Juju attempts to add incorrect OpenStack subnet

[Joseph Phillips]

Succinctly illustrated by this example on Canonistack:

$ juju subnets
subnets:
  10.6.0.0/24:
    type: ipv4
    provider-id: 365c43b9-5156-42ef-ab88-994ccfbb7b4c
    provider-network-id: 4f6733c0-1bea-4da1-99aa-cdc487758a81
    status: in-use
    space: alpha
    zones:
    - nova
  10.48.128.0/17:
    type: ipv4
    provider-id: 0915bb73-94b6-493d-af18-2aa9a21fc415
    provider-network-id: d75416f2-093a-4ffb-aaf6-d22f350d01ea
    status: in-use
    space: alpha
    zones:
    - nova
  252.0.0.0/8:
    type: ipv4
    provider-id: 0915bb73-94b6-493d-af18-2aa9a21fc415-INFAN-10-48-128-0-17
    provider-network-id: d75416f2-093a-4ffb-aaf6-d22f350d01ea
    status: in-use
    space: alpha
    zones:
    - nova
$ juju add-space beta 10.48.120.0/17
ERROR cannot add space "beta": subnet "10.48.0.0/17" not found

The CIDR is being mangled in-flight.

[Joseph Phillips (manadart)]

This is due to CIDR parsing.

We parse the input into its correct CIDR, but discovered subnets are stored verbatim as how they are listed in OpenStack, so no match is found.