Add "Use a specific hyperkube image" doc

This commit adds a "Use a specific hyperkube image" page
to the docs. This shows how to use CUSTOM_YAML to set
hyperkube_image_repo and hyperkube_image_tag.

Change-Id: I14c63329685ae985d75c036ae879ed649d0d505f

doc/source/index.rst

@@ -20,6 +20,7 @@ Contents
    generate_inventory
    packer
    collect_info
+   specify_hyperkube_image
 
 Search in this guide
 ~~~~~~~~~~~~~~~~~~~~

doc/source/inventory_repo.rst

@@ -1,3 +1,5 @@
+.. _inventory-and-deployment-data-management:
+
 Inventory and deployment data management
 ========================================
 

doc/source/quickstart.rst

@@ -74,3 +74,8 @@ Run script:
 ::
 
     bash ~/deploy-k8s.sh
+
+.. note::
+
+   See :ref:`specify-hyperkube-image` if you want to specify the location
+   and version of the ``hyperkube`` image to use.

doc/source/specify_hyperkube_image.rst

@@ -0,0 +1,43 @@
+.. _specify-hyperkube-image:
+
+=================================
+Deploy a specific hyperkube image
+=================================
+
+By default ``fuel-ccp-installer`` uses an hyperkube image downloaded from the
+``quay.io`` images repository. See the variables ``hyperkube_image_repo`` and
+``hyperkube_image_tag`` variables in the `kargo_default_common.yaml`_ file.
+
+To use a specific version of ``hyperkube`` the ``hyperkube_image_repo`` and
+``hyperkube_image_tag`` variables can be set in the ``deploy-k8s.sh`` script.
+This is done through the ``CUSTOM_YAML`` environment variable. Here is an
+example:
+
+::
+
+    #!/bin/bash
+    set -ex
+
+    # CHANGE ADMIN_IP AND SLAVE_IPS TO MATCH YOUR ENVIRONMENT
+    export ADMIN_IP="10.90.0.2"
+    export SLAVE_IPS="10.90.0.2 10.90.0.3 10.90.0.4"
+    export DEPLOY_METHOD="kargo"
+    export WORKSPACE="${HOME}/workspace"
+    export CUSTOM_YAML='hyperkube_image_repo: "gcr.io/google_containers/hyperkube-amd64"
+    hyperkube_image_tag: "v1.3.7"
+    '
+
+    mkdir -p $WORKSPACE
+    cd ./fuel-ccp-installer
+    bash -x "./utils/jenkins/run_k8s_deploy_test.sh"
+
+In this example the ``CUSTOM_YAML`` variable includes the definitions of
+the ``hyperkube_image_repo`` and ``hyperkube_image_tag`` variables, defining
+what ``hyperkube`` image to use and what repository to get the image from.
+
+.. note::
+   If you use an inventory Git repo please refer
+   :ref:`inventory-and-deployment-data-management` to know how you can set
+   variables for the environment.
+
+.. _kargo_default_common.yaml: https://github.com/openstack/fuel-ccp-installer/blob/master/utils/kargo/kargo_default_common.yaml