ip link add veth0 type veth peer name veth0_ep
ip link set veth0 up
ip link set veth0_ep up
nmcli device set veth0 managed yes
nmcli device set veth0_ep managed yes
ip link add veth1 type veth peer name veth1_ep
ip link set veth1 up
ip link set veth1_ep up
nmcli device set veth1 managed yes
nmcli device set veth1_ep managed yes

cat << EOF > ovs-bond.yaml
interfaces:
  - name: ovs-br0
    type: ovs-bridge
    state: up
    bridge:
      options:
        stp: false
      port:
        - name: ovs-bond0
          link-aggregation:
            mode: balance-slb
            port:
              - name: veth1
              - name: veth0
EOF

systemctl stop openvswitch
nmstatectl set ovs-bond.yaml || true
echo 'ovs-db: {}' | nmstatectl apply
systemctl start openvswitch

# failed 1
nmstatectl set ovs-bond.yaml

# failed 2
echo '
interfaces:
- name: ovs-br0
  state: absent
- name: veth0
  state: absent
- name: veth1
  state: absent' | nmstatectl apply