* provider/openstack: Add all_fixed_ips computed attribute to port resource
This commit adds the `all_fixed_ips` attribute to the
openstack_networking_port_v2 resource. This contains all of the port's
Fixed IPs returned by the Networking v2 API.
* provider/openstack: Revert Port fixed_ip back to a List
This commit reverts the changes made in a8c4e81a6e3f2. This
re-enables the ability to reference IP addresses using the
numerical-element notation.
This commit also makes fixed_ip a non-computed field, meaning
Terraform will no longer set fixed_ip with what was returned
by the API. This resolves the original issue about ordering.
The last use-case is for fixed_ips that received an IP address
via DHCP. Because fixed_ip is no longer computed, the DHCP IP
will not be set. The workaround for this use-case is to use the
new all_fixed_ips attribute.
In effect, users should use fixed_ip only as a way of inputting
data into Terraform and use all_fixed_ips as the output returned
by the API. If use-cases exist where fixed_ip can be used as an
output, that's a bonus feature.