Refactor the broker module

feudal/backend/models/brokers.py → feudal/backend/brokers.py

 
 from logging import getLogger
-from json import dumps
 
-from django.db import models
-from django.core.cache import cache
-
-import pika
+from pika import BlockingConnection, ConnectionParameters, BasicProperties
 from pika.credentials import PlainCredentials
 
 LOGGER = getLogger(__name__)
 
 
-def publish_to_user(user, obj):
-    from . import serializers
-    RabbitMQInstance.load().publish_to_user(
-        user,
-        dumps(serializers.UpdateSerializer(obj).data),
-    )
-
-def publish_deployment_state(deployment_state):
-    from .serializers.clients import DeploymentStateSerializer
-    RabbitMQInstance.load().publish_deployment_state(
-        deployment_state,
-        dumps(DeploymentStateSerializer(deployment_state).data),
-    )
-
-
-# singleton for simple configs
-# https://steelkiwi.com/blog/practical-application-singleton-design-pattern/
-class SingletonModel(models.Model):
-    class Meta:
-        abstract = True
-
-    def set_cache(self):
-        cache.set(self.__class__.__name__, self)
-
-    # pylint: disable=invalid-name, arguments-differ
-    def save(self, *args, **kwargs):
-        self.pk = 1
-        super(SingletonModel, self).save(*args, **kwargs)
-        self.set_cache()
-
-    @classmethod
-    def load(cls):
-        if cache.get(cls.__name__) is None:
-            obj, created = cls.objects.get_or_create(pk=1)
-            if not created:
-                obj.set_cache()
-        return cache.get(cls.__name__)
-
-
-# The rabbitmq instance located on this host (localhost)
-class RabbitMQInstance(SingletonModel):
+class RabbitMQInstance:
 
     @property
     def host(self):
@@ -84,7 +40,7 @@ class RabbitMQInstance(SingletonModel):
     def _params(self):
         # we set NO port here, we use the default (probably 5672)
         # this requires the
-        return pika.ConnectionParameters(
+        return ConnectionParameters(
             host=self.host,
             virtual_host=self.vhost,
             credentials=PlainCredentials(
@@ -102,7 +58,7 @@ class RabbitMQInstance(SingletonModel):
     def _open_connection(self):
         try:
             # start a new connection
-            return pika.BlockingConnection(self._params)
+            return BlockingConnection(self._params)
         except Exception as e:
             LOGGER.exception('RabbitMQ connection error: %s', e)
             raise e
@@ -118,7 +74,7 @@ class RabbitMQInstance(SingletonModel):
             exchange=exchange,
             routing_key=routing_key,
             body=body,
-            properties=pika.BasicProperties(
+            properties=BasicProperties(
                 delivery_mode=1,
             ),
         )
@@ -148,8 +104,3 @@ class RabbitMQInstance(SingletonModel):
             str(user.id),
             msg,
         )
-
-
-# we keep this, as removing this breaks migrations
-def exchanges_default():
-    return []

feudal/backend/migrations/0001_initial.py

@@ -8,9 +8,9 @@ import django.db.models.deletion
 import django.utils.timezone
 import django_mysql.models
 import feudal.backend.models.auth
-import feudal.backend.models.brokers
 import feudal.backend.models.deployments
 import feudal.backend.models.users
+import feudal.backend.brokers
 
 
 class Migration(migrations.Migration):
@@ -110,7 +110,7 @@ class Migration(migrations.Migration):
                 ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                 ('host', models.CharField(default='localhost', max_length=150)),
                 ('vhost', models.CharField(default='/', max_length=150)),
-                ('exchanges', django_mysql.models.JSONField(blank=True, default=feudal.backend.models.brokers.exchanges_default, null=True)),
+                ('exchanges', django_mysql.models.JSONField(blank=True, default=None, null=True)),
                 ('port', models.IntegerField(default=15672)),
                 ('username', models.CharField(default='guest', max_length=150)),
                 ('password', models.CharField(default='guest', max_length=150)),

feudal/backend/models/deployments.py

 
+from json import dumps
 from logging import getLogger
 
 from django.conf import settings
@@ -11,9 +12,9 @@ from django_mysql.models import JSONField
 from polymorphic.models import PolymorphicModel
 
 from feudal.backend.models import Site, Service
-from feudal.backend.models.brokers import publish_to_user, publish_deployment_state
 from feudal.backend.models.users import User, SSHPublicKey
 from feudal.backend.models.auth.vos import VO
+from feudal.backend.brokers import RabbitMQInstance
 
 
 LOGGER = getLogger(__name__)
@@ -172,11 +173,10 @@ class Deployment(PolymorphicModel):
         if settings.DEBUG_PUBLISHING:
             LOGGER.debug(self.msg('publish_to_user: {}'.format(self.state_target)))
 
-        publish_to_user(
+        from feudal.backend.models.serializers import UpdateSerializer
+        RabbitMQInstance().publish_to_user(
             self.user,
-            {
-                'deployment': self,
-            },
+            dumps(UpdateSerializer({'deployment': self}).data),
         )
 
     def publish(self):
@@ -592,11 +592,10 @@ class DeploymentState(models.Model):
         if settings.DEBUG_PUBLISHING:
             LOGGER.debug(self.msg('publish_to_user'))
 
-        publish_to_user(
+        from feudal.backend.models.serializers import UpdateSerializer
+        RabbitMQInstance().publish_to_user(
             self.user,
-            {
-                'deployment_state': self,
-            },
+            dumps(UpdateSerializer({'deployment_state': self}).data),
         )
 
     def publish_to_client(self):
@@ -618,7 +617,11 @@ class DeploymentState(models.Model):
         if settings.DEBUG_PUBLISHING:
             LOGGER.debug(self.msg('publish_to_client'))
 
-        publish_deployment_state(self)
+        from feudal.backend.models.serializers.clients import DeploymentStateSerializer
+        RabbitMQInstance().publish_deployment_state(
+            self,
+            dumps(DeploymentStateSerializer(self).data),
+        )
 
     def msg(self, msg):
         return ' {} - {}'.format(self, msg)

feudal/backend/models/serializers/clients.py

@@ -6,10 +6,10 @@ from rest_framework.serializers import ModelSerializer, DictField, ListField
 from rest_polymorphic.serializers import PolymorphicSerializer
 
 from feudal.backend.models import Service
-from feudal.backend.models.brokers import RabbitMQInstance
 from feudal.backend.models.users import User, SSHPublicKey
 from feudal.backend.models.deployments import Deployment, VODeployment, ServiceDeployment, DeploymentState, CredentialState
 from feudal.backend.models.auth.serializers.clients import VOSerializer
+from feudal.backend.brokers import RabbitMQInstance
 
 
 class ServiceSerializer(ModelSerializer):

feudal/backend/models/test_deployments.py

@@ -8,6 +8,7 @@ from feudal.backend.models.deployments import (
     Deployment, get_deployment,
     DEPLOYED, NOT_DEPLOYED, DEPLOYMENT_PENDING, REMOVAL_PENDING,
 )
+import feudal.backend.brokers
 
 LOGGER = logging.getLogger(__name__)
 

feudal/backend/views/auth/clients.py

@@ -9,8 +9,8 @@ from django.contrib.sessions.models import Session
 
 from feudal.backend.models import Site, Service
 from feudal.backend.models.users import User
-from feudal.backend.models.brokers import RabbitMQInstance
 from feudal.backend.models.auth.vos import Group, Entitlement
+from feudal.backend.brokers import RabbitMQInstance
 
 LOGGER = logging.getLogger(__name__)
 
@@ -19,7 +19,7 @@ DENY = HttpResponse('deny')
 
 
 def _valid_vhost(request):
-    if request.POST.get('vhost') == RabbitMQInstance.load().vhost:
+    if request.POST.get('vhost') == RabbitMQInstance().vhost:
         return True
     LOGGER.error('illegal vhost requested')
     return False
@@ -139,7 +139,7 @@ def _resource_authorized_apiclient(request):
         and name.startswith('amq.gen-')
     ) or (
         resource == 'exchange'
-        and name in RabbitMQInstance.load().exchanges
+        and name in RabbitMQInstance().exchanges
         and 'write' not in permission
     )
 

feudal/backend/views/auth/test_clients.py

 
-
 from django.test import TestCase, override_settings
 from django.test.client import Client
 
 from feudal.backend.models.auth.vos import Group, Entitlement
-from feudal.backend.models.brokers import RabbitMQInstance
 from feudal.backend.models.users import User
 from feudal.backend.models.auth import OIDCConfig
 from feudal.backend.models import Site, Service
+from feudal.backend.brokers import RabbitMQInstance
 
 
 @override_settings(DEBUG=True, DEBUG_AUTH=True)
@@ -45,7 +44,7 @@ class AuthorizationTestCase(TestCase):
         cls.service.vos.add(cls.group)
         cls.service.vos.add(cls.entitlement)
 
-        cls.broker = RabbitMQInstance.load()
+        cls.broker = RabbitMQInstance()
 
     def setUp(self):
         self.client = Client()

feudal/backend/views/clients.py

@@ -12,8 +12,8 @@ from rest_framework.response import Response
 from feudal.backend.models import Site, Service
 from feudal.backend.models.auth.vos import VO, Group, Entitlement
 from feudal.backend.models.deployments import NOT_DEPLOYED
-from feudal.backend.models.brokers import RabbitMQInstance
 from feudal.backend.models.serializers import clients
+from feudal.backend.brokers import RabbitMQInstance
 from feudal.backend.permissions import DownstreamOnly
 
 LOGGER = logging.getLogger(__name__)
@@ -182,7 +182,7 @@ class ConfigurationView(views.APIView):
         self.apply_vos_to_services(request)
 
         # initialize the broker, just in case
-        broker = RabbitMQInstance.load()
+        broker = RabbitMQInstance()
         broker.initialize()
 
         return Response({