Neutron Gateway

Overview

The neutron-gateway charm deploys the data plane of Neutron, the core OpenStack service that provides software defined networking (SDN) for Nova instances. This provides the Neutron Gateway service, which in turn supplies two key services: L3 network routing and DHCP. The charm works alongside other Juju-deployed OpenStack applications; in particular: neutron-openvswitch, nova-compute, and nova-cloud-controller.

Note: Starting with OpenStack Train, the neutron-gateway and neutron-openvswitch charm combination can be replaced by the OVN charms (e.g. ovn-central, ovn-chassis, and neutron-api-plugin-ovn).

Usage

Configuration

This section covers common and/or important configuration options. See file config.yaml for the full list of options, along with their descriptions and default values. See the Juju documentation for details on configuring applications.

data-port

A bridge that Neutron Gateway will bind to, given in the form of a space-delimited bridge:port mapping (e.g. 'br-ex:ens8'). The port will be added to its corresponding bridge.

Note: If network device names are not consistent between hosts (e.g. 'eth1' and 'ens8') a list of values can be provided where a MAC address is used in the place of a device name. The charm will iterate through the list and configure the first matching interface.

The specified bridge(s) should match the one(s) defined in the bridge-mappings option.

Flat or VLAN network types are supported.

The device itself must not have any L3 configuration. In MAAS, it must have an IP mode of 'Unconfigured'.

bridge-mappings

A space-delimited list of ML2 data provider:bridge mappings (e.g. 'physnet1:br-ex'). The specified bridge(s) should match the one(s) defined in the data-port option.

openstack-origin

The openstack-origin option states the software sources. A common value is an OpenStack UCA release (e.g. 'cloud:bionic-ussuri' or 'cloud:focal-victoria'). See Ubuntu Cloud Archive. The underlying host's existing apt sources will be used if this option is not specified (this behaviour can be explicitly chosen by using the value of 'distro').

Deployment

These deployment instructions assume the following pre-existing applications: neutron-api, nova-cloud-controller, and rabbitmq-server.

Important: For Neutron Gateway to function properly, the nova-cloud-controller charm must have its network-manager option set to 'Neutron'.

Deploy Neutron Gateway:

juju deploy neutron-gateway
juju add-relation neutron-gateway:quantum-network-service nova-cloud-controller:quantum-network-service
juju add-relation neutron-gateway:neutron-plugin-api neutron-api:neutron-plugin-api
juju add-relation neutron-gateway:amqp rabbitmq-server:amqp

Port configuration

Network ports are configured with the bridge-mappings and data-port options but the neutron-api charm also has several relevant options (e.g. flat-network-providers, vlan-ranges, etc.). Additionally, the network topology can be further defined with supplementary openstack client commands.