Neutron is a virtual network service for Openstack, and a part of
Netstack. Just like OpenStack Nova provides an API to dynamically
request and configure virtual servers, Neutron provides an API to
dynamically request and configure virtual networks. These networks
connect "interfaces" from other OpenStack services (e.g., virtual NICs
from Nova VMs). The Neutron API supports extensions to provide
advanced network capabilities (e.g., QoS, ACLs, network monitoring,
This charm provides the OpenStack Neutron Open vSwitch agent, managing
L2 connectivity on nova-compute services.


This subordinate charm provides the Neutron OpenvSwitch configuration for a compute node.

Once deployed it takes over the management of the Neutron base and plugin configuration on the compute node.


To deploy (partial deployment of linked charms only):

juju deploy rabbitmq-server
juju deploy neutron-api
juju deploy nova-compute
juju deploy neutron-openvswitch
juju add-relation neutron-openvswitch nova-compute
juju add-relation neutron-openvswitch neutron-api
juju add-relation neutron-openvswitch rabbitmq-server

Note that the rabbitmq-server can optionally be a different instance of the rabbitmq-server charm than used by OpenStack Nova:

juju deploy rabbitmq-server rmq-neutron
juju add-relation neutron-openvswitch rmq-neutron
juju add-relation neutron-api rmq-neutron

The neutron-api and neutron-openvswitch charms must be related to the same instance of the rabbitmq-server charm.


It should only be used with OpenStack Icehouse and above and requires a seperate neutron-api service to have been deployed.

Disabling security group management

WARNING: this feature allows you to effectively disable security on your cloud!

This charm has a configuration option to allow users to disable any per-instance security group management; this must used with neutron-security-groups enabled in the neutron-api charm and could be used to turn off security on selected set of compute nodes:

juju deploy neutron-openvswitch neutron-openvswitch-insecure
juju set neutron-openvswitch-insecure disable-security-groups=True prevent-arp-spoofing=False
juju deploy nova-compute nova-compute-insecure
juju add-relation nova-compute-insecure neutron-openvswitch-insecure

These compute nodes could then be accessed by cloud users via use of host aggregates with specific flavors to target instances to hypervisors with no per-instance security.

Network Spaces support

This charm supports the use of Juju Network Spaces, allowing the charm to be bound to network space configurations managed directly by Juju. This is only supported with Juju 2.0 and above.

Open vSwitch endpoints can be configured using the 'data' extra-binding, ensuring that tunnel traffic is routed across the correct host network interfaces:

juju deploy neutron-openvswitch --bind "data=data-space"

alternatively these can also be provided as part of a juju native bundle configuration:

  charm: cs:xenial/neutron-openvswitch
    data: data-space

NOTE: Spaces must be configured in the underlying provider prior to attempting to use them.

NOTE: Existing deployments using os-data-network configuration options will continue to function; this option is preferred over any network space binding provided if set.

DPDK fast packet processing support

For OpenStack Mitaka running on Ubuntu 16.04, its possible to use experimental DPDK userspace network acceleration with Open vSwitch and OpenStack.

Currently, this charm supports use of DPDK enabled devices in bridges supporting connectivity to provider networks.

To use DPDK, you'll need to have supported network cards in your server infrastructure (see dpdk-nics[DPDK documentation]); DPDK must be enabled and configured during deployment of the charm, for example:

    enable-dpdk: True
    data-port: "br-phynet1:a8:9d:21:cf:93:fc br-phynet2:a8:9d:21:cf:93:fd br-phynet3:a8:9d:21:cf:93:fe"

As devices are not typically named consistently across servers, multiple instances of each bridge -> mac address mapping can be provided; the charm deals with resolution of the set of bridge -> port mappings that are required for each individual unit of the charm.

DPDK requires the use of hugepages, which is not directly configured in the neutron-openvswitch charm; Hugepage configuration can either be done by providing kernel boot command line options for individual servers using MAAS or using the 'hugepages' configuration option of the nova-compute charm:

    hugepages: 50%

By default, the charm will configure Open vSwitch/DPDK to consume a processor core + 1G of RAM from each NUMA node on the unit being deployed; this can be tuned using the dpdk-socket-memory and dpdk-socket-cores configuration options of the charm. The userspace kernel driver can be configured using the dpdk-driver option. See config.yaml for more details.

NOTE: Changing dpdk-socket-* configuration options will trigger a restart of Open vSwitch, which currently causes connectivity to running instances to be lost - connectivity can only be restored with a stop/start of each instance.

NOTE: Enabling DPDK support automatically disables security groups for instances.

Port Configuration

NOTE: External port configuration only applies when DVR mode is enabled.

All network types (internal, external) are configured with bridge-mappings and
data-port and the flat-network-providers configuration option of the
neutron-api charm. Once deployed, you can configure the network specifics
using neutron net-create.

If the device name is not consistent between hosts, you can specify the same
bridge multiple times with MAC addresses instead of interface names. The charm
will loop through the list and configure the first matching interface.

Basic configuration of a single external network, typically used as floating IP
addresses combined with a GRE private network:

    bridge-mappings:         physnet1:br-ex
    data-port:               br-ex:eth1
    flat-network-providers:  physnet1

neutron net-create --provider:network_type flat \
    --provider:physical_network physnet1 --router:external=true \
neutron router-gateway-set provider external

Alternative configuration with two networks, where the internal private
network is directly connected to the gateway with public IP addresses but a
floating IP address range is also offered.

    bridge-mappings:         physnet1:br-data external:br-ex
    data-port:               br-data:eth1 br-ex:eth2
    flat-network-providers:  physnet1 external

Alternative configuration with two external networks, one for public instance
addresses and one for floating IP addresses. Both networks are on the same
physical network connection (but they might be on different VLANs, that is
configured later using neutron net-create).

    bridge-mappings:         physnet1:br-data
    data-port:               br-data:eth1
    flat-network-providers:  physnet1

neutron net-create --provider:network_type vlan \
    --provider:segmentation_id 400 \
    --provider:physical_network physnet1 --shared external
neutron net-create --provider:network_type vlan \
    --provider:segmentation_id 401 \
    --provider:physical_network physnet1 --shared --router:external=true \
neutron router-gateway-set provider floating

This replaces the previous system of using ext-port, which always created a bridge
called br-ex for external networks which was used implicitly by external router


                            The IP address and netmask of the OpenStack Data network (e.g.,
This network will be used for tenant network traffic in overlay
In order to support service zones spanning multiple network
segments, a space-delimited list of a.b.c.d/x can be provided
The address of the first network found to have an address
configured will be used.

                            Kernel userspace device driver to use for DPDK devices, valid values include:
Only used when DPDK is enabled.

                            Enable suppression of ARP responses that don't match an IP address that belongs
to the port from which they originate.
Only supported in OpenStack Liberty or newer, which has the required minimum version
of Open vSwitch.

                            Specifies a default OpenStack release name, or a YAML dictionary
listing the git repositories to install from.

The default Openstack release name may be one of the following, where
the corresponding OpenStack github branch will be used:
  * liberty
  * mitaka
  * master

The YAML must minimally include requirements, neutron-fwaas,
neutron-lbaas, neutron-vpnaas, and neutron repositories, and may
also include repositories for other dependencies:
  - {name: requirements,
     repository: 'git://',
     branch: master}
  - {name: neutron-fwaas,
     repository: 'git://',
     branch: master}
  - {name: neutron-lbaas,
     repository: 'git://',
     branch: master}
  - {name: neutron-vpnaas,
     repository: 'git://',
     branch: master}
  - {name: neutron,
     repository: 'git://',
     branch: master}
  release: master

                            Amount of hugepage memory in MB to allocate per NUMA socket in deployed systems.
Only used when DPDK is enabled.

                            Username used to access RabbitMQ queue
                            Disable neutron based security groups - setting this configuration option
will override any settings configured via the neutron-api charm.
BE CAREFUL - this option allows you to disable all port level security
within an OpenStack cloud.

                            Setting this to True will allow supporting services to log to syslog.

                            Space-delimited list of bridge:port mappings. Ports will be added to
their corresponding bridge. The bridges will allow usage of flat or
VLAN network types with Neutron and should match this defined in
Ports provided can be the name or MAC address of the interface to be
added to the bridge. If MAC addresses are used, you may provide multiple
bridge:mac for the same bridge so as to be able to configure multiple
units. In this case the charm will run through the provided MAC addresses
for each bridge until it finds one it can resolve to an interface name.

                            Enable DPDK fast userspace networking; this requires use of DPDK supported network
interface drivers and must be used in conjuction with the data-port configuration
option to configure each bridge with an appropriate DPDK enabled network device.

                            RabbitMQ vhost
                            Number of cores to allocate to DPDK per NUMA socket in deployed systems.
Only used when DPDK is enabled.

                            Enable local Neutron DHCP and Metadata Agents. This is useful for deployments
which do not include a neutron-gateway (do not require l3, lbaas or vpnaas
services) and should only be used in-conjunction with flat or VLAN provider
networks configurations.

                            Enable debug logging.
                            Enable verbose logging.
                            Space-delimited list of ML2 data bridge mappings with format

                            Space-delimited list of Neutron flat network providers.

                            Space-delimited list of <physical_network>:<vlan_min>:<vlan_max> or
<physical_network> specifying physical_network names usable for VLAN
provider and tenant networks, as well as ranges of VLAN tags on each
available for allocation to tenant networks.

                            Deprecated: Use bridge-mappings and data-port to create a network
which can be used for external connectivity.  You can call the network
external and the bridge br-ex by convention, but neither is required

A space-separated list of external ports to use for routing of instance
traffic to the external public network. Valid values are either MAC
addresses (in which case only MAC addresses for interfaces without an IP
address already assigned will be used), or interfaces (eth0)