Currently the network interfaces are auto-detected at container/POD launch. This does not allow use cases like docker network connect, where network interfaces can be dynamically added to the container.
This is currently the only way to support multiple network interfaces with a docker container (outside of swarm).

Also firewall rules and routes may be added to the container post creation.

Note: The runtime is a passive component. Hence hotplug needs to be implemented by an active component running in the network namespace of the container/POD.

To implement network hotplug support

• Post network auto detection the shim needs to monitor the namespace for changes to the network setup.
  This includes
  - interface creation/configuration
  - route add/delete
  - firewall rules setup
• QEMU supports QMP based device hotplug
• The (hyperstart) agent inside the VM will need to receive the updated configuration
  - Hence the shim will need a interface into the CC proxy to send updated configuration
  Note: This is different from today where all setup is through the runtime -> proxy -> hyperstart

The first step in this implementation would be to not implement dynamic network hotplug, but to perform all device attaches to QEMU via QMP. This will allow for the hotplug of any device in the future.