Add uber simple Oslo.Messaging notifier for sending messages.

Add uber simple Oslo.Messaging notifier for sending messages.

Change-Id: I5ac4bafbb02cb4dfb79e5892e5b9fc42d9162807

nemesis.conf.sample

@@ -1,4 +1,6 @@
 [DEFAULT]
+rpc_backend = rabbit
+transport_url = rabbit://<user>:<password>@<host>/<vhost>
 
 [keystone_authtoken]
 identity_uri =

python_nemesis/api/v1/__init__.py

@@ -12,22 +12,19 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import datetime
 from flask import Blueprint
 from flask import jsonify
 from flask import request
-from flask_keystone import current_user
 import os
 from python_nemesis.db.utilities import add_request
-from python_nemesis.db.utilities import create_new_file
-from python_nemesis.db.utilities import get_file_by_sha512_hash
+from python_nemesis.db.utilities import create_or_renew_by_hash
 from python_nemesis.db.utilities import search_by_hash
 from python_nemesis.exceptions import general_handler
 from python_nemesis.exceptions import NemesisException
 from python_nemesis.exceptions import NotFoundException
-from python_nemesis.extensions import db
 from python_nemesis.extensions import log
 from python_nemesis.file_hasher import get_all_hashes
+from python_nemesis.notifications import submit_worker_notification
 from python_nemesis.swift import upload_to_swift
 import uuid
 from werkzeug.utils import secure_filename
@@ -69,47 +66,37 @@ def lookup_hash(req_hash):
 
 @V1_API.route('/v1/file', methods=['POST'])
 def post_file():
-    filename = secure_filename(str(uuid.uuid4()))
-    filename = '/tmp/%s' % filename
+    file_uuid = secure_filename(str(uuid.uuid4()))
+    filename = '/tmp/%s' % file_uuid
     file = request.files['file']
 
     if 'Content-Range' in request.headers:
-        # extract starting byte from Content-Range header string
+        # Extract starting byte from Content-Range header string.
         range_str = request.headers['Content-Range']
         start_bytes = int(range_str.split(' ')[1].split('-')[0])
 
-        # append chunk to the file on disk, or create new
+        # Append chunk to the file on disk, or create new.
         with open(filename, 'a') as f:
             f.seek(start_bytes)
             f.write(file.stream.read())
 
     else:
-        # this is not a chunked request, so just save the whole file
+        # This is not a chunked request, so just save the whole file.
         file.save(filename)
 
+    # Generate hash of file, and create new, or renew existing db row.
     file_hashes = get_all_hashes(filename)
-    current_file = get_file_by_sha512_hash(file_hashes['sha512'])
     file_size = os.path.getsize(filename)
-
-    if current_file:
-        current_file.last_updated = datetime.datetime.now()
-        current_file.status = 'analysing'
-        db.session.commit()
-        file_id = current_file.file_id
-        file_dict = current_file.to_dict()
-
-    else:
-        file = create_new_file(file_hashes['md5'],
-                               file_hashes['sha1'],
-                               file_hashes['sha256'],
-                               file_hashes['sha512'],
-                               file_size,
-                               current_user.user_id)
-        file_id = file.file_id
-        file_dict = file.to_dict()
+    file = create_or_renew_by_hash(file_hashes, file_size)
+    file_id = file.file_id
+    file_dict = file.to_dict()
 
     # Upload to swift and remove the local temp file.
-    upload_to_swift(filename, file_id)
+    upload_to_swift(filename, file_uuid)
     os.remove(filename)
 
+    # Send message to worker queue with file details.
+    worker_msg = {"file_uuid": file_uuid, "file_id": file_id}
+    submit_worker_notification(worker_msg)
+
     return jsonify(file_dict)

python_nemesis/base_app.py

@@ -13,6 +13,7 @@
 from flask import Flask
 import os
 from oslo_config import cfg
+import oslo_messaging
 from python_nemesis.config import collect_sqlalchemy_opts
 from python_nemesis.config import register_opts
 from python_nemesis.extensions import db
@@ -68,6 +69,15 @@ def configure_extensions(app):
     keystone.init_app(app)
 
 
+def configure_notifier(app):
+    transport = oslo_messaging.get_notification_transport(app.config['cfg'])
+    topics = ['nemesis_notifications']
+    app.config["notifier"] = oslo_messaging.Notifier(transport,
+                                                     'nemesis.api',
+                                                     driver='messagingv2',
+                                                     topics=topics)
+
+
 def create_app(app_name=None, blueprints=None):
     """Create the flask app.
 
@@ -84,6 +94,7 @@ def create_app(app_name=None, blueprints=None):
 
     configure_app(app)
     configure_extensions(app)
+    configure_notifier(app)
 
     # Here we register the application blueprints.
     from python_nemesis.api.v1 import V1_API

python_nemesis/db/utilities.py

@@ -70,3 +70,22 @@ def create_new_file(md5_hash, sha1_hash, sha256_hash, sha512_hash,
     db.session.add(file)
     db.session.commit()
     return file
+
+
+def create_or_renew_by_hash(hashes, file_size):
+    current_file = get_file_by_sha512_hash(hashes['sha512'])
+
+    if current_file:
+        current_file.last_updated = datetime.datetime.now()
+        current_file.status = 'analysing'
+        db.session.commit()
+        return current_file
+
+    else:
+        file = create_new_file(hashes['md5'],
+                               hashes['sha1'],
+                               hashes['sha256'],
+                               hashes['sha512'],
+                               file_size,
+                               current_user.user_id)
+        return file

python_nemesis/notifications.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+
+# 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.
+
+
+from flask import current_app
+
+
+def submit_worker_notification(msg):
+    notifier = current_app.config['notifier']
+    notifier.info({}, 'nemsis.new_file', msg)