Red Hat OpenStack and Contrail Networking Integration in Contrail Cloud
Contrail Cloud uses Contrail Networking as the SDN controller and Red Hat OpenStack as the orchestration platform. This section covers how Red Hat Openstack and Contrail Networking integrate in a Contrail Cloud environment. This section assumes some existing knowledge of Contrail Cloud and Red Hat Openstack components. The Contrail Cloud components are largely discussed in the later sections of this documentation. The RedHat components used in Contrail Cloud are listed in the Contrail Cloud Software Summary. See Product Documentation for Red Hat OpenStack Platform 13 for additional information on the Red Hat Openstack components.
Figure 1 illustrates the API-level interaction between OpenStack and Contrail Networking configurations. The Contrail Neutron plug-in enables the OpenStack Neutron service to make the necessary API calls into the Contrail configuration node to create, delete, and update network resources as defined in OpenStack. The Contrail configuration node has a northbound interface which exposes REST APIs to orchestration systems such as OpenStack and Contrail Web UI that can be used to make the network configurations.
Figure 2 illustrates a more detailed step-by-step interaction between components of OpenStack services, specifically Nova, Neutron, and Contrail services. At the control plane the Contrail plug-in for Neutron translates the configuration commands received from the northbound orchestration engines into corresponding Contrail-related configuration. On the data plane or forwarding plane, the Nova-agent running on each compute hypervisor interacts with the distributed forwarding engine in Contrail Networking, called the vRouter, to set up a virtual-interface and tap interfaces for VMs to obtain connectivity.
