Move get_server_ip into tempest.common.compute

This will be required by the new wait_until={PINGABLE|SSHABLE} logic
within the module so move this down from
tempest.api.compute.base.BaseV2ComputeTest.

A version of this is also present in tempest.scenario.manager however
unifying that with this version is left for another change.

Change-Id: Iddfdf48da58320844e265fb1209e25a53d501f93
diff --git a/tempest/api/compute/base.py b/tempest/api/compute/base.py
index ed50282..a110eb4 100644
--- a/tempest/api/compute/base.py
+++ b/tempest/api/compute/base.py
@@ -487,21 +487,8 @@
         :param validation_resources: The dict of validation resources
             provisioned for the server.
         """
-        if CONF.validation.connect_method == 'floating':
-            if validation_resources:
-                return validation_resources['floating_ip']['ip']
-            else:
-                msg = ('When validation.connect_method equals floating, '
-                       'validation_resources cannot be None')
-                raise lib_exc.InvalidParam(invalid_param=msg)
-        elif CONF.validation.connect_method == 'fixed':
-            addresses = server['addresses'][CONF.validation.network_for_ssh]
-            for address in addresses:
-                if address['version'] == CONF.validation.ip_version_for_ssh:
-                    return address['addr']
-            raise exceptions.ServerUnreachable(server_id=server['id'])
-        else:
-            raise lib_exc.InvalidConfiguration()
+        return compute.get_server_ip(
+            server, validation_resources=validation_resources)
 
     @classmethod
     def create_volume(cls, image_ref=None, **kwargs):
diff --git a/tempest/common/compute.py b/tempest/common/compute.py
index 04b67e4..1e59e17 100644
--- a/tempest/common/compute.py
+++ b/tempest/common/compute.py
@@ -25,9 +25,11 @@
 
 from tempest.common import waiters
 from tempest import config
+from tempest import exceptions
 from tempest.lib.common import fixed_network
 from tempest.lib.common import rest_client
 from tempest.lib.common.utils import data_utils
+from tempest.lib import exceptions as lib_exc
 
 CONF = config.CONF
 
@@ -54,6 +56,33 @@
     return False
 
 
+def get_server_ip(server, validation_resources=None):
+    """Get the server fixed or floating IP.
+
+    Based on the configuration we're in, return a correct ip
+    address for validating that a guest is up.
+
+    :param server: The server dict as returned by the API
+    :param validation_resources: The dict of validation resources
+        provisioned for the server.
+    """
+    if CONF.validation.connect_method == 'floating':
+        if validation_resources:
+            return validation_resources['floating_ip']['ip']
+        else:
+            msg = ('When validation.connect_method equals floating, '
+                   'validation_resources cannot be None')
+            raise lib_exc.InvalidParam(invalid_param=msg)
+    elif CONF.validation.connect_method == 'fixed':
+        addresses = server['addresses'][CONF.validation.network_for_ssh]
+        for address in addresses:
+            if address['version'] == CONF.validation.ip_version_for_ssh:
+                return address['addr']
+        raise exceptions.ServerUnreachable(server_id=server['id'])
+    else:
+        raise lib_exc.InvalidConfiguration()
+
+
 def create_test_server(clients, validatable=False, validation_resources=None,
                        tenant_network=None, wait_until=None,
                        volume_backed=False, name=None, flavor=None,