Second BPG DT

Includes:
- BGP
- Networker nodes
- DVR
- expose-tenant-networks disabled
- ovn routing
- NBDB driver
- FRR: IP-level BGP peers
- FRR: different ASN per rack
- Tempest (neutron+octavia) + Tobiko (scenario+sanity+faults)

examples/dt/bgp/ovn-routing-nbdb-driver/README.md

@@ -0,0 +1,55 @@
+# RHOSO Deployed Topology - BGP using kernel routing and OVN NB DB driver
+
+## General information
+| Revision | Change                | Date             |
+|--------: | :-------------------- | :--------------: |
+| v0.1     | Initial publication   | 2024-01-12       |
+
+## Node topology
+| Node role                                     | bm/vm | amount |
+| --------------------------------------------- | ----- | ------ |
+| Openshift master/worker combo-node cluster    | vm    | 3      |
+| Compute nodes                                 | vm    | 3      |
+| Networker nodes                               | vm    | 3      |
+| Leaf routers                                  | vm    | 6      |
+| Spine routers                                 | vm    | 2      |
+| External routers                              | vm    | 1      |
+| External VMs                                  | vm    | 1      |
+
+## Services, enabled features and configurations
+| Service                                     | configuration                                                                                  | Lock-in coverage?  |
+| ------------------------------------------- | ---------------------------------------------------------------------------------------------- | ------------------ |
+| Neutron                                     | ML2/OVN, DVR                                                                                   | Must have          |
+| Octavia                                     |                                                                                                | Must have          |
+| OVN-BGP-Agent                               | ovn-routing, nbdb-driver expose-tenant-networks disabled, sync-interval set to a high value    | Must have          |
+| FRR                                         | different ASN per rack, IP-level BGP peers                                                     | Must have          |
+
+## Considerations/Constraints
+1. Virtual networks should be created to connect the VMs between them.
+2. All the VMs that are neither Openstack nor Openshift nodes need to be
+   properly configured in order to support the BGP protocol.
+3. The spine/leaf topology separates the overcloud nodes into different L2
+   network segments, called racks. Each rack includes one compute, one
+   networker and two leafs.
+4. A separate provisioning network is necessary to install Openstack on those
+   nodes.
+5. Once Openstack is installed on them, controlplane and dataplane connectivity
+   between them and with external machines (extvm) is achieved with the BGP
+   protocol.
+6. Tests are executed from the extvm machine, in order to verify external
+   connectivity.
+
+## Testing tree
+| Test framework           | Stage to run | Special configuration                                                 | Test case to report      |
+| ------------------------ | ------------ | --------------------------------------------------------------------- | :----------------------: |
+| Tempest/neutron+octavia  | stage 5      | skips due to usupported features (multicast, FIP port-forwarding, etc)| scenario                 |
+| Tobiko/Faults            | stage 6      |                                                                       | sanity, scenario, faults |
+
+## Stages
+All stages must be executed in the order listed below.  Everything is required unless otherwise indicated.
+1. [Pre-deployment: create virtual networks, virtual routers and nodes](bgp-pre-deplyment.md)
+2. [Install the OpenStack K8S operators and their dependencies](../../common/)
+3. [Configure networking and deploy the Openstack control plane](bgp-control-plane.md)
+4. [Configure and deploy the data plane](bgp-data-plane)
+5. [Execute non destructive testing](bgp-tempest.md)
+6. [Execute HA testing](bgp-tobiko.md)