From 50eb89ccdcd74c25a0ea93bd9d491cfbe59e4422 Mon Sep 17 00:00:00 2001
From: Stephen Finucane <stephenfin@redhat.com>
Date: Thu, 7 Dec 2023 10:38:28 +0000
Subject: [PATCH] Add wsgi module

This allows deployment tooling to easily switch from passing a binary
path to passing a Python module path. We'll use it shortly.

Change-Id: I7a50ba8ce16184dce3b8a3dec7801155c7a605cd
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>
---
 cinder/wsgi/api.py                            | 24 +++++++++++++++++++
 doc/source/conf.py                            |  4 +++-
 ...d-cinder-wsgi-module-ae72ad42bfebbea8.yaml | 22 +++++++++++++++++
 3 files changed, 49 insertions(+), 1 deletion(-)
 create mode 100644 cinder/wsgi/api.py
 create mode 100644 releasenotes/notes/add-cinder-wsgi-module-ae72ad42bfebbea8.yaml

diff --git a/cinder/wsgi/api.py b/cinder/wsgi/api.py
new file mode 100644
index 00000000000..6adfaaf7202
--- /dev/null
+++ b/cinder/wsgi/api.py
@@ -0,0 +1,24 @@
+# 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.
+
+"""WSGI application entry-point for Cinder Volume API."""
+
+import threading
+
+from cinder.wsgi import wsgi
+
+application = None
+
+lock = threading.Lock()
+with lock:
+    if application is None:
+        application = wsgi.initialize_application()
diff --git a/doc/source/conf.py b/doc/source/conf.py
index a80560e3813..57c2e9814fe 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -64,7 +64,9 @@ apidoc_excluded_paths = [
     'zonemanager/drivers/*',
     'zonemanager/drivers',
     'backup/drivers/*',
-    'backup/drivers']
+    'backup/drivers',
+    'wsgi/api.py',
+]
 apidoc_separate_modules = True
 
 config_generator_config_file = (
diff --git a/releasenotes/notes/add-cinder-wsgi-module-ae72ad42bfebbea8.yaml b/releasenotes/notes/add-cinder-wsgi-module-ae72ad42bfebbea8.yaml
new file mode 100644
index 00000000000..f1ca47d5d6c
--- /dev/null
+++ b/releasenotes/notes/add-cinder-wsgi-module-ae72ad42bfebbea8.yaml
@@ -0,0 +1,22 @@
+---
+features:
+  - |
+    A new module, ``cinder.wsgi``, has been added as a place to gather WSGI
+    ``application`` objects. This is intended to ease deployment by providing
+    a consistent location for these objects. For example, if using uWSGI then
+    instead of:
+
+    .. code-block:: ini
+
+        [uwsgi]
+        wsgi-file = /bin/cinder-wsgi
+
+    You can now use:
+
+    .. code-block:: ini
+
+        [uwsgi]
+        module = cinder.wsgi.api:application
+
+    This also simplifies deployment with other WSGI servers that expect module
+    paths such as gunicorn.