Upgrade to Python 3.11 and GAE Gen 2 (#29)

* Remove locked `google-auth` version

* This helps resolve the ResolutionImpossible error while installing
  packages from requirements.txt on Python 3.11

* Change runtime to `python311`

* Remove `libraries` entry from `app.yaml`

* Update `Jinja2` package for compatibility

* Enable legacy bundled services on Python3 runtime
* https://cloud.google.com/appengine/docs/standard/python3/services/access

* Drop `lib` dir

* Point `gae-sessions` to `python3-compat` branch

* Remove no longer supported fields from `app.yaml`
* https://cloud.google.com/appengine/docs/standard/python3/migrate-to-python3/config-files

* Remove `threadsafe` entry from `app.yaml`
* All apps are presumed to be threadsafe in Python3 runtime
* https://cloud.google.com/appengine/docs/standard/python3/migrate-to-python3/config-files

* Replace `handlers: script` value w/ `auto`
* https://cloud.google.com/appengine/docs/standard/python3/migrate-to-python3/config-files#python-3

* Remove `env_variables` section from `app.yaml`
* The `DJANGO_SETTINGS_MODULE` env variable had to be set to the name of the Django settings module, typically 'settings', before packages got imported back on the legacy Python2 runtime
* https://cloud.google.com/appengine/docs/legacy/standard/python/tools/using-libraries-python-27#django

* Remove ignored `appengine_config.py`
* https://cloud.google.com/appengine/migration-center/standard/migrate-to-second-gen/python-differences#configuration
* Replaced w/ a call to `wrap_wsgi_app`
* The new `wrap_wsgi_middleware` decorator is created to configure `SessionMiddleware`

* Replace `CURRENT_VERSION_ID` w/ `GAE_VERSION`

* `GAE_VERSION` holds the current version label of the service
* https://cloud.google.com/appengine/docs/standard/python3/runtime#environment_variables

* Determine environment using `GAE_ENV` variable

* Update `ae_helpers`

* Disable "file_cache is unavailable" warning

* This disables the following warning produced by `googleapiclient`

    WARNING:googleapiclient.discovery_cache:file_cache is unavailable when using oauth2client >= 4.0.0 or google-auth

* googleapis/google-api-python-client#299

* Add `.gcloudignore`

.gcloudignore

@@ -0,0 +1,23 @@
+# This file specifies files that are *not* uploaded to Google Cloud
+# using gcloud. It follows the same syntax as .gitignore, with the addition of
+# "#!include" directives (which insert the entries of the given .gitignore-style
+# file at that point).
+#
+# For more information, run:
+#   $ gcloud topic gcloudignore
+#
+.gcloudignore
+# If you would like to upload your .git directory, .gitignore file or files
+# from your .gitignore file, remove the corresponding line
+# below:
+.git
+.gitignore
+
+# Python pycache:
+__pycache__/
+# Ignored by the build system
+/setup.cfg
+
+output/
+tests/
+venv/

app.yaml

@@ -1,6 +1,5 @@
-runtime: python27
-threadsafe: true
-api_version: 1
+runtime: python311
+app_engine_apis: true # from https://pypi.org/project/appengine-python-standard/
 
 handlers:
 - url: /favicon\.ico
@@ -17,16 +16,4 @@ handlers:
   static_dir: static/css
 
 - url: .*
-  script: main.app
-
-libraries:
-- name: lxml
-  version: latest
-- name: ssl
-  version: 2.7.11
-
-builtins:
-- appstats: on
-
-env_variables:
-  DJANGO_SETTINGS_MODULE: 'settings'
+  script: auto

auth.py

@@ -82,7 +82,7 @@ def oauth2_callback():
     # When running locally, disable OAuthlib's HTTPs verification.
     # This is to get rid of the following error in development:
     #   InsecureTransportError: (insecure_transport) OAuth 2 MUST utilize https.
-    if os.environ.get('HTTPS') == 'off':
+    if os.environ.get('GAE_ENV') == 'localdev':
         os.environ['OAUTHLIB_INSECURE_TRANSPORT'] = '1'
 
     session = get_current_session()
@@ -122,7 +122,7 @@ def oauth2_callback():
     ae_save(access_token, access_token_key)
 
     try:
-        calendar_service = build('calendar', 'v3', credentials=credentials)
+        calendar_service = build('calendar', 'v3', credentials=credentials, cache_discovery=False)
 
         # CalendarList#list API ref:
         #   https://developers.google.com/calendar/api/v3/reference/calendarList/list

events_calendar.py

@@ -85,7 +85,7 @@ def create_calendar_events(user, event_list):
     # After obtaining an access token, your application can use that token to authorize API requests on behalf of a given user account.
     # Use the user-specific authorization credentials to build a service object for the API that you want to call,
     # and then use that object to make authorized API requests.
-    calendar_service = build('calendar', 'v3', credentials=credentials)
+    calendar_service = build('calendar', 'v3', credentials=credentials, cache_discovery=False)
     for event in event_list:
         insert_event(calendar_service, event.title, event.description, event.location, event.starttime, event.endtime,
                         user.calendar_id)