add postgres Fact model, update views, tests

* awx.main.models Fact added
* view host fact and timeline updated to use new Postgres Fact model instead of Mongo
* Removed license set start Mongo logic
* added View tests
* added Model tests
* Removed mongo fact unit tests
* point at modified jsonbfield that supports sqlite storage driver
* postgresify fact cache receiver
* test OPTIONS endpoint
* Note: single fact view not implemented yet.

awx/main/models/fact.py

@@ -2,9 +2,9 @@
 # All Rights Reserved.
 
 from django.db import models
-from jsonbfield.fields import JSONField
+from django.utils.translation import ugettext_lazy as _
 
-from awx.main.models import Host
+from jsonbfield.fields import JSONField
 
 __all__ = ('Fact', )
 
@@ -13,16 +13,19 @@ class Fact(models.Model):
     Facts are stored as JSON dictionaries.
     """
     host = models.ForeignKey(
-        Host,
+        'Host',
         related_name='facts',
         db_index=True,
         on_delete=models.CASCADE,
+        help_text=_('Host for the facts that the fact scan captured.'),
+    )
+    timestamp = models.DateTimeField(
+        default=None, 
+        editable=False, 
+        help_text=_('Date and time of the corresponding fact scan gathering time.')
     )
-    timestamp = models.DateTimeField(default=None, editable=False)
-    created = models.DateTimeField(editable=False, auto_now_add=True)
-    modified = models.DateTimeField(editable=False, auto_now=True)
     module = models.CharField(max_length=128)
-    facts = JSONField(blank=True, default={})
+    facts = JSONField(blank=True, default={}, help_text=_('Arbitrary JSON structure of module facts captured at timestamp for a single host.'))
 
     class Meta:
         app_label = 'main'
@@ -30,3 +33,32 @@ class Fact(models.Model):
             ["timestamp", "module", "host"],
         ]
 
+    @staticmethod
+    def get_host_fact(host_id, module, timestamp):
+        qs = Fact.objects.filter(host__id=host_id, module=module, timestamp__lte=timestamp).order_by('-timestamp')
+        if qs:
+            return qs[0]
+        else:
+            return None
+
+    @staticmethod
+    def get_timeline(host_id, module=None, ts_from=None, ts_to=None):
+        kwargs = {
+            'host__id': host_id,
+        }
+        if module:
+            kwargs['module'] = module
+        if ts_from and ts_to and ts_from == ts_to:
+            kwargs['timestamp'] = ts_from
+        else:
+            if ts_from:
+                kwargs['timestamp__gt'] = ts_from
+            if ts_to:
+                kwargs['timestamp__lte'] = ts_to
+        return Fact.objects.filter(**kwargs).order_by('-timestamp').only('timestamp', 'module').order_by('-timestamp', 'module')
+
+    @staticmethod
+    def add_fact(host_id, module, timestamp, facts):
+        fact_obj = Fact.objects.create(host_id=host_id, module=module, timestamp=timestamp, facts=facts)
+        fact_obj.save()
+        return fact_obj