feat: add 'netbox_ip_address_assignment' resource (#601)

[skoppe]

Adds netbox_ip_address_assignment resource which:

Assigns a NetBox Device, physical or virtual, to an already constructed IP address.

In cases where the device assigned to the IP Address is not yet known when constructing the IP address (using either netbox_available_ip_address or netbox_ip_address), this resource allows assigning it afterwards.

A typical scenario is when you statically allocate IP's to virtual machines and use netbox_available_ip_address to fetch that IP, but where the netbox_virtual_machine or netbox_interface can only be constructed after having started the virtual machine.`

No idea on the docs, the makefile produces garbage.

[fbreckle]

Doesn't this resource introduce drift in the initial netbox_available_ip_address resource?

[skoppe]

Doesn't this resource introduce drift in the initial netbox_available_ip_address resource?

I expected so myself as well, but for some reason it doesn't. I ran it against a staging environment with plenty of other resources and saw no drift.

I'll spend some time thinking it through. In the meantime, is something else missing here, or is this good to go?

[skoppe]

Ah, alas, if I set some additional field on the original netbox_ip_address and apply again it overwrites any assignment set via netbox_ip_address_assigment.

Bummer. This is a bit unfortunate since the netbox api does allow updating entities partially but somehow that capability isn't available in the go api.

[skoppe]

As mentioned in #613

This PR has one issue left to tackle: any assignment can be left undone after changes to either ip resource.

What needs to be done is to add an external_assignment boolean to both ip resources, so it knows to avoid updating/clearing any assignment.

[skoppe]

@fbreckle please review again. I have added a external_assignment boolean to the netbox_ip_address and netbox_available_ip_address resource to avoid conflicts with netbox_ip_address_assignment.

[MiBUl-eu]

Are there any news on that MR?

@skoppe can you rebase your branch with the master branch?

[skoppe]

Are there any news on that MR?

@skoppe can you rebase your branch with the master branch?

Sure, let me do later today.