One of the simplest and less memory hungry ways to deploy a tiny networking-ovn all in one it’s still to use packstack.
Note This is an unsupported way of deployment (for the product version), but it must be just fine to give it a try. Afterwards, if you want to get serious and try something closer to production, please have a look af the TripleO deployment guide
On a fresh Centos 7, login and write:
sudo yum install -y "*-queens"
sudo yum update -y
sudo yum install -y openstack-packstack
sudo yum install -y python-setuptools
sudo packstack --allinone \
--cinder-volume-name="aVolume" \
--debug \
--service-workers=2 \
--default-password="packstack" \
--os-aodh-install=n \
--os-ceilometer-install=n \
--os-swift-install=n \
--os-manila-install=n \
--os-horizon-ssl=y \
--amqp-enable-ssl=y \
--glance-backend=file \
--os-neutron-l2-agent=ovn \
--os-neutron-ml2-type-drivers="geneve,flat" \
--os-neutron-ml2-tenant-network-types="geneve" \
--provision-demo=y \
--provision-tempest=y \
--run-tempest=y \
--run-tempest-tests="smoke dashboard"
When that has finished, you will have as root user, a set of keystonerc_admin, and keystonerc_demo files. An example public and private network, a router, and a cirros image.
If you want to see how objects are mapped into OVN, give it a try:
$ sudo ovn-nbctl show
switch 3b31aaa0-eea0-462e-9cdc-866f2bd8171d (neutron-097345d1-3299-43d4-aeda-8af03516b92e) (aka public)
port provnet-097345d1-3299-43d4-aeda-8af03516b92e
type: localnet
addresses: ["unknown"]
port 38eda4cc-4931-4c48-bc83-6e1d72ccb90b
type: router
router-port: lrp-38eda4cc-4931-4c48-bc83-6e1d72ccb90b
switch f6555e37-305f-4342-87f1-f21de5adadc2 (neutron-c3959f48-caa2-4eb9-b217-19e70c2380cb) (aka private)
port ee519f75-08a8-4559-bf44-8acb9b2cec1b
type: router
router-port: lrp-ee519f75-08a8-4559-bf44-8acb9b2cec1b
router 20efb278-0394-4330-a18d-9e40a56b3ae5 (neutron-e70a02f3-6758-4f78-bc50-133b6c6b0584) (aka router1)
port lrp-ee519f75-08a8-4559-bf44-8acb9b2cec1b
mac: "fa:16:3e:f6:c6:d3"
networks: ["10.0.0.1/24"]
port lrp-38eda4cc-4931-4c48-bc83-6e1d72ccb90b
mac: "fa:16:3e:5f:41:cf"
networks: ["172.24.4.7/24"]
gateway chassis: [7a42645d-70b3-4286-8ddc-6240ccdd131c]
nat a5a6bec0-7167-41af-8514-2764502fef21
external ip: "172.24.4.7"
logical ip: "10.0.0.0/24"
type: "snat"