Add wsgi module to freezer-api

Changes in python packaging tooling mean that the wsgi_scripts
functionality via PBR may not longer function.

We migrate freezer to use wsgi modules to ensure consistent behavior
and achieve the community goal.

For more details see the proposed OpenStack goal [1].

We also fix compatability with Falcon 4.1 which is a requirements for
2026.1

[1] https://review.opendev.org/c/openstack/governance/+/902807

Change-Id: I6f73ee5fe6194d2a5390dfb5389e336719332cb1
Signed-off-by: Dmitriy Rabotyagov <noonedeadpunk@gmail.com>

devstack/lib/freezer-api

@@ -143,6 +143,11 @@ function configure_freezer_api {
     sudo chown $STACK_USER $FREEZER_API_AUTH_CACHE_DIR/registry
     rm -f $FREEZER_API_AUTH_CACHE_DIR/registry/*
 
+    # configure logs
+    if [ -n "$BASE" ] && [ -d "$BASE/logs" ]; then
+        sudo ln -sf $FREEZER_API_LOG_DIR/freezer-api.log $BASE/logs/freezer-api-post.log
+    fi
+
     # set keystone configuration
     configure_auth_token_middleware $FREEZER_API_CONF freezer $FREEZER_API_AUTH_CACHE_DIR/api
 
@@ -299,7 +304,7 @@ function configure_uwsgi_freezer_api_app {
     iniset $FREEZER_API_UWSGI_CONF 'uwsgi'  http $local_http
     iniset $FREEZER_API_UWSGI_CONF 'uwsgi' processes 2
     iniset $FREEZER_API_UWSGI_CONF 'uwsgi' threads 2
-    iniset $FREEZER_API_UWSGI_CONF 'uwsgi' wsgi-file $FREEZER_API_DIR/freezer_api/cmd/wsgi.py
+    iniset $FREEZER_API_UWSGI_CONF 'uwsgi' wsgi freezer_api.wsgi:application
 
     # Make sure the client doesn't try to re-use the connection.
     iniset $FREEZER_API_UWSGI_CONF 'uwsgi' add-header "Connection: close"

etc/freezer/freezer-paste.ini

@@ -10,8 +10,8 @@ paste.app_factory = freezer_api.service:freezer_appv2_factory
 [filter:authtoken]
 paste.filter_factory = keystonemiddleware.auth_token:filter_factory
 
-[filter:healthcheck]
-paste.filter_factory = oslo_middleware:Healthcheck.factory
+[app:healthcheck]
+paste.app_factory = oslo_middleware:Healthcheck.app_factory
 backends = disable_by_file
 disable_by_file_path = /etc/freezer/healthcheck_disable
 
@@ -24,11 +24,21 @@ paste.filter_factory = freezer_api.api.versions:VersionNegotiator.factory
 [filter:http_proxy_to_wsgi]
 paste.filter_factory = oslo_middleware:HTTPProxyToWSGI.factory
 
-[pipeline:main]
-pipeline = healthcheck http_proxy_to_wsgi versionsNegotiator authtoken context backupapp
+[composite:main]
+use = egg:Paste#urlmap
+/healthcheck = healthcheck
+/ = api
 
-[pipeline:unauthenticated_freezer_api]
-pipeline = http_proxy_to_wsgi healthcheck freezer_app
+[pipeline:api]
+pipeline = http_proxy_to_wsgi versionsNegotiator authtoken context backupapp
+
+[composite:unauthenticated_freezer_api]
+use = egg:Paste#urlmap
+/healthcheck = healthcheck
+/ = unauthenticated_api
+
+[pipeline:unauthenticated_api]
+pipeline = http_proxy_to_wsgi freezer_app
 
 [composite:backupapp]
 paste.composite_factory = freezer_api.service:root_app_factory

etc/freezer/uwsgi.conf

@@ -5,7 +5,7 @@ strict = true
 http = :9090
 processes = 2
 threads = 2
-wsgi-file = /opt/stack/freezer-api/freezer_api/cmd/wsgi.py
+wsgi = freezer_api.wsgi:application
 callable = app
 master = true
 add-header = Connection: close

freezer_api/api/common/middleware.py

@@ -131,7 +131,8 @@ class RequireJSON(HookableMiddlewareMixin, object):
     def process_request(self, req, resp):
         if not req.client_accepts_json:
             raise falcon.HTTPNotAcceptable(
-                'Freezer-api only supports responses encoded as JSON.',
+                description='Freezer-api only supports responses encoded '
+                            'as JSON.',
                 href='http://docs.examples.com/api/json')
 
 

freezer_api/api/common/resource.py

@@ -38,5 +38,5 @@ class BaseResource(object):
             json_data = json.loads(raw_json, encoding='utf-8')
         except ValueError:
             raise falcon.HTTPError(falcon.HTTP_753,
-                                   'Malformed JSON')
+                                   title='Malformed JSON')
         return json_data

freezer_api/wsgi.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 the Blazar API."""
+
+import threading
+
+from freezer_api.service import initialize_app
+
+application = None
+
+lock = threading.Lock()
+with lock:
+    if application is None:
+        application = initialize_app()

releasenotes/notes/wsgi_module-471cb41a14109df6.yaml

@@ -0,0 +1,28 @@
+---
+features:
+  - |
+    A new module, ``freezer_api.wsgi``, has been added as a place to provide
+    WSGI. For example, if using uWSGI then instead of:
+
+    .. code-block:: ini
+
+        [uwsgi]
+        wsgi-file = /bin/freezer-api-wsgi
+
+    You can now use:
+
+    .. code-block:: ini
+
+        [uwsgi]
+        wsgi = freezer_api.wsgi:application
+
+    This also simplifies deployment with other WSGI servers that expect module
+    paths such as gunicorn.
+
+upgrade:
+  - |
+    The WSGI script ``freezer-api-wsgi`` has been removed. Deployment tooling
+    should instead reference the Python module path for the wsgi module in
+    Freezer, ``freezer_api.wsgi:application`` if their chosen WSGI server
+    supports this (gunicorn, uWSGI, etc.) or implement a .wsgi script
+    themselves if not (mod_wsgi).

releasenotes/source/conf.py

@@ -30,9 +30,9 @@ extensions = [
 ]
 
 # openstackdocstheme options
-repository_name = 'openstack/freezer-api'
-bug_project = 'freezer'
-bug_tag = 'release notes'
+openstackdocs_repo_name = 'openstack/freezer-api'
+openstackdocs_bug_project = 'freezer'
+openstackdocs_bug_tag = 'release notes'
 
 html_last_updated_fmt = '%Y-%m-%d %H:%M'
 

setup.cfg

@@ -50,8 +50,6 @@ console_scripts =
     freezer-api = freezer_api.cmd.api:main
     freezer-manage = freezer_api.cmd.manage:main
     freezer-manager-status = freezer_api.cmd.status:main
-wsgi_scripts =
-    freezer-api-wsgi = freezer_api.service:initialize_app
 
 freezer.db.backends =
      sqlalchemy = freezer_api.db.sqlalchemy.driver:SQLDriver