools is by means
of the provided Docker config.
This requires a recent version of docker (1.4.1 and higher are known to work).

On Linux:
    Install Docker and run this command:

    $ ./start-build-env.sh

On Mac:
    First make sure Virtualbox and docker toolbox are installed.
    You can use docker toolbox as described in http://docs.docker.com/mac/step_one/.
    $ docker-machine create --driver virtualbox \
                            --virtualbox-memory "4096" hadoopdev
    $ eval $(docker-machine env hadoopdev)
    $ ./start-build-env.sh

The prompt which is then presented is located at a mounted version of the source tree
and all required tools for testing and building have been installed and configured.

Note that from within this docker environment you ONLY have access to the Hadoop source
tree from where you started. So if you need to run
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