lxd container: port forwarding like docker
One of the developers wrote in this issue about the topic:
This has been closed, but to give a clear answer: lxd (at least as currently intended) will not do host networking. So in general you would port-forward to a web-server in a lxd container the same way you would do with lxc - you can pass in a nic from the host into the container and have your local router provide it its own address; or use route-based networking to container veths; or use iptables forwarding to forward host traffic into the container (which is what I usually do).
See https://help.ubuntu.com/lts/serverguide/lxc.html#lxc-network for more information.
So, I'm afraid, as things stand currently, there is no port forwarding, neither now nor in the future.
Four years later, the prediction given in this answer was fortunately too pesimisitc. Port forwarding has been implementented in LXD in the meantime as is documented here.
To forward port 80 on the host to 8080 in the container, simply do
lxc config device add jitsi port1 proxy listen=tcp:<hostip>:80 connect=tcp:<ontainerip>:8080