Notification serializers, views, and tasks

* Implement concrete Notification model for notification runs
* Implement NotificationTemplate and Notification serializers and views
* Implement ancillary views
* Implement NotificationTemplate trigger m2m fields on all job templates
  via a fields mixin
* Link NotificationTemplates with an org
* Link notifications with the activity stream
* Implement Notification celery tasks
* Extend Backend field parameters to identify sender and receiver as
  parameters needed by the message and not the backend itself
* Updates to backends to better fit the django email backend model as it
  relates to Messages
* Implement success job chain task + notifications
* Implement notifications in error job chain task

awx/main/models/notifications.py

@@ -5,7 +5,9 @@ import logging
 
 from django.db import models
 from django.core.urlresolvers import reverse
+from django.core.mail.message import EmailMessage
 from django.utils.translation import ugettext_lazy as _
+from django.utils.encoding import smart_str
 
 from awx.main.models.base import * # noqa
 from awx.main.notifications.email_backend import CustomEmailBackend
@@ -17,7 +19,7 @@ from jsonfield import JSONField
 
 logger = logging.getLogger('awx.main.models.notifications')
 
-__all__ = ['NotificationTemplate']
+__all__ = ['NotificationTemplate', 'Notification']
 
 class NotificationTemplate(CommonModel):
 
@@ -30,6 +32,14 @@ class NotificationTemplate(CommonModel):
     class Meta:
         app_label = 'main'
 
+    organization = models.ForeignKey(
+        'Organization',
+        blank=False,
+        null=True,
+        on_delete=models.SET_NULL,
+        related_name='notification_templates',
+    )
+
     notification_type = models.CharField(
         max_length = 32,
         choices=NOTIFICATION_TYPE_CHOICES,
@@ -42,4 +52,83 @@ class NotificationTemplate(CommonModel):
 
     @property
     def notification_class(self):
-        return CLASS_FOR_NOTIFICATION_TYPE[self.notification_type]
+        return self.CLASS_FOR_NOTIFICATION_TYPE[self.notification_type]
+
+    @property
+    def recipients(self):
+        return self.notification_configuration[self.notification_class.recipient_parameter]
+
+    def generate_notification(self, subject, message):
+        notification = Notification(notifier=self,
+                                    notification_type=self.notification_type,
+                                    recipients=smart_str(self.recipients),
+                                    subject=subject,
+                                    body=message)
+        notification.save()
+        return notification
+
+    def send(self, subject, body):
+        recipients = self.notification_configuration.pop(self.notification_class.recipient_parameter)
+        sender = self.notification_configuration.pop(self.notification_class.sender_parameter, None)
+        backend_obj = self.notification_class(**self.notification_configuration)
+        notification_obj = EmailMessage(subject, body, sender, recipients)
+        return backend_obj.send_messages([notification_obj])
+
+class Notification(CreatedModifiedModel):
+    '''
+    A notification event emitted when a Notifier is run
+    '''
+
+    NOTIFICATION_STATE_CHOICES = [
+        ('pending', _('Pending')),
+        ('successful', _('Successful')),
+        ('failed', _('Failed')),
+    ]
+
+    class Meta:
+        app_label = 'main'
+        ordering = ('pk',)
+
+    notifier = models.ForeignKey(
+        'NotificationTemplate',
+        related_name='notifications',
+        on_delete=models.CASCADE,
+        editable=False
+    )
+    status = models.CharField(
+        max_length=20,
+        choices=NOTIFICATION_STATE_CHOICES,
+        default='pending',
+        editable=False,
+    )
+    error = models.TextField(
+        blank=True,
+        default='',
+        editable=False,
+    )
+    notifications_sent = models.IntegerField(
+        default=0,
+        editable=False,
+    )
+    notification_type = models.CharField(
+        max_length = 32,
+        choices=NotificationTemplate.NOTIFICATION_TYPE_CHOICES,
+    )
+    recipients = models.TextField(
+        blank=True,
+        default='',
+        editable=False,
+    )
+    subject = models.TextField(
+        blank=True,
+        default='',
+        editable=False,
+    )
+    body = models.TextField(
+        blank=True,
+        default='',
+        editable=False,
+    )
+    
+    def get_absolute_url(self):
+        return reverse('api:notification_detail', args=(self.pk,))