Add Centos VM blueprint documentation

Change-Id: I215f1fbb757c9c8f4236e19d6f0ddcc15be306d3
Issue-Id: DCAEGEN2-193
Signed-off-by: Jack Lucas <jflucas@research.att.com>
diff --git a/docs/sections/blueprints/centos_vm.rst b/docs/sections/blueprints/centos_vm.rst
index b7e964c..cd2660e 100644
--- a/docs/sections/blueprints/centos_vm.rst
+++ b/docs/sections/blueprints/centos_vm.rst
@@ -1,23 +1,145 @@
 CentOS VM
 ======================
 
-Overview of my blueprint and the part it plays in DCAE.
+Note: This blueprint is intended to be deployed, automatically, as part of the
+DCAE bootstrap process, and is not normally invoked manually.
+
+This blueprint controls the deployment of a VM running the CentOS 7 operating system, used to
+run an instance of the Cloudify Manager orchestration engine.
+
+This blueprint is used to bootstrap an installation of Cloudify Manager.  All other DCAE 
+components are launched using Cloudify Manager.  The Cloudify Manager VM and the Cloudify Manager
+software are launched using the Cloudify command line software in its local mode.
 
 Blueprint files
 ----------------------
 
-List where we can find the blueprints
+The blueprint file is stored under source control in the ONAP ``dcaegen2.platform.blueprints`` project, in the ``blueprints``
+subdirectory of the project, as a template named ``centos_vm.yaml-template``.  The build process expands
+the template to fill in certain environment-specific values.  In the ONAP integration environment, the build process
+uploads the expanded template, using the name ``centos_vm.yaml``, to a well known-location in a Nexus artifact repository.
 
 Parameters
 ---------------------
 
-The input parameters needed for running the blueprint
+This blueprint has the following required input parameters:
+* ``centos7image_id``
+
+  This is the OpenStack image ID of the Centos7 VM image that will be
+  used to launch the Cloudify Manager VM.
+
+* ``ubuntu1604image_id``
+
+  This is not used by the blueprint but is specified here so that the blueprint
+  can use the same common inputs file as other DCAE VMs (which use an Ubuntu 16.04 image).
+
+* ``flavor_id``
+
+  This is the OpenStack flavor ID specifying the amount of memory, disk, and
+  CPU available to the Cloudify Manager VM.  While the required values will be
+  largely application dependent, a minimum of 16 Gigabytes of memory is
+  strongly recommended.
+
+* ``security_group``
+
+  This is the OpenStack security group specifying permitted inbound and
+  outbound IP connectivity to the VM.
+
+* ``public_net``
+
+  This is the name of the OpenStack network from which a floating IP address
+  for the VM will be allocated.
+
+* ``private_net``
+
+  This is the name of the OpenStack network from which fixed IP addresses for
+  the VM will be allocated.
+
+* ``openstack``
+
+  This is the JSON object / YAML associative array providing values necessary
+  for accessing OpenStack.  The keys are:
+
+  * ``auth_url``
+
+    The URL for accessing the OpenStack Identity V2 API.  (The version of
+    Cloudify currently being used, and the associated OpenStack plugin do
+    not currently support Identity V3).
+
+  * ``tenant_name``
+
+    The name of the OpenStack tenant/project where the VM will be launched.
+
+  * ``region``
+
+    The name of the OpenStack region within the deployment.  In smaller
+    OpenStack deployments, where there is only one region, the region is
+    often named ``RegionOne``.
+
+  * ``username``
+
+    The name of the OpenStack user used as a credential for accessing
+    OpenStack.
+
+  * ``password``
+
+    The password of the OpenStack user.  (The version of Cloudify currently
+    being used does not provide a mechanism for encrypting this value).
+
+* ``keypair``
+
+  The name of the ssh "key pair", within OpenStack, that will be given access,
+  via the ubuntu login, to the VMs.  Note: OpenStack actually stores only the
+  public key.
+
+* ``key_filename``
+
+  The full file path, on the Cloudify Manager VM,
+  of the ssh private key file corresponding to the ``keypair`` input parameter.
+
+* ``location_domain``
+
+  The DNS domain/zone for DNS entries associated with the VM.
+  If, for example, location_domain is ``dcae.example.com`` then the FQDN for
+  a VM with hostname ``abcd`` would be ``abcd.dcae.example.com`` and a DNS
+  lookup of that FQDN would lead an A (or AAAA) record giving the floating
+  IP address assigned to that VM.
+
+* ``location_prefix``
+
+  The hostname prefix for hostname of the VM.  The hostname
+  assigned to the VM is created by concatenating this prefix with a suffix
+  identifying the Cloudify Manager VM (``orcl00``).  If the location prefix is ``jupiter`` then the hostname of
+  the Cloudify Manager VM would be ``jupiterorcl00``.
+
+* ``codesource_url`` and ``codesource_version``
+
+  This is not used by the blueprint but is specified here so that the blueprint
+  can use the same common inputs file as other DCAE VMs.  Some of the other VMs use
+  combination of ``codesource_url`` and ``codesource_version`` to locate scripts 
+  that are used at installation time.
+* ``datacenter``
+
+  The datacenter name that is used by the DCAE Consul installation.  This is needed so that the Consul agent
+  installed on the Cloudify Manager VM can be configured to register itself to the Consul service discovery system.
+  
+This blueprint has the following optional inputs:
+
+* ``cname`` (default ``dcae-orcl``)
+
+  A DNS alias name for the Cloudify Manager VM.  In addition to creating a DNS A record for the Cloudify Manager VM,
+  the installation process also creates a CNAME record, using ``dcae-orcl`` by default as the alias.
+  For example, if the ``location_domain`` input is ``dcae.example.com``, the ``location_prefix`` input is ``jupiter``,
+  and the ``cname`` input is the default ``dcae-orcl``, then the installation process will create an A record for 
+  ``jupiterorcl00.dcae.example.com`` and a CNAME record for ``dcae-orcl.dcae.example.com`` that points to
+  ``jupiterorcl00.dcae.example.com``.
+
 
 How To Run
 ---------------------
 
-Cfy command for running the blueprint
+This blueprint is run as part of the bootstrapping process.  (See the ``dcaegen2.deployments`` project.) 
+Running it manually requires setting up a Cloudify 3.4 command line environment--something that's handled
+automatically by the bootstrap process.
 
-Additional Information
----------------------
-Any additional information that help other people understanding and using yor blueprint
+