[openstack-ansible] Dedicated gateway hosts not working with OVN

2 Sep 2023

      Hello,

We have deployed an openstack-ansible cluster to test it on_metal with OVN
and defined *dedicated gateway hosts* connecting to the external network
with the *network-gateway_hosts* host group. Unfortunately, we are not able
to connect to the external/provider networks. It seems that traffic wants
to reach external networks via the hypervisor nodes and not the gateway
hosts.

Any suggestions on changes needed to our configuration will be highly
appreciated.

Environment:
-Openstack Antelope
-Ubuntu 22 on all hosts
-3 infra hosts - 1xNIC (ens1)
-2 compute hosts - 1xNIC (ens1)
-2 gateway hosts - 2xNIC (ens1 internal, ens2 external)
-No linux bridges are created.

The gateway hosts are the only ones physically connected to the external
network via physical interface ens2. Therefore, we need all external
provider network traffic to traverse via these gateway hosts.

Tenant networks work fine and VMs can talk to each other. However, when a
VM is spawned with a floating IP to the external network, they are unable
to reach the outside network.

Relevant content from openstack-ansible configuration files:

=.=.=.=.=.=.=.=
openstack_user_config.yml
=.=.=.=.=.=.=.=
```
...
provider_networks:
    - network:
        container_bridge: "br-mgmt"
        container_type: "veth"
        container_interface: "ens1"
        ip_from_q: "management"
        type: "raw"
        group_binds:
          - all_containers
          - hosts
        is_management_address: true
    - network:
        container_bridge: "br-vxlan"
        container_type: "veth"
        container_interface: "ens1"
        ip_from_q: "tunnel"
        #type: "vxlan"
        type: "geneve"
        range: "1:1000"
        net_name: "geneve"
        group_binds:
          - neutron_ovn_controller
    - network:
        container_bridge: "br-flat"
        container_type: "veth"
        container_interface: "ens1"
        type: "flat"
        net_name: "flat"
        group_binds:
          - neutron_ovn_controller
    - network:
        container_bridge: "br-vlan"
        container_type: "veth"
        container_interface: "ens1"
        type: "vlan"
        range: "101:300,401:500"
        net_name: "vlan"
        group_binds:
          - neutron_ovn_controller
    - network:
        container_bridge: "br-storage"
        container_type: "veth"
        container_interface: "ens1"
        ip_from_q: "storage"
        type: "raw"
        group_binds:
          - glance_api
          - cinder_api
          - cinder_volume
          - nova_compute

...

compute-infra_hosts:
  inf1:
    ip: 172.16.0.1
  inf2:
    ip: 172.16.0.2
  inf3:
    ip: 172.16.0.3

compute_hosts:
  cmp4:
    ip: 172.16.0.21
  cmp3:
    ip: 172.16.0.22

network_hosts:
  inf1:
    ip: 172.16.0.1
  inf2:
    ip: 172.16.0.2
  inf3:
    ip: 172.16.0.3

network-gateway_hosts:
  net1:
    ip: 172.16.0.31
  net2:
    ip: 172.16.0.32

```

=.=.=.=.=.=.=.=
user_variables.yml
=.=.=.=.=.=.=.=
```
---
debug: false
install_method: source
rabbitmq_use_ssl: False
haproxy_use_keepalived: False
...
neutron_plugin_type: ml2.ovn
neutron_plugin_base:
  - neutron.services.ovn_l3.plugin.OVNL3RouterPlugin

neutron_ml2_drivers_type: geneve,vlan,flat
neutron_ml2_conf_ini_overrides:
  ml2:
    tenant_network_types: geneve

...
```

=.=.=.=.=.=.=.=
env.d/neutron.yml
=.=.=.=.=.=.=.=
```
component_skel:
  neutron_ovn_controller:
    belongs_to:
      - neutron_all
  neutron_ovn_northd:
    belongs_to:
      - neutron_all

container_skel:
  neutron_agents_container:
    contains: {}
  properties:
    is_metal: true
  neutron_ovn_northd_container:
    belongs_to:
      - network_containers
    contains:
      - neutron_ovn_northd

```

=.=.=.=.=.=.=.=
env.d/nova.yml
=.=.=.=.=.=.=.=
```
component_skel:
  nova_compute_container:
    belongs_to:
      - compute_containers
      - kvm-compute_containers
      - lxd-compute_containers
      - qemu-compute_containers
    contains:
      - neutron_ovn_controller
      - nova_compute
    properties:
      is_metal: true
```

=.=.=.=.=.=.=.=
group_vars/network_hosts
=.=.=.=.=.=.=.=
```
openstack_host_specific_kernel_modules:
  - name: "openvswitch"
    pattern: "CONFIG_OPENVSWITCH"
```

The nodes layout is like this:

 [image: image.png]

Any guidance on what we have wrong or how to improve this configuration
will be appreciated. We need to make external traffic for VMs to go out via
the gateway nodes and not the compute/hypervisor nodes.

Thank you.

Roger

[openstack-ansible] Dedicated gateway hosts not working with OVN

Roger Rivera