Add support for pyproject.toml and wsgi module paths

pip 23.1 removed the "setup.py install" fallback for projects that do
not have pyproject.toml and now uses a pyproject.toml which is vendored
in pip [1][2]. pip 24.2 has now deprecated a similar fallback to
"setup.py develop" and plans to fully remove this in pip 25.0 [3][4][5].
pbr supports editable installs since 6.0.0

pip 25.1 has now been released and the removal is complete.
by adding our own minimal pyproject.toml to ensure we are using the
correct build system.

This change also requires that we adapt how we generate our wsgi
entry point. when pyproject.toml is used the wsgi console script is
not generated in an editbale install such as is used in devstck

To adress this we need to refactor our usage of our wsgi applciation
to use a module path instead. This change does not remove
the declaration of our wsgi_script entry point but it shoudl
be considered deprecated and it will be removed in the future.

To unblock the gate the devstack plugin is modifed to to deploy
using the wsgi module instead of the console script.

[1] https://pip.pypa.io/en/stable/news/#v23-1
[2] pypa/pip#8368
[3] https://pip.pypa.io/en/stable/news/#v24-2
[4] pypa/pip#11457
[5] https://ichard26.github.io/blog/2024/08/whats-new-in-pip-24.2/
Closes-Bug: #2109583

Change-Id: I31fb6bff75ce27aedd94f7f73b7bfdd706127fc2

cyborg/wsgi/api.py

@@ -0,0 +1,22 @@
+#    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 Cyborg API."""
+
+import threading
+
+from cyborg.api import wsgi_app
+
+application = None
+lock = threading.Lock()
+with lock:
+    if application is None:
+        application = wsgi_app.init_application()

devstack/lib/cyborg

@@ -149,7 +149,7 @@ function configure_cyborg_api {
     iniset $CYBORG_CONF_FILE conductor automated_clean $CYBORG_AUTOMATED_CLEAN_ENABLED
 
     if [ "$CYBORG_USE_UWSGI" == "True" ]; then
-        write_uwsgi_config "$CYBORG_UWSGI_CONF" "$CYBORG_UWSGI" "/accelerator"
+        write_uwsgi_config "$CYBORG_UWSGI_CONF" "$CYBORG_UWSGI" "/accelerator" "" "cyborg-api"
     fi
     sudo cp -p $CYBORG_DIR/etc/cyborg/api-paste.ini $CYBORG_API_PASTE_INI
 }

devstack/settings

@@ -29,7 +29,7 @@ fi
 # Toggle for deploying Cyborg-API under a wsgi server
 CYBORG_USE_UWSGI=${CYBORG_USE_UWSGI:-True}
 
-CYBORG_UWSGI=$CYBORG_BIN_DIR/cyborg-wsgi-api
+CYBORG_UWSGI=cyborg.wsgi.api:application
 CYBORG_UWSGI_CONF=$CYBORG_CONF_DIR/cyborg-api-uwsgi.ini
 
 if [[ "$CYBORG_USE_UWSGI" == "True" ]]; then

pyproject.toml

@@ -0,0 +1,3 @@
+[build-system]
+requires = ["pbr>=6.0.0", "setuptools>=64.0.0"]
+build-backend = "pbr.build"

releasenotes/notes/add-wsgi-module-supprot-e61a368fcf39a921.yaml

@@ -0,0 +1,30 @@
+---
+features:
+  - |
+    A new module, ``cyborg.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/cyborg-api-wsgi
+
+    You can now use:
+
+    .. code-block:: ini
+
+        [uwsgi]
+        module = cyborg.wsgi.api:application
+
+    This also simplifies deployment with other WSGI servers that expect module
+    paths such as gunicorn.
+deprecations:
+  - |
+    The cyborg-api-wsgi console script is deprecated for removal
+    in a future release. This artifact is generated using a setup-tools
+    extension that is provide by PBR which is also deprecated.
+    Due to the changes in python packaging this custom extensions
+    is planned to be removed form all OpenStack projects in a future
+    PBR release in favor of module based wsgi applications entry points.

setup.cfg

@@ -6,7 +6,7 @@ description_file =
 author = OpenStack
 author_email = openstack-discuss@lists.openstack.org
 home_page = https://docs.openstack.org/cyborg/latest/
-python_requires = >=3.8
+python_requires = >=3.10
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -17,8 +17,6 @@ classifier =
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.8
-    Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3.11
 
@@ -40,6 +38,9 @@ console_scripts =
     cyborg-dbsync = cyborg.cmd.dbsync:main
     cyborg-agent = cyborg.cmd.agent:main
     cyborg-status = cyborg.cmd.status:main
+
+# NOTE(sean-k-mooney): this should be removed in 2026.1
+# as this will eventually stop working entirely.
 wsgi_scripts =
     cyborg-wsgi-api = cyborg.api.wsgi_app:init_application
 

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.18.0
-envlist = py38,pep8
+envlist = py3,pep8
 # Automatic envs (pyXX) will only use the python version appropriate to that
 # env and ignore basepython inherited from [testenv] if we set
 # ignore_basepython_conflict.