Refactoring inventory generation data manipulation

Segmenting out changes to the inventory generation script which are
related to datastructure manipulations in preparation for segmenting
out storage-related operations.

Change-Id: I3160862b4fea92bce4c951107e154fd3ddc21234

lib/dictutils.py

@@ -17,12 +17,44 @@
 #
 
 
+def merge_dict(base_items, new_items):
+    """Recursively merge new_items into some base_items.
+
+    If an empty dictionary is provided as a new value, it will
+    completely replace the existing dictionary.
+
+    :param base_items: ``dict``
+    :param new_items: ``dict``
+    :return dictionary:
+    """
+    for key, value in new_items.iteritems():
+        if isinstance(value, dict) and value:
+            base_merge = merge_dict(base_items.get(key, {}), value)
+            base_items[key] = base_merge
+        else:
+            base_items[key] = new_items[key]
+    return base_items
+
+
+def append_if(array, item):
+    """Append an ``item`` to an ``array`` if its not already in it.
+
+    :param array: ``list``  List object to append to
+    :param item: ``object``  Object to append to the list
+    :returns bool:  Flag indicating whether the append happend (True)
+        or not (False)
+    """
+    if item not in array:
+        array.append(item)
+        return True
+    return False
+
+
 def recursive_list_removal(inventory, purge_list):
     """Remove items from a list.
 
-    Keyword arguments:
+    :param inventory: ``dict`` Dictionary representing the inventory
-    inventory -- inventory dictionary
+    :param purge_list: ``list`` List of items to remove
-    purge_list -- list of items to remove
     """
     for item in purge_list:
         for _item in inventory:
@@ -34,8 +66,8 @@ def recursive_dict_removal(inventory, purge_list):
     """Remove items from a dictionary.
 
     Keyword arguments:
-    inventory -- inventory dictionary
+    :param inventory: ``dict`` Dictionary representing the inventory
-    purge_list -- list of items to remove
+    :param purge_list: ``list`` List of items to remove
     """
     for key, value in inventory.iteritems():
         if isinstance(value, dict):

lib/generate.py

@@ -28,6 +28,9 @@ import uuid
 import warnings
 import yaml
 
+from dictutils import append_if
+from dictutils import merge_dict
+
 logger = logging.getLogger('osa-inventory')
 
 USED_IPS = set()
@@ -901,39 +904,6 @@ def _parse_global_variables(user_cidr, inventory, user_defined_config):
                     del inventory['all']['vars'][key]
 
 
-def append_if(array, item):
-    """Append an ``item`` to an ``array`` if its not already in it.
-
-    :param array: ``list``  List object to append to
-    :param item: ``object``  Object to append to the list
-    :returns bool:  Flag indicating whether the append happend (True)
-        or not (False)
-    """
-    if item not in array:
-        array.append(item)
-        return True
-    return False
-
-
-def _merge_dict(base_items, new_items):
-    """Recursively merge new_items into some base_items.
-
-    If an empty dictionary is provided as a new value, it will
-    completely replace the existing dictionary.
-
-    :param base_items: ``dict``
-    :param new_items: ``dict``
-    :return dictionary:
-    """
-    for key, value in new_items.iteritems():
-        if isinstance(value, dict) and value:
-            base_merge = _merge_dict(base_items.get(key, {}), value)
-            base_items[key] = base_merge
-        else:
-            base_items[key] = new_items[key]
-    return base_items
-
-
 def _extra_config(user_defined_config, base_dir):
     """Discover new items in any extra directories and add the new values.
 
@@ -944,7 +914,7 @@ def _extra_config(user_defined_config, base_dir):
         for name in files:
             if name.endswith(('.yml', '.yaml')):
                 with open(os.path.join(root_dir, name), 'rb') as f:
-                    _merge_dict(
+                    merge_dict(
                         user_defined_config,
                         yaml.safe_load(f.read()) or {}
                     )