Add docs on Neutron DVR support

Change-Id: Ie549944a6fde877b19e1739355664fe5177b89cc

doc/source/enable_neutron_dvr.rst

@@ -0,0 +1,117 @@
+.. _enable_neutron_dvr:
+
+=============================================
+Enable Distributed Virtual Routing in Neutron
+=============================================
+
+This guide provides an instruction for enabling DVR support in a
+CCP deployment.
+
+.. NOTE:: DVR mode applies only for Neutron reference implementation with
+   ML2/OpenVSwitch plugin. In order to determine distributed routing
+   capabilities of other plugins/drivers please refer to their corresponding
+   documentation.
+
+Introduction
+============
+
+DVR
+---
+
+* Distributes L3 Routers across compute nodes when required by VMs
+* L3 and Metadata Agents are running on each and every compute node
+* Inter-subnets traffic is no longer affected by performance of one
+  node with l3 agent
+* Traffic for VMs with floating IP is no longer affected by performance
+  of one node with l3 agent
+* Removal of single l3 agent node as single-point-of-failure for all
+  inter-tenant traffic and Floating IP traffic
+
+.. image:: neutron_with_dvr.png
+     :height: 230 px
+     :width: 600 px
+
+Sample CCP configuration
+========================
+
+ccp.yaml may look like:
+
+::
+
+    builder:
+      push: True
+    registry:
+      address: "127.0.0.1:31500"
+    repositories:
+      skip_empty: True
+    services:
+      database:
+        service_def: galera
+      rpc:
+        service_def: rabbitmq
+      notifications:
+        service_def: rabbitmq
+    nodes:
+      node1:
+        roles:
+          - db
+          - messaging
+          - controller
+          - openvswitch
+      node[2-3]:
+        roles:
+          - db
+          - messaging
+          - compute
+          - openvswitch
+    roles:
+      db:
+        - database
+      messaging:
+        - rpc
+        - notifications
+      controller:
+        - etcd
+        - glance-api
+        - glance-registry
+        - heat-api-cfn
+        - heat-api
+        - heat-engine
+        - horizon
+        - keystone
+        - memcached
+        - neutron-dhcp-agent
+        - neutron-l3-agent
+        - neutron-metadata-agent
+        - neutron-server
+        - nova-api
+        - nova-conductor
+        - nova-consoleauth
+        - nova-novncproxy
+        - nova-scheduler
+      compute:
+        - nova-compute
+        - nova-libvirt
+        - neutron-l3-agent-compute
+        - neutron-metadata-agent
+      openvswitch:
+        - neutron-openvswitch-agent
+        - openvswitch-db
+        - openvswitch-vswitchd
+    configs:
+        private_interface: ens7
+        public_interface: ens7
+        neutron:
+          dvr: True
+          physnets:
+            - name: "physnet1"
+              bridge_name: "br-ex"
+              interface: "ens3"
+              flat: true
+              vlan_range: false
+
+Compute node now has 2 additional roles:
+neutron-l3-agent-compute and neutron-metadata-agent.
+
+.. NOTE:: For Floating IPs to work properly, DVR requires each compute node
+   to have access to the external net.

doc/source/index.rst

@@ -30,6 +30,7 @@ Advanced topics
    ceph
    ceph_cluster
    enable_sriov
+   enable_neutron_dvr
    using_calico_instead_of_ovs
    using_odl_instead_of_ovs
    ironic