LXD Private-Public Network

Creating a Private-Public Network with LXD using Cloud-init

With this method, a private network provides an IP that can be used by another device on the same network, such as 192.168.0.122, while a public network provides an IP that can be used by the same device hosting the container, such as 10.0.1.122. Note that this method has not been tested on wifi.

To create a "ppnet" profile for private-public networking, you will need to know the name of your network interface. You can find this information by running the following command in a terminal:
ip route show default

This will display output similar to:
default via 192.168.0.1 dev enp0s25 proto dhcp metric 100

In this example, the network interface is "enp0s25".

To create a copy of the "default" profile and rename it to "ppnet", run the following command:
lxc profile copy default ppnet

Then, view the newly created "ppnet" profile using the following command:
lxc profile show ppnet

To configure the "ppnet" profile, edit it using the following command:
lxc profile edit ppnet

This will open a text editor where you can modify the profile's configuration. Replace the existing configuration with the following:

config:
  user.network-config: |
    version: 1
    config:
      - type: physical
        name: eth0
        subnets:
          - type: dhcp
            ipv4: true
      - type: physical
        name: eth1
        subnets:
          - type: dhcp
            ipv4: true
description: Default LXD profile
devices:
  eth0:
    name: eth0
    parent: lxdbr0
    type: nic
  eth1:
    name: eth1
    nictype: macvlan
    parent: enp0s25
    type: nic
  root:
    path: /
    pool: default
    type: disk
name: ppnet
used_by:

Note that you should replace "enp0s25" with the name of your network interface, and adjust the subnets as needed.

Finally, launch a new container with the "ppnet" profile using the following command:
lxc launch ubuntu:20.04 gitea2 --profile ppnet

References

https://blog.simos.info/how-to-add-both-a-private-and-public-network-to-lxd-using-cloud-init/