Comment 2 for bug 1819171

Pasting a redacted version below

Manual provisioning
$ juju add-machine --constraints "tags=infra,spaces=space-oam,space-ext" ssh:ubuntu@10.0.0.4

$ juju spaces
Space Subnets
space-ext 10.0.0.0/24
space-oam 10.1.0.0/24

$ juju show-machine 0
model: openstack
machines:
  "0":
    juju-status:
      current: started
      since: 08 Mar 2019 11:58:28+01:00
      version: 2.5.1
    dns-name: 10.0.0.4
    ip-addresses:
    - 10.0.0.4
    - 10.1.0.130
    instance-id: manual:10.0.0.4
    machine-status:
      current: running
      message: Manually provisioned machine
      since: 08 Mar 2019 11:58:18+01:00
    series: xenial
    network-interfaces:
      br-ext:
        ip-addresses:
        - 10.1.0.130
        mac-address: xx:xx:xx
        gateway: 10.1.0.129
        space: space-ext
        is-up: true
      br-oam:
        ip-addresses:
        - 10.0.0.4
        mac-address: xx:xx:xx
        space: space-oam
        is-up: true
      lxdbr0:
        ip-addresses:
        - 10.0.88.1
        mac-address: yy:yy:yy
        is-up: true
    hardware: arch=amd64 ...

Test container:

$ juju deploy ubuntu --to lxd:0 --constraints spaces=space-oam,space-ext --bind space-oam --series=xenial