Public IPs output value must not be empty when deployment completed.

[denismakogon]

In all scenarios, the output variable public_ip for an instance (or a pool) remains empty when the compute instance is deployed successfully.
Here's an example. For the deployment of 3 instances w/ public IPs the output value is:

ip_address = [
  "",
  "",
  "",
]

after some time it will be updated to the exact value. However, it makes the full deployment that uses this module divided onto two stages:

1. Deploy VMs and keep refreshing until you get the IPs.
2. Proceed with the rest of the deployment.