From 830c02b77fd94c97cc9f06230edcef28c6436dda Mon Sep 17 00:00:00 2001
From: Arvind Somya <asomya@cisco.com>
Date: Tue, 22 Apr 2014 08:02:22 -0700
Subject: [PATCH] L3 router Service plugin for the Cisco APIC

Specification for a new Layer 3 router service plugin for the
Application Centric Infrastructure Controller (APIC).

Change-Id: I270f6be97bb7c64f3a662b96fe003bee3343835c
---
 specs/juno/apic-l3-service-plugin.rst | 134 ++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 specs/juno/apic-l3-service-plugin.rst

diff --git a/specs/juno/apic-l3-service-plugin.rst b/specs/juno/apic-l3-service-plugin.rst
new file mode 100644
index 000000000..c8485625c
--- /dev/null
+++ b/specs/juno/apic-l3-service-plugin.rst
@@ -0,0 +1,134 @@
+=============================================
+Layer 3 service plugin for the Cisco APIC
+=============================================
+
+https://blueprints.launchpad.net/neutron/+spec/cisco-apic-l3
+
+This blueprint is to implement Layer 3 features in
+the network fabric via a L3 router service plugin
+using the Cisco APIC.
+
+Flows
+
+.. blockdiag::
+
+  blockdiag l2_apic {
+    Neutron -> APIC -> Nexus_9k;
+    Nexus_9k -> Compute1;
+    Nexus_9k -> Compute2;
+  }
+
+Problem description
+===================
+
+The APIC (Application Policy Infrastructure Controller) together with
+Cisco Nexus 9000 switches provides programmable, policy-driven network
+control.
+
+The Service plugin proposed will interact with the APIC to dynamically
+configure Layer 3 inter and intra tenant communications in the network fabric.
+
+
+Proposed change
+===============
+
+This proposal is to introduce a new Layer 3 service plugin that communicates
+with the APIC.
+
+The driver implements the following neutron events:
+* Add a new router interface
+* Delete a router interface
+
+The plugin will implement Layer 3 communications using a construct called
+a contract that provides communications in the fabric between various
+end point groups (Neutron networks)
+
+Events that trigger the creation of end point groups and subnets (i.e. 
+create_network and create_subnet) will be handled by the APIC ML2 mechanism
+driver and id’s will be stored in a database accessed by a common client and
+manager class.
+
+Due to hardware limitations as of this writing this service plugin will
+only handle add/remove router_interface (internal gateway) events. The service
+plugin may be expanded in the future to also handle all neutron L3 events.
+
+Alternatives
+------------
+The alternative approach is to use the open source agent based layer 3 router
+plugin. The agent based approach does not implement any policies that are
+centric to the APIC’s ACI (Application Centric Infrastructure) based design.
+
+Data model impact
+-----------------
+n.a.
+
+REST API impact
+---------------
+n.a
+
+Security impact
+---------------
+n.a
+
+Notifications impact
+--------------------
+n.a.
+
+Other end user impact
+---------------------
+n.a.
+
+Performance Impact
+------------------
+The service plugin is triggered instead of polled, there are no
+changes to any existing code patterns. The potential bottleneck
+for this plugin would be the link between neutron and the APIC.
+
+Other deployer impact
+---------------------
+There are no config options specific to the Layer 3 plugin, it relies
+on the configuration options of the ML2 apic mechanism driver.
+
+Developer impact
+----------------
+n.a.
+
+
+Implementation
+==============
+
+Assignee(s)
+-----------
+
+Arvind Somya <asomya>
+
+Work Items
+----------
+Single work item for the L3 APIC service plugin.
+
+
+Dependencies
+============
+Depends on the APIC ML2 blueprint:
+https://blueprints.launchpad.net/neutron/+spec/ml2-cisco-apic-mechanism-driver
+
+
+Testing
+=======
+Complete unit test coverage of the code is included.
+
+For tempest test coverage, third party testing is provided. The Cisco
+CI reports on all changes affecting this driver. The testing is run in
+a setup with an OpenStack deployment (devstack) connected to a live
+APIC and a Cisco Nexus 9000 physical switch.
+
+
+Documentation Impact
+====================
+Deployment documentation on how to configure and deploy this service plugin
+will be documented in the Openstack wiki.
+
+
+References
+==========
+http://www.cisco.com/go/apic