--- #
- hosts: localhost
  user: ansible
  connection: local
  become: true
  become_method: sudo
  gather_facts: no

  tasks:
  - name: Stuff
    os_server_facts:
      auth:
        auth_url: http://10.10.10.10:5000/v2.0
        username: admin
        password: password
        project_name: some_Project
      server: worker-4
#    register: openstack_servers

  - debug:
      var: openstack_servers.public_v4



PLAY [localhost] ***************************************************************

TASK [Stuff] *******************************************************************
ok: [localhost]

TASK [debug] *******************************************************************
ok: [localhost] => {
    "openstack_servers.public_v4": "VARIABLE IS NOT DEFINED!"
}

PLAY RECAP *********************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0


===============================================================================================================
===============================================================================================================

--- #
- hosts: localhost
  user: ansible
  connection: local
  become: true
  become_method: sudo
  gather_facts: no

  tasks:
  - name: Stuff
    os_server_facts:
      auth:
        auth_url: http://10.10.10.10:5000/v2.0
        username: admin
        password: password
        project_name: some_project
      server: worker-4
#    register: openstack_servers

  - debug:
      var: openstack_servers
PLAY [localhost] ***************************************************************

TASK [Stuff] *******************************************************************
ok: [localhost]

TASK [debug] *******************************************************************
ok: [localhost] => {
    "openstack_servers": [
        {
            "HUMAN_ID": true,
            "NAME_ATTR": "name",
            "OS-DCF:diskConfig": "MANUAL",
            "OS-EXT-AZ:availability_zone": "nova",
            "OS-EXT-SRV-ATTR:host": "sdmvm2-c02",
            "OS-EXT-SRV-ATTR:hypervisor_hostname": "sdmvm2-c02",
            "OS-EXT-SRV-ATTR:instance_name": "instance-00001e52",
            "OS-EXT-STS:power_state": 1,
            "OS-EXT-STS:task_state": null,
            "OS-EXT-STS:vm_state": "active",
            "OS-SRV-USG:launched_at": "2016-08-12T21:02:32.000000",
            "OS-SRV-USG:terminated_at": null,
            "accessIPv4": "172.0.0.1",
            "accessIPv6": "",
            "addresses": {
                "sdm-devops": [
                    {
                        "OS-EXT-IPS-MAC:mac_addr": "fa:16:3e:5d:dd:49",
                        "OS-EXT-IPS:type": "fixed",
                        "addr": "10.10.10.153",
                        "version": 4
                    },
                    {
                        "OS-EXT-IPS-MAC:mac_addr": "fa:16:3e:5d:dd:49",
                        "OS-EXT-IPS:type": "floating",
                        "addr": "172.0.0.1",
                        "version": 4
                    }
                ]
            },
            "az": "nova",
            "cloud": "defaults",
            "config_drive": "",
            "created": "2016-08-12T21:00:37Z",
            "flavor": {
                "id": "8a6dd25c-1b62-4d94-8bd7-1dd16cb16a51"
            },
            "hostId": "93dd69ee48dd32707dc25055ffea9d3aceae8aa17a3445a3a77e9c5b",
            "human_id": "worker-4",
            "id": "982c4f18-6948-490b-bd09-94c06f3326e6",
            "image": {
                "id": "f2a780d2-6590-4eb0-807b-67011ea694ed"
            },
            "interface_ip": "172.0.0.1",
            "key_name": "ansiblekey",
            "metadata": {},
            "name": "worker-4",
            "networks": {
                "sdm-devops": [
                    "10.10.10.153",
                    "172.0.0.1"
                ]
            },
            "os-extended-volumes:volumes_attached": [],
            "private_v4": "10.10.10.153",
            "progress": 0,
            "public_v4": "172.0.0.1",
            "public_v6": "",
            "region": "",
            "request_ids": [],
            "security_groups": [
                {
                    "name": "default"
                }
            ],
            "status": "ACTIVE",
            "tenant_id": "7ecc557900fa45fd90a34ec362d7c6ab",
            "updated": "2016-09-07T22:06:12Z",
            "user_id": "f2ec51aa4beb450fa3e5d75dd40ce9e8",
            "volumes": [],
            "x_openstack_request_ids": []
        }
    ]
}