Comment 10 for bug 1736022

According to this:
http://www.microhowto.info/howto/configure_an_ethernet_interface_as_a_vlan_trunk_on_debian.html

It seems to say that maybe there was a problem finding the underlying device.
I wonder if the issue is that the underlying enp4s0f0 is left "unconfigured"?

The other thing you could potentially do is try to create a bridge in MAAS, which should then already be configured by the time Juju comes along, which should mean that Juju uses whatever bridge you've already declared.

The main reason that Juju doesn't pre-configure MAAS machines is because
a) I'm not sure if configuring it ahead of time means that MAAS would then forever think you want exactly those bridges on that machine. Meaning if you then release the machine, and later wanted to use it for a different purpose, you would still end up with the bridges. People have very specifically asked for us to only bridge the interfaces that expressly need them. So if a given machine doesn't run any containers, then they don't want any bridges on that machine.
b) You can always ask after provisioning the base machine to then add a container at any point. Which means Juju already needed all the logic to handle someone asking for a container 2-months after deploying the original machine. Better to use that code path regularly.

However, Juju *does* use bridges that already exist, so if you have a reason that you don't want to wait for dynamic bridging, and you know how the machines will be used, you can go craft that in MAAS and Juju will just use those settings that were already defined.