Add documentation on deploying Designate

There are some additional steps required to deploy Designate and
this new document explains them.

Change-Id: Idc6499aadd917a59218dd122c4b1830c8912535a

doc/source/install/advanced_deployment/designate.rst

@@ -0,0 +1,63 @@
+Deploying DNSaaS (Designate)
+============================
+
+Because some aspects of a Designate deployment are specific to the environment
+in which it is deployed, there is some additional configuration required
+beyond just including an environment file.  The following instructions will
+explain this configuration.
+
+First, make a copy of the ``designate-config.yaml`` environment.
+
+.. note:: For HA deployments, there is a separate ``designate-config-ha.yaml``
+          file that should be used instead.
+
+::
+
+    cp /usr/share/openstack-tripleo-heat-templates/environments/designate-config.yaml .
+
+This file contains a sample pool configuration which must be edited to match
+the intended environment.  Each section has comments that explain how to
+configure it.
+
+.. TODO(bnemec): Include these notes in the sample environments, or figure
+                 out how to pull these values from the Heat stack and populate
+                 the file automatically.
+
+* ``ns_records``: There should be one of these for each node running designate,
+                  and they should point at the public IP of the node.
+* ``nameservers``: There should be one of these for each node running BIND.
+                   The ``host`` value should be the public IP of the node.
+* ``targets``: There should be one of these for each node running BIND.  Each
+               target has the following attributes which need to be configured:
+
+  * ``masters``: There should be one of these for each node running
+                 designate-mdns.  The ``host`` value should be the public IP
+                 of the node.
+  * ``options``: This specifies where the target BIND instance will be
+                 listening.  ``host`` should be the public IP of the node, and
+                 ``rndc_host`` should be the internal_api IP of the node.
+
+Because this configuration requires the node IPs to be known ahead of time, it
+is necessary to use predictable IPs.  Full details on configuring those can be
+found at :doc:`node_placement`.
+
+Only the external (public) and internal_api networks need to be predictable
+for Designate.  The following is an example of the addresses that need to be
+set::
+
+    parameter_defaults:
+      ControllerIPs:
+        external:
+        - 10.0.0.51
+        - 10.0.0.52
+        - 10.0.0.53
+        internal_api:
+        - 172.17.0.251
+        - 172.17.0.252
+        - 172.17.0.253
+
+Include ``enable-designate.yaml``, ``ips-from-pool.yaml``, and either
+``designate-config.yaml`` or ``designate-config-ha.yaml`` in the deploy
+command::
+
+    openstack overcloud deploy --templates -e /usr/share/openstack-tripleo-heat-templates/environments/enable-designate.yaml -e ips-from-pool.yaml -e designate-config.yaml [...]

doc/source/install/advanced_deployment/features.rst

@@ -29,3 +29,4 @@ Documentation on how to enable and configure various features available in
    split_stack
    ansible_config_download_differences
    rhsm
+   designate