global: prepare for future Flask upgrades

Prepare for future Flask breaking changes, in particular:
- rename some parameters of `send_file`, as they will be removed in
  Flask 2.2
- fix how the Flask app is detected in our custom scripts, as
  `with_appcontext` will change behaviour in Flask 2.2

Author: mdonadoni

reana_workflow_controller/rest/utils.py

@@ -28,7 +28,7 @@
 from typing import Dict, List, Optional, Union
 from uuid import UUID
 
-from flask import jsonify, request, send_file, send_from_directory
+from flask import jsonify, request, send_file
 from git import Repo
 from kubernetes.client.rest import ApiException
 from reana_commons import workspace
@@ -562,7 +562,7 @@ def _send_zipped_dir_or_files(workflow_name, dir_path=None, file_paths=None):
         memory_file.seek(0)
         return send_file(
             memory_file,
-            attachment_filename=filename,
+            download_name=filename,
             as_attachment=True,
             mimetype="application/zip",
         )
@@ -580,7 +580,7 @@ def _send_single_file(workspace_path: str, relative_file_path: str):
                 workspace.open_file(workspace_path, relative_file_path, mode="rb"),
                 mimetype=response_mime_type,
                 as_attachment=response_mime_type == default_response_mime_type,
-                attachment_filename=relative_file_path,
+                download_name=relative_file_path,
             ),
             200,
         )

scripts/generate_openapi_spec.py

@@ -16,11 +16,11 @@
 from apispec import APISpec
 from apispec_webframeworks.flask import FlaskPlugin
 from flask import current_app
-from flask.cli import with_appcontext
 from reana_commons.utils import copy_openapi_specs
 from swagger_spec_validator.validator20 import validate_json
 
 from reana_workflow_controller.version import __version__
+from reana_workflow_controller.app import app
 
 # Import your marshmallow schemas here
 # from example_package.schemas import Example_schema,
@@ -44,7 +44,6 @@
     "E.g. --publish.",
     count=True,
 )
-@with_appcontext
 def build_openapi_spec(publish):
     """Creates an OpenAPI definition of Flask application,
     check conformity of generated definition against OpenAPI 2.0 specification
@@ -108,4 +107,5 @@ def build_openapi_spec(publish):
 
 
 if __name__ == "__main__":
-    build_openapi_spec()
+    with app.app_context():
+        build_openapi_spec()