integration-test failure: netplan 0.106 lunar++ test_ovs_member_interfaces_not_excluded

[blackboxsw]

Bug report

Jenkins tests are failing on cloud-init 23.1.2 on lxd_vm due to defaults for networking setup not including setting ipv4 default routes.
This does not affect kinetic and newer. this is likely an integration test issue and also affects tip of main branch.

Steps to reproduce the problem

CLOUD_INIT_OS_IMAGE=lunar CLOUD_INIT_PLATFORM=lxd_vm CLOUD_INIT_KEEP_INSTANCE=1 tox -e integration-tests tests/integration_tests/bugs/test_lp1898997.py::TestInterfaceListingWithOpenvSwitch::test_ovs_member_interfaces_not_excluded

Jenkins errors:

=================================== FAILURES ===================================
_ TestInterfaceListingWithOpenvSwitch.test_ovs_member_interfaces_not_excluded __

self = <test_lp1898997.TestInterfaceListingWithOpenvSwitch object at 0x7f277fd01690>
client = <tests.integration_tests.instances.IntegrationInstance object at 0x7f277feb6c10>

    def test_ovs_member_interfaces_not_excluded(self, client):
        # We need to install openvswitch for our provided network configuration
        # to apply (on next boot), so DHCP on our default interface to fetch it
        client.execute("dhclient enp5s0")
        client.execute("apt update -qqy")
        client.execute("apt-get install -qqy openvswitch-switch")
    
        # Now our networking config should successfully apply on a clean reboot
        client.execute("cloud-init clean --logs")
        client.restart()
    
        cloudinit_output = client.read_from_file("/var/log/cloud-init.log")
    
        # Confirm that the network configuration was applied successfully
        verify_clean_log(cloudinit_output)
        # Confirm that the applied network config created the OVS bridge
        assert "ovs-br" in client.execute("ip addr")
    
        # Test that we can ping our gateway using our bridge
        gateway = client.execute(
            "ip -4 route show default | awk '{ print $3 }'"
        )
        ping_result = client.execute(
            "ping -c 1 -W 1 -I ovs-br {}".format(gateway)
        )
>       assert ping_result.ok
E       AssertionError: assert False
E        +  where False = ''.ok

tests/integration_tests/bugs/test_lp1898997.py:83: AssertionError

The response from ip -4 route show default on the Kinetic vs Lunar launched lxd_vm shows empty:

csmith@midtown:~/src/cloud-init$ lxc exec cloudinit-0713-1633173mkmg57i -- ip -4 route show default
default via 10.125.221.1 dev ovs-br proto dhcp src 10.125.221.61 metric 100 
csmith@midtown:~/src/cloud-init$ lxc exec cloudinit-0713-162959yk74h2oh -- ip -4 route show default

Environment details

• Cloud-init version: 23.1.2
• Operating System Distribution: Ubuntu Lunar
• Cloud provider, platform or installer type: lxd_vm

cloud-init logs

No failures warnings or traces in cloud-init logs seen
cloud-init.log.txt