Added docs for DiskImageBuilder.

Partially implements blueprint docs-for-v02

Change-Id: Icd0f6a357702a3a20a7aeb70d7ee5ca0f057197d

doc/source/userdoc/diskimagebuilder.rst

@@ -1,2 +1,83 @@
 Disk Image Builder
 ==================
+
+As of now vanilla plugin works with images with pre-installed Apache Hadoop. To
+simplify task of building such images we use
+`Disk Image Builder <https://github.com/stackforge/diskimage-builder>`_.
+
+`Disk Image Builder` is built of elements. An element is a particular set of
+code that alters how the image is built, or runs within the chroot to prepare
+the image.
+
+
+.. note::
+
+   Savanna requires images with cloud-init package installed:
+
+   * `For Fedora <http://pkgs.fedoraproject.org/cgit/cloud-init.git/>`_
+   * `For Ubuntu <http://packages.ubuntu.com/precise/cloud-init>`_
+
+In this document you will find instuction on how to build Ubuntu and Fedora
+images with Apache Hadoop 1.1.2.
+
+1. Clone the repository "https://github.com/stackforge/diskimage-builder" locally.
+
+   .. sourcecode:: concole
+
+       git clone https://github.com/stackforge/diskimage-builder
+
+2. Add ``~/diskimage-builder/bin/`` directory to your path. For example:
+
+   .. sourcecode:: bash
+
+       PATH=$PATH:/home/$USER/diskimage-builder/bin/.
+
+3. Export the following variable
+    ``ELEMENTS_PATH=/home/$USER/diskimage-builder/elements/``
+    to your ``.bashrc``. Then source it.
+
+4. Copy file ``img-build-sudoers`` from ``~/disk-image-builder/sudoers.d/``
+   to your ``/etc/sudoers.d/``:
+
+   .. sourcecode:: bash
+
+       sudo cp ~/disk-image-builder/sudoers.d/img-build-sudoers /etc/sudoers.d/
+       sudo chmod 440 /etc/sudoers.d/img-build-sudoers
+       sudo chown root:root /etc/sudoers.d/img-build-sudoers
+
+5. Move ``elements`` directory to ``disk-image-builder/elements/``
+
+   .. sourcecode:: console
+
+    mv elements/*  /path_to_disk_image_builder/diskimage-builder/elements/
+
+6. Call the following command to create cloud image with Apache Hadoop:
+
+   **Ubuntu cloud image**
+
+   .. sourcecode:: console
+
+       DIB_HADOOP_VERSION=1.1.2 JAVA_FILE=jdk-7u21-linux-x64.tar.gz \
+           disk-image-create base vm hadoop ubuntu root-passwd -o hadoop_1_1_2
+
+   **Fedora cloud image**
+
+   .. sourcecode:: console
+
+        DIB_HADOOP_VERSION=1.1.2 JAVA_FILE=jdk-7u21-linux-x64.tar.gz \
+         DIB_IMAGE_SIZE=10 disk-image-create base vm fedora hadoop_fedora \
+         root-passwd -o fedora_hadoop_1_1_2
+
+   In this command:
+
+   * ``DIB_HADOOP_VERSION`` - version of Hadoop to install (currently supports
+     only Apache Hadoop 1.1.2)
+   * ``JAVA_DOWNLOAD_URL`` - you also can use this parameter instead of
+     ``DIB_HADOOP_VERSION`` to specify download link for JDK (tarball or bin)
+   * ``DIB_IMAGE_SIZE`` - is parameter that specifes a volume of hard disk of
+     instance. You need to specify it because Fedora doesn't use all available
+     volume.
+
+   If you have already downloaded the JDK package, move it to
+   ``elements/hadoop/install.d/`` or ``elements/hadoop_fedora/post-install.d/``
+   and use its filename as ``JAVA_FILE`` parameter.