Add env.d extra configuration directory to etc/openstack_deploy/

Like etc/openstack_deploy/conf.d/ we need a way to add additional
containers to the infrastructure without modifying the provided
openstack_environment.yml file.  This patch looks for an env.d
directory and merges their configurations into the inventory. An
example extra_container configuration file is also provided.

Closes-bug: 1440117

Change-Id: Ibc83770e69efb67996a012c96766b4a88774986e

etc/openstack_deploy/env.d/extra_container.yml.example

@@ -0,0 +1,44 @@
+---
+# Copyright 2014, Rackspace US, Inc.
+# #
+# # 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.
+
+component_skel:
+  example_api:
+    belongs_to:
+      # This is a meta group of a given component type.
+      - example_all
+
+container_skel:
+  example_api_container:
+    belongs_to:
+      # This is a group of containers mapped to a physical host.
+      - example-infra_containers
+    contains:
+      # This maps back to an item in the component_skel.
+      - example_api
+    properties:
+      # These are arbitrary key value pairs.
+      service_name: example_service
+      # This is the image that the lxc container will be built from.
+      container_release: trusty
+
+physical_skel:
+  # This maps back to items in the container_skel.
+  example-infra_containers:
+    belongs_to:
+      - all_containers
+  # This is a required pair for the container physical entry.
+  example-infra_hosts:
+    belongs_to:
+      - hosts

playbooks/inventory/dynamic_inventory.py

@@ -556,7 +556,7 @@ def _add_additional_networks(key, inventory, ip_q, q_name, netmask, interface,
         if properties:
             is_metal = properties.get('is_metal', False)
 
-        ## This should convert found addresses based on q_name + "_address"
+        # This should convert found addresses based on q_name + "_address"
         #  and then build the network if its not found.
         if not is_metal and old_address not in networks:
             network = networks[old_address] = network_entry()
@@ -857,7 +857,7 @@ def _merge_dict(base_items, new_items):
 
 
 def _extra_config(user_defined_config, base_dir):
-    """Discover new items in a conf.d directory and add the new values.
+    """Discover new items in any extra directories and add the new values.
 
     :param user_defined_config: ``dict``
     :param base_dir: ``str``
@@ -920,6 +920,11 @@ def main():
             % (env_version, version)
         )
 
+    # Load anything in an env.d directory if found
+    env_plugins = os.path.join(local_path, 'env.d')
+    if os.path.isdir(env_plugins):
+        _extra_config(user_defined_config=environment, base_dir=env_plugins)
+
     # Load existing inventory file if found
     dynamic_inventory_file = os.path.join(
         local_path, 'openstack_inventory.json'