Make port publishing easier

[larsks]

Port forwarding is a nice way to expose services, but the process is too complicated. Let's say that I want to "forward tcp port 4321 from a public ip address to port 4321 on internal address 10.100.100.10". That means:

1. Find the existing port with 10.100.100.10, or create a new port with that address if one doesn't already exist.
2. Create a floating ip address.
3. Take the information from the first two steps and plug it into an openstack floating ip publishing command

It would be really neat if instead I could write:

openstack esi publish --network mynetwork --from 10.100.100.10:4321

And have it perform all the above steps. If I want to use a specific floating ip:

openstack esi publish --network mynetwork --from 10.100.100.10:4321 --to 128.31.20.112

And if I want the external port to be different from the internal port:

openstack esi publish --network mynetwork --from 10.100.100.10:4321 --to 128.31.20.112:1234

(I've gone with the verb publish here, because that's what we use in the container world, but we could just as easily use something like port forward)

[larsks]

There should probably be a corresponding unpublish verb that would delete the port forwarding, and maybe optionally delete the internal port and the floating ip if there are no other port forwardings associated with it. Maybe that's something like:

openstack esi unpublish --purge --from 10.100.100.10:4321

[tzumainn]

Fair enough. I'd probably go for the "port forwarding" syntax just because it matches existing OpenStack commands better.

[larsks]

E.g. see the portforward.sh script here.