Trent Lloyd 5dee017f12 Support new style (and multiple) external networks
Switch the generated configuration to use "new" style external
networks when ext-port is not set.  In this case we configure
external_network_bridge = (intentionally blank),
gateway_external_network_id = (blank) and update the README with
information on using this new style of configuration.

The current template configures external networks by using the default
external_network_bridge=br-ex (implied when not set).  This activates
legacy code which assumes that a single external network exists on
that bridge and the L3 Agent directly plugs itself in.
provider:network_type, provider:physical_network and
provider:segmentation_id are ignored.  You cannot create multiple
networks and you cannot use segmented networks (e.g. VLAN)

By setting external_network_bridge = (intentionally blank) the L2
Agent handles the configuration instead, this allows us to create
multiple networks and also to use more complex network configurations
such as VLAN.  It is also possible to use the same physical connection
with different segmentation IDs for both internal and external
networks, as well as multiple external networks.

Legacy/existing configurations where ext-port is set generate the same
configuration as previous and should continue to work as before.  I do
not believe it to be easy to migrate existing setups to the "new"
style configuration automatically as changes to the neutron network
configuration may be required (specifically: provider:physical_network
will now be used when it was not before, and may not be correct) and
the physical port needs to be moved from br-ex to br-data which the
charm does not currently handle and is likely to error as it does not
attempt removal first.  Further work may be possible in this area.

For information about this new style of configuration being preferred,
see discussions in LP#1491668, LP#1525059 and
http://docs.openstack.org/liberty/networking-guide/scenario-classic-ovs.html

Change-Id: I8d2bb8098e080969e0445293b1ed79714b2c964f
Related-Bug: #1491668
Related-Bug: #1525059
Closes-Bug: #1536768
2016-06-14 17:45:47 +01:00

8.2 KiB

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 virtualize the network that Nova Compute instances plug into.

It's designed as a replacement for nova-network; however it does not yet support all of the features of 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...

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 neutron-gateway
juju add-relation neutron-gateway mysql
juju add-relation neutron-gateway rabbitmq-server
juju add-relation neutron-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

Port Configuration

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:

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

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

neutron-gateway:
    bridge-mappings:         physnet1:br-data external:br-ex
    data-port:               br-data:eth1 br-ex:eth2
neutron-api:
    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).

neutron-gateway:
    bridge-mappings:         physnet1:br-data
    data-port:               br-data:eth1
neutron-api:
    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 \
    floating
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 interfaces.

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 the charm's instance-mtu option can be used to reduce instance MTU via DHCP.

juju set neutron-gateway instance-mtu=1400

OpenStack upstream documentation recommends a MTU value of 1400: OpenStack documentation

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

Deploying from source

The minimum openstack-origin-git config required to deploy from source is:

openstack-origin-git: include-file://neutron-juno.yaml

neutron-juno.yaml
-----------------
repositories:
- {name: requirements,
   repository: 'git://github.com/openstack/requirements',
   branch: stable/juno}
- {name: neutron,
   repository: 'git://github.com/openstack/neutron',
   branch: stable/juno}

Note that there are only two 'name' values the charm knows about: 'requirements' and 'neutron'. These repositories must correspond to these 'name' values. Additionally, the requirements repository must be specified first and the neutron repository must be specified last. All other repositories are installed in the order in which they are specified.

The following is a full list of current tip repos (may not be up-to-date):

openstack-origin-git: include-file://neutron-master.yaml

neutron-master.yaml
-------------------
repositories:
- {name: requirements,
   repository: 'git://github.com/openstack/requirements',
   branch: master}
- {name: oslo-concurrency,
   repository: 'git://github.com/openstack/oslo.concurrency',
   branch: master}
- {name: oslo-config,
   repository: 'git://github.com/openstack/oslo.config',
   branch: master}
- {name: oslo-context,
   repository: 'git://github.com/openstack/oslo.context',
   branch: master}
- {name: oslo-db,
   repository: 'git://github.com/openstack/oslo.db',
   branch: master}
- {name: oslo-i18n,
   repository: 'git://github.com/openstack/oslo.i18n',
   branch: master}
- {name: oslo-messaging,
   repository: 'git://github.com/openstack/oslo.messaging',
   branch: master}
- {name: oslo-middleware,
   repository': 'git://github.com/openstack/oslo.middleware',
   branch: master}
- {name: oslo-rootwrap',
   repository: 'git://github.com/openstack/oslo.rootwrap',
   branch: master}
- {name: oslo-serialization,
   repository: 'git://github.com/openstack/oslo.serialization',
   branch: master}
- {name: oslo-utils,
   repository: 'git://github.com/openstack/oslo.utils',
   branch: master}
- {name: pbr,
   repository: 'git://github.com/openstack-dev/pbr',
   branch: master}
- {name: stevedore,
   repository: 'git://github.com/openstack/stevedore',
   branch: 'master'}
- {name: python-keystoneclient,
   repository: 'git://github.com/openstack/python-keystoneclient',
   branch: master}
- {name: python-neutronclient,
   repository: 'git://github.com/openstack/python-neutronclient',
   branch: master}
- {name: python-novaclient,
   repository': 'git://github.com/openstack/python-novaclient',
   branch: master}
- {name: keystonemiddleware,
   repository: 'git://github.com/openstack/keystonemiddleware',
   branch: master}
- {name: neutron-fwaas,
   repository': 'git://github.com/openstack/neutron-fwaas',
   branch: master}
- {name: neutron-lbaas,
   repository: 'git://github.com/openstack/neutron-lbaas',
   branch: master}
- {name: neutron-vpnaas,
   repository: 'git://github.com/openstack/neutron-vpnaas',
   branch: master}
- {name: neutron,
   repository: 'git://github.com/openstack/neutron',
   branch: master}