Rename zones table to cells and Instance.zone_name to cell_name

Vish made an executive decision to use the term 'Cell' to refer to the
former 'Zone'.  :)  This fixes up the core code required for the future
Cells branch.

Change-Id: Iff0fb01f0c2862a646bfb2d3fd4e218f1d2b7a93

5 files changed, 78 insertions, 43 deletions

diff --git a/nova/db/api.py b/nova/db/api.py
index cba0e7456e..bf94747df0 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -1448,29 +1448,29 @@ def instance_type_destroy(context, name):
 ####################
 
 
-def zone_create(context, values):
-    """Create a new child Zone entry."""
-    return IMPL.zone_create(context, values)
+def cell_create(context, values):
+    """Create a new child Cell entry."""
+    return IMPL.cell_create(context, values)
 
 
-def zone_update(context, zone_id, values):
-    """Update a child Zone entry."""
-    return IMPL.zone_update(context, zone_id, values)
+def cell_update(context, cell_id, values):
+    """Update a child Cell entry."""
+    return IMPL.cell_update(context, cell_id, values)
 
 
-def zone_delete(context, zone_id):
-    """Delete a child Zone."""
-    return IMPL.zone_delete(context, zone_id)
+def cell_delete(context, cell_id):
+    """Delete a child Cell."""
+    return IMPL.cell_delete(context, cell_id)
 
 
-def zone_get(context, zone_id):
-    """Get a specific child Zone."""
-    return IMPL.zone_get(context, zone_id)
+def cell_get(context, cell_id):
+    """Get a specific child Cell."""
+    return IMPL.cell_get(context, cell_id)
 
 
-def zone_get_all(context):
-    """Get all child Zones."""
-    return IMPL.zone_get_all(context)
+def cell_get_all(context):
+    """Get all child Cells."""
+    return IMPL.cell_get_all(context)
 
 
 ####################
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 6496ab7b99..ba3c12b41e 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -3539,47 +3539,47 @@ def instance_type_destroy(context, name):
 
 
 @require_admin_context
-def zone_create(context, values):
-    zone = models.Zone()
-    zone.update(values)
-    zone.save()
-    return zone
+def cell_create(context, values):
+    cell = models.Cell()
+    cell.update(values)
+    cell.save()
+    return cell
 
 
-def _zone_get_by_id_query(context, zone_id, session=None):
-    return model_query(context, models.Zone, session=session).\
-                       filter_by(id=zone_id)
+def _cell_get_by_id_query(context, cell_id, session=None):
+    return model_query(context, models.Cell, session=session).\
+                       filter_by(id=cell_id)
 
 
 @require_admin_context
-def zone_update(context, zone_id, values):
-    zone = zone_get(context, zone_id)
-    zone.update(values)
-    zone.save()
-    return zone
+def cell_update(context, cell_id, values):
+    cell = cell_get(context, cell_id)
+    cell.update(values)
+    cell.save()
+    return cell
 
 
 @require_admin_context
-def zone_delete(context, zone_id):
+def cell_delete(context, cell_id):
     session = get_session()
     with session.begin():
-        _zone_get_by_id_query(context, zone_id, session=session).\
+        _cell_get_by_id_query(context, cell_id, session=session).\
                 delete()
 
 
 @require_admin_context
-def zone_get(context, zone_id):
-    result = _zone_get_by_id_query(context, zone_id).first()
+def cell_get(context, cell_id):
+    result = _cell_get_by_id_query(context, cell_id).first()
 
     if not result:
-        raise exception.ZoneNotFound(zone_id=zone_id)
+        raise exception.CellNotFound(cell_id=cell_id)
 
     return result
 
 
 @require_admin_context
-def zone_get_all(context):
-    return model_query(context, models.Zone, read_deleted="no").all()
+def cell_get_all(context):
+    return model_query(context, models.Cell, read_deleted="no").all()
 
 
 ####################
diff --git a/nova/db/sqlalchemy/migrate_repo/versions/082_zone_to_cell.py b/nova/db/sqlalchemy/migrate_repo/versions/082_zone_to_cell.py
new file mode 100644
index 0000000000..79e99503af
--- /dev/null
+++ b/nova/db/sqlalchemy/migrate_repo/versions/082_zone_to_cell.py
@@ -0,0 +1,35 @@
+# Copyright 2012 OpenStack LLC.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from sqlalchemy import MetaData, Table
+
+
+def upgrade(migrate_engine):
+    meta = MetaData()
+    meta.bind = migrate_engine
+    instances = Table('instances', meta, autoload=True)
+    zone_name = instances.c.zone_name
+    zone_name.alter(name='cell_name')
+    zones = Table('zones', meta, autoload=True)
+    zones.rename('cells')
+
+
+def downgrade(migrate_engine):
+    meta = MetaData()
+    meta.bind = migrate_engine
+    instances = Table('instances', meta, autoload=True)
+    cell_name = instances.c.cell_name
+    cell_name.alter(name='zone_name')
+    cells = Table('cells', meta, autoload=True)
+    cells.rename('zones')
diff --git a/nova/db/sqlalchemy/models.py b/nova/db/sqlalchemy/models.py
index 7f70a5d556..b15cece8d2 100644
--- a/nova/db/sqlalchemy/models.py
+++ b/nova/db/sqlalchemy/models.py
@@ -278,8 +278,8 @@ class Instance(BASE, NovaBase):
     # EC2 disable_api_termination
     disable_terminate = Column(Boolean(), default=False, nullable=False)
 
-    # Openstack zone name
-    zone_name = Column(String(255))
+    # Openstack compute cell name
+    cell_name = Column(String(255))
 
 
 class InstanceInfoCache(BASE, NovaBase):
@@ -870,9 +870,9 @@ class InstanceTypeExtraSpecs(BASE, NovaBase):
                  'InstanceTypeExtraSpecs.deleted == False)')
 
 
-class Zone(BASE, NovaBase):
-    """Represents a child zone of this zone."""
-    __tablename__ = 'zones'
+class Cell(BASE, NovaBase):
+    """Represents parent and child cells of this cell."""
+    __tablename__ = 'cells'
     id = Column(Integer, primary_key=True)
     name = Column(String(255))
     api_url = Column(String(255))
diff --git a/nova/exception.py b/nova/exception.py
index e1caf28fe9..4de0f65d1b 100644
--- a/nova/exception.py
+++ b/nova/exception.py
@@ -748,8 +748,8 @@ class FlavorNotFound(NotFound):
     message = _("Flavor %(flavor_id)s could not be found.")
 
 
-class ZoneNotFound(NotFound):
-    message = _("Zone %(zone_id)s could not be found.")
+class CellNotFound(NotFound):
+    message = _("Cell %(cell_id)s could not be found.")
 
 
 class SchedulerHostFilterNotFound(NotFound):
@@ -1006,4 +1006,4 @@ class InstanceNotFound(NotFound):
 
 
 class InvalidInstanceIDMalformed(Invalid):
-        message = _("Invalid id: %(val) (expecting \"i-...\").")
+    message = _("Invalid id: %(val) (expecting \"i-...\").")