Refactor rabbitmq interaction

django_backend/backend/models.py

@@ -4,11 +4,11 @@ from django.conf import settings
 from django.dispatch import receiver, Signal
 from django.utils.timezone import make_aware
 from rest_framework.authtoken.models import Token
-from django.db.models.signals import post_save, m2m_changed
+from django.db.models.signals import post_save
+# from django.db.models.signals import m2m_changed
 from datetime import datetime
 
-import requests
-from requests.auth import HTTPBasicAuth
+from .rabbitmq import RabbitMQInstance
 
 deployment_change = Signal(providing_args=['instance'])
 
@@ -95,76 +95,12 @@ class Site(models.Model):
 
 
 @receiver(post_save, sender=Site)
-def register_client_at_rabbitmq(sender, instance=None, created=False,
-                                **kwargs):
+def register_at_rabbitmq(
+        sender, instance=None, created=False, **kwargs):
     if not created:
         return
 
-    print('registerring client {}'.format(instance.client.username))
-
-    # %2f: url encoded '/' as this is the vhost we use
-    api = 'http://localhost:15672/api'
-    username = instance.client.username
-    vhost = '%2f'
-    exchange = 'deployments'
-    # guest only works on the localhost
-    auth = HTTPBasicAuth('guest', 'guest')
-
-    # create user
-    user_creation_uri = '{}/users/{}/'.format(
-            api,
-            username
-            )
-    user_creation_data = {
-            'password': str(instance.client.auth_token.key),
-            'tags': '',
-            }
-    r = requests.put(user_creation_uri, json=user_creation_data, auth=auth)
-    print('status_code {} {}'.format(r.status_code, r.text))
-
-    # set permissions for the user
-    set_permission_uri = '{}/permissions/{}/{}/'.format(
-            api,
-            vhost,
-            username,
-            )
-    permission = '^(amq\.gen.*|{})'.format(exchange)
-    set_permission_data = {
-            'configure': permission,
-            'write': permission,
-            'read': permission,
-            }
-
-    set_topic_permission_uri = '{}/topic-permissions/{}/{}/'.format(
-            api,
-            vhost,
-            username,
-            )
-    r = requests.put(set_permission_uri, json=set_permission_data, auth=auth)
-    print('status_code {} {}'.format(r.status_code, r.text))
-
-    # set permissions for the correct topics
-    # we construct a regex to match the services of the site
-    services = ''
-    omitBar = True
-    for service in instance.services.all():
-        prefix = '|'
-        if omitBar:
-            prefix = ''
-            omitBar = False
-
-        services = services + prefix + service.name
-
-    set_topic_permission_data = {
-            'exchange': exchange,
-            'write': '^$',
-            'read': '^service\.({})$'.format(services),
-            }
-
-    r = requests.put(
-            set_topic_permission_uri,
-            json=set_topic_permission_data, auth=auth)
-    print('status_code {} {}'.format(r.status_code, r.text))
+    RabbitMQInstance().register_site(instance)
 
 
 class Service(models.Model):

django_backend/backend/rabbitmq.py

+
+import requests
+from requests.auth import HTTPBasicAuth
+
+
+# clients are registerred at rabbitmq, when they are assigned to a site
+# (because we only then know what services they provide)
+class RabbitMQInstance:
+    def __init__(self):
+        self.api = 'http://localhost:15672/api'
+        # %2f: url encoded '/' as this is the vhost we use
+        self.vhost = '%2f'
+        self.exchange = 'deployments'
+        # guest only works on the localhost
+        self.auth = HTTPBasicAuth('guest', 'guest')
+
+    def set_topic_permissions(self, site):
+        username = site.client.username
+        set_topic_permission_uri = '{}/topic-permissions/{}/{}/'.format(
+                self.api,
+                self.vhost,
+                username,
+                )
+
+        # set permissions for the correct topics
+        # we construct a regex to match the services of the site
+        services = ''
+        omitBar = True
+        for service in site.services.all():
+            prefix = '|'
+            if omitBar:
+                prefix = ''
+                omitBar = False
+
+            services = services + prefix + service.name
+
+        set_topic_permission_data = {
+                'exchange': self.exchange,
+                'write': '^$',
+                'read': '^service\.({})$'.format(services),
+                }
+
+        # TODO might fail
+        r = requests.put(
+                set_topic_permission_uri,
+                json=set_topic_permission_data, auth=self.auth)
+
+        print('RabbitMQ: set_topic_permissions {}'.format(r.status_code))
+
+    # set permissions for the user
+    def set_permissions(self, site):
+        username = site.client.username
+        set_permission_uri = '{}/permissions/{}/{}/'.format(
+                self.api,
+                self.vhost,
+                username,
+                )
+        permission = '^(amq\.gen.*|{})'.format(self.exchange)
+        set_permission_data = {
+                'configure': permission,
+                'write': permission,
+                'read': permission,
+                }
+
+        # TODO might fail
+        r = requests.put(
+                set_permission_uri, json=set_permission_data, auth=self.auth)
+        print('RabbitMQ: set_permissions {}'.format(r.status_code))
+
+    # create user at the rabbitmq instance
+    def create_user(self, site):
+        username = site.client.username
+        user_creation_uri = '{}/users/{}/'.format(
+                self.api,
+                username
+                )
+
+        print('registerring client {}'.format(site.client.username))
+
+        user_creation_data = {
+                'password': str(site.client.auth_token.key),
+                'tags': '',
+                }
+        # TODO might fail
+        r = requests.put(
+                user_creation_uri, json=user_creation_data, auth=self.auth)
+        print('RabbitMQ: create_user {}'.format(r.status_code))
+
+    # delete user at the rabbitmq instance
+    def delete_user(self, site):
+        username = site.client.username
+        user_creation_uri = '{}/users/{}/'.format(
+                self.api,
+                username
+                )
+
+        print('registerring client {}'.format(site.client.username))
+
+        user_creation_data = {
+                'password': str(site.client.auth_token.key),
+                'tags': '',
+                }
+        # TODO might fail
+        r = requests.delete(
+                user_creation_uri, json=user_creation_data, auth=self.auth)
+        print('RabbitMQ: create_user {}'.format(r.status_code))
+
+    def register_site(self, site):
+        self.create_user(site)
+        self.set_permissions(site)
+        self.set_topic_permissions(site)