Installation¶
The networking-ovn repository includes integration with DevStack that
enables creation of a simple Open Virtual Network (OVN) development and test
environment. This document discusses what is required for manual installation
or integration into a production OpenStack deployment tool of conventional
architectures that include the following types of nodes:
Controller - Runs OpenStack control plane services such as REST APIs and databases.
Network - Runs the layer-2, layer-3 (routing), DHCP, and metadata agents for the Networking service. Some agents optional. Usually provides connectivity between provider (public) and project (private) networks via NAT and floating IP addresses.
Note
Some tools deploy these services on controller nodes.
Compute - Runs the hypervisor and layer-2 agent for the Networking service.
Packaging¶
Open vSwitch (OVS) includes OVN beginning with version 2.5 and considers
it experimental. The Networking service integration for OVN uses an
independent package, typically networking-ovn.
Building OVS from source automatically installs OVN. For deployment tools
using distribution packages, the openvswitch-ovn package for RHEL/CentOS
and compatible distributions automatically installs openvswitch as a
dependency. Ubuntu/Debian includes ovn-central, ovn-host,
ovn-docker, and ovn-common packages that pull in the appropriate Open
vSwitch dependencies as needed.
A python-networking-ovn RPM may be obtained for Fedora or CentOS from
the RDO project. A package based on the master branch of
networking-ovn can be found at http://trunk.rdoproject.org/.
Fedora and CentOS RPM builds of OVS and OVN from the master branch of
ovs can be found in this COPR repository:
https://copr.fedorainfracloud.org/coprs/leifmadsen/ovs-master/. If you would
like packages that are built with DPDK integration enabled, you can try this
COPR repository, instead:
https://copr.fedorainfracloud.org/coprs/pmatilai/dpdk-snapshot/.
Controller nodes¶
Each controller node runs the OVS service (including dependent services such
as ovsdb-server) and the ovn-northd service. However, only a single
instance of the ovsdb-server and ovn-northd services can operate in
a deployment. However, deployment tools can implement active/passive
high-availability using a management tool that monitors service health
and automatically starts these services on another node after failure of the
primary node. See the FAQ for more information.
Install the
openvswitch-ovnandnetworking-ovnpackages.Start the OVS service. The central OVS service starts the
ovsdb-serverservice that manages OVN databases.Using the systemd unit:
# systemctl start openvswitchUsing the
ovs-ctlscript:# /usr/share/openvswitch/scripts/ovs-ctl start --system-id="random"
Configure the
ovsdb-servercomponent. By default, theovsdb-serverservice only permits local access to databases via Unix socket. However, OVN services on compute nodes require access to these databases.Permit remote database access.
# ovs-appctl -t ovsdb-server ovsdb-server/add-remote ptcp:6640:IP_ADDRESSReplace
IP_ADDRESSwith the IP address of the management network interface on the controller node.Note
Permit remote access to TCP port 6640 on any host firewall.
Start the
ovn-northdservice.Using the systemd unit:
# systemctl start ovn-northdUsing the
ovn-ctlscript:# /usr/share/openvswitch/scripts/ovn-ctl start_northdOptions for start_northd:
# /usr/share/openvswitch/scripts/ovn-ctl start_northd --help # ... # DB_NB_SOCK="/usr/local/etc/openvswitch/nb_db.sock" # DB_NB_PID="/usr/local/etc/openvswitch/ovnnb_db.pid" # DB_SB_SOCK="usr/local/etc/openvswitch/sb_db.sock" # DB_SB_PID="/usr/local/etc/openvswitch/ovnsb_db.pid" # ...
Configure the Networking server component. The Networking service implements OVN as an ML2 driver. Edit the
/etc/neutron/neutron.conffile:Enable the ML2 core plug-in.
[DEFAULT] ... core_plugin = neutron.plugins.ml2.plugin.Ml2Plugin
If the QoS service is enabled then you also need to enable the OVN QoS notification driver.
[qos] ... notification_drivers = ovn-qos
(Optional) Enable the native or conventional layer-3 service.
[DEFAULT] ... service_plugins = L3_SERVICE
Configure the ML2 plug-in. Edit the
/etc/neutron/plugins/ml2/ml2_conf.inifile:Configure the OVN mechanism driver, network type drivers, self-service (tenant) network types, and enable the port security extension.
[ml2] ... mechanism_drivers = ovn type_drivers = local,flat,vlan,geneve tenant_network_types = geneve extension_drivers = port_security overlay_ip_version = 4
Note
To enable VLAN self-service networks, add
vlanto thetenant_network_typesoption. The first network type in the list becomes the default self-service network type.To use IPv6 for all overlay (tunnel) network endpoints, set the
overlay_ip_versionoption to6.Configure the Geneve ID range and maximum header size. The IP version overhead (20 bytes for IPv4 (default) or 40 bytes for IPv6) is added to the maximum header size based on the ML2
overlay_ip_versionoption.[ml2_type_geneve] ... vni_ranges = 1:65536 max_header_size = 38
Note
The Networking service uses the
vni_rangesoption to allocate network segments. However, OVN ignores the actual values. Thus, the ID range only determines the quantity of Geneve networks in the environment. For example, a range of5001:6000defines a maximum of 1000 Geneve networks.Optionally, enable support for VLAN provider and self-service networks on one or more physical networks. If you specify only the physical network, only administrative (privileged) users can manage VLAN networks. Additionally specifying a VLAN ID range for a physical network enables regular (non-privileged) users to manage VLAN networks. The Networking service allocates the VLAN ID for each self-service network using the VLAN ID range for the physical network.
[ml2_type_vlan] ... network_vlan_ranges = PHYSICAL_NETWORK:MIN_VLAN_ID:MAX_VLAN_ID
Replace
PHYSICAL_NETWORKwith the physical network name and optionally define the minimum and maximum VLAN IDs. Use a comma to separate each physical network.For example, to enable support for administrative VLAN networks on the
physnet1network and self-service VLAN networks on thephysnet2network using VLAN IDs 1001 to 2000:network_vlan_ranges = physnet1,physnet2:1001:2000
Enable security groups.
[securitygroup] ... enable_security_group = true
Note
The
firewall_driveroption under[securitygroup]is ignored since the OVN ML2 driver itself handles security groups.Configure OVS database access, OVN L3 mode, L3 scheduler, L3 admin net CIDR and OVN DHCP mode
[ovn] ... ovn_nb_connection = tcp:IP_ADDRESS:6641 ovn_sb_connection = tcp:IP_ADDRESS:6642 ovn_l3_mode = OVN_L3_MODE ovn_l3_scheduler = OVN_L3_SCHEDULER ovn_l3_admin_net_cidr = OVN_L3_ADMIN_NET_CIDR ovn_native_dhcp = OVN_NATIVE_DHCP
Note
Replace
IP_ADDRESSwith the IP address of the controller node that runs theovsdb-serverservice. ReplaceOVN_L3_MODEwithTrueif you enabled the native layer-3 service in/etc/neutron/neutron.confelseFalse. The ovn_l3_scheduler value is only valid if ovn_l3_mode is set toTrue. ReplaceOVN_L3_SCHEDULERwithleastloadedif you want the scheduler to select a compute node with the least number of gateway routers orchanceif you want the scheduler to randomly select a compute node from the available list of compute nodes. The ovn_l3_admin_net_cidr value is only valid if ovn_l3_mode is set toTrue. The deafult value forOVN_L3_ADMIN_NET_CIDRis169.254.128.0/30, if you want to use a diferent cidr replaceOVN_L3_ADMIN_NET_CIDRto a new cidr. And finally, replaceOVN_NATIVE_DHCPwithTrueif you want to enable the native DHCP service elseFalseto use the conventional DHCP agent.
Start the
neutron-serverservice.
Network nodes¶
Deployments using OVN native layer-3 and DHCP services do not require conventional network nodes because connectivity to external networks (including VTEP gateways) and routing occurs on compute nodes. OVN currently relies on the conventional metadata agent that typically operates on network nodes. However, you can deploy this agent on controller or compute nodes.
Compute nodes¶
Each compute node runs the OVS and ovn-controller services. The
ovn-controller service replaces the conventional OVS layer-2 agent.
Install the
openvswitch-ovnandnetworking-ovnpackages.Start the OVS service.
Using the systemd unit:
# systemctl start openvswitchUsing the
ovs-ctlscript:# /usr/share/openvswitch/scripts/ovs-ctl start --system-id="random"
Configure the OVS service.
Use OVS databases on the controller node.
# ovs-vsctl set open . external-ids:ovn-remote=tcp:IP_ADDRESS:6642
Replace
IP_ADDRESSwith the IP address of the controller node that runs theovsdb-serverservice.Enable one or more overlay network protocols. At a minimum, OVN requires enabling the
geneveprotocol. Deployments using VTEP gateways should also enable thevxlanprotocol.# ovs-vsctl set open . external-ids:ovn-encap-type=geneve,vxlan
Note
Deployments without VTEP gateways can safely enable both protocols.
Note
Overlay network protocols generally require reducing MTU on VM interfaces to account for additional packet overhead. See the DHCP agent configuration in the Installation Guide for more information.
Configure the overlay network local endpoint IP address.
# ovs-vsctl set open . external-ids:ovn-encap-ip=IP_ADDRESS
Replace
IP_ADDRESSwith the IP address of the overlay network interface on the compute node.
Start the
ovn-controllerservice.Using the systemd unit:
# systemctl start ovn-controllerUsing the
ovn-ctlscript:# /usr/share/openvswitch/scripts/ovn-ctl start_controller
Verify operation¶
Each compute node should contain an
ovn-controllerinstance.# ovn-sbctl show <output>