Overview

Neutron provides flexible software defined networking (SDN) for OpenStack.

This charm is designed to be used in conjunction with the rest of the OpenStack related charms in the charm store) to virtualized the network that Nova Compute instances plug into.

Its designed as a replacement for nova-network; however it does not yet support all of the features as nova-network (such as multihost) so may not be suitable for all.

Neutron supports a rich plugin/extension framework for propriety networking solutions and supports (in core) Nicira NVP, NEC, Cisco and others...

The Openstack charms currently only support the fully free OpenvSwitch plugin and implements the 'Provider Router with Private Networks' use case.

See the upstream Neutron documentation for more details.

Usage

In order to use Neutron with Openstack, you will need to deploy the nova-compute and nova-cloud-controller charms with the network-manager configuration set to 'Neutron':

nova-cloud-controller:
    network-manager: Neutron

This decision must be made prior to deploying Openstack with Juju as Neutron is deployed baked into these charms from install onwards:

juju deploy nova-compute
juju deploy --config config.yaml nova-cloud-controller
juju add-relation nova-compute nova-cloud-controller

The Neutron Gateway can then be added to the deploying:

juju deploy quantum-gateway
juju add-relation quantum-gateway mysql
juju add-relation quantum-gateway rabbitmq-server
juju add-relation quantum-gateway nova-cloud-controller

The gateway provides two key services; L3 network routing and DHCP services.

These are both required in a fully functional Neutron Openstack deployment.

See upstream Neutron multi extnet

Configuration Options

External Port Configuration

If the port to be used for external traffic is consistent accross all physical servers then is can be specified by simply setting ext-port to the nic id:

quantum-gateway:
    ext-port: eth2

However, if it varies between hosts then the mac addresses of the external nics for each host can be passed as a space seperated list:

quantum-gateway:
    ext-port: <MAC ext port host 1> <MAC ext port host 2> <MAC ext port host 3>

Multiple Floating Pools

If multiple floating pools are needed then an L3 agent (which corresponds to a quantum-gateway for the sake of this charm) is needed for each one. Each gateway needs to be deployed as a seperate service so that the external network id can be set differently for each gateway e.g.

juju deploy quantum-gateway quantum-gateway-extnet1
juju add-relation quantum-gateway-extnet1 mysql
juju add-relation quantum-gateway-extnet1 rabbitmq-server
juju add-relation quantum-gateway-extnet1 nova-cloud-controller
juju deploy quantum-gateway quantum-gateway-extnet2
juju add-relation quantum-gateway-extnet2 mysql
juju add-relation quantum-gateway-extnet2 rabbitmq-server
juju add-relation quantum-gateway-extnet2 nova-cloud-controller

Create extnet1 and extnet2 via neutron client and take a note of their ids

juju set quantum-gateway-extnet1 "run-internal-router=leader"
juju set quantum-gateway-extnet2 "run-internal-router=none"
juju set quantum-gateway-extnet1 "external-network-id=<extnet1 id>"
juju set quantum-gateway-extnet2 "external-network-id=<extnet2 id>"

Instance MTU

When using Open vSwitch plugin with GRE tunnels default MTU of 1500 can cause packet fragmentation due to GRE overhead. One solution is to increase the MTU on physical hosts and network equipment. When this is not possible or practical thi charm's instance-mtu option can be used to reduce instance MTU via DHCP.

juju set quantum-gateway instance-mtu=1400

OpenStack upstream documentation recomments a MTU value of 1400: Openstack documentation

Note that this option was added in Havana and will be ignored in older releases.

TODO

• Provide more network configuration use cases.
• Support VLAN in addition to GRE+OpenFlow for L2 separation.