OpenContrail What is routing instance and route target

What is Route Target ?
RT is used to transfer routes between VRF’s/VPNS.

http://ccieblog.co.uk/mpls/difference-between-the-rd-and-rt

In contrail, Each Virtual Network has one "routing instance" and "route target".
You can find it with rest api to contrail api server

a)
Get all infos of Virtual Network "38fff8c1-4090-4fe5-abb8-9cc7d4d1224f"
#curl http://192.168.56.102:8082/virtual-network/38fff8c1-4090-4fe5-abb8-9cc7d4d1224f

* This gives the "Routing Instance" and "Route Target" of this Virtual Network.

b)
Get all infos of Routing Instance "dd434f0d-3c58-47f8-8b4e-dab1ffc046b8"
#curl http://192.168.56.102:8082/routing-instance/dd434f0d-3c58-47f8-8b4e-dab1ffc046b8

* This gives the "Virtual Network" and "Route Target" of this Routing Instance.

c)
Get all infos of Route Target "1fb37c1b-9e1e-418a-ae0b-59228d64a978"
#curl http://192.168.56.102:8082/route-target/1fb37c1b-9e1e-418a-ae0b-59228d64a978

* This gives the "Virtual Network" and "Routing Instance" of this Route Target.

d)
How to See "import route targets" each Virtual Network's routing_instance.
How to View the BGP Peer Status on the Control Node Using control-node introspect

http://192.168.56.102:8083/Snh_BgpNeighborReq

* See the column named "import_targets" for import route targets of a Virtual Network's routing_instance.
* You can see something like
    - import_targets   
    - target:64512:10003
    - target:64512:8000001

e)
You can also see bgp route targets and its routes using following control-node introspect
http://192.168.56.102:8083/Snh_ShowRouteReq
http://192.168.56.102:8083/Snh_ShowRouteReq?x=bgp.rtarget.0