Allow creating isolated OVN networks (no uplink)

[SpiffyEight77]

Description

• feat: allow creating isolated OVN networks (no uplink)
• close Allow creating isolated OVN networks (no uplink) #936

Details

• OS: Ubuntu 24.04
• Arch: x86_64

Test result

root@playground:~/incus# incus network create ovn-none --type ovn network=none --debug
Network ovn-none created

root@playground:~/incus# incus network list
+------------+----------+---------+-----------------+---------------------------+-------------+---------+---------+
|    NAME    |   TYPE   | MANAGED |      IPV4       |           IPV6            | DESCRIPTION | USED BY |  STATE  |
+------------+----------+---------+-----------------+---------------------------+-------------+---------+---------+
| br-int     | bridge   | false   |                 |                           |             | 0       |         |
+------------+----------+---------+-----------------+---------------------------+-------------+---------+---------+
| enp1s0     | physical | false   |                 |                           |             | 0       |         |
+------------+----------+---------+-----------------+---------------------------+-------------+---------+---------+
| incusbr0   | bridge   | true    | 10.216.127.1/24 | fd42:fa48:9935:6601::1/64 |             | 1       | CREATED |
+------------+----------+---------+-----------------+---------------------------+-------------+---------+---------+
| lo         | loopback | false   |                 |                           |             | 0       |         |
+------------+----------+---------+-----------------+---------------------------+-------------+---------+---------+
| lxcbr0     | bridge   | false   |                 |                           |             | 0       |         |
+------------+----------+---------+-----------------+---------------------------+-------------+---------+---------+
| ovn-none   | ovn      | true    | 10.94.120.1/24  | fd42:d331:623f:c870::1/64 |             | 0       | CREATED |
+------------+----------+---------+-----------------+---------------------------+-------------+---------+---------+
| ovs-system | unknown  | false   |                 |                           |             | 0       |         |
+------------+----------+---------+-----------------+---------------------------+-------------+---------+---------+

[stgraber]

Thanks, I'm going to pull that one and take a look, see if I can get it over the finish line.

[stgraber]

Did a quick rebase on current main branch.

[stgraber]

So far I just did some basic rebasing and renaming of commits.

Next once I'm back on my desktop I'll push that logic to a test cluster so I can see what's going on with the addressing side of things and validate the rest of the logic.

Hopefully there isn't too much to it and I can sneak that one in just before tagging 6.4 :)

[stgraber]

Got it working. I managed to simplify a bit of the logic you had, I then had to add a bit more logic to handle the initial setup of the network which was failing and had to tweak the DHCPv4, DHCPv6 and RA code paths to just skip the DNS part. That was the issue you had with lacking DHCP.

I also had to add a bit of logic to the nic device to skip the uplink if it's "none" and lastly tweak the deletion logic so it doesn't fail due to missing router ports.

[stgraber]

Just waiting for doc and static analysis tests to complete, the rest isn't relevant as OVN tests happen separately through CI.