Added NETJSONGRAPH_LINK_EXPIRATION days setting

README.rst

@@ -137,16 +137,19 @@ For a good default ``LOGGING`` configuration refer to the `test settings
 Settings
 --------
 
-+---------------------------------+-------------------------------------+---------------------------------------------------------------------------------------------------+
-| Setting                         | Default value                       | Description                                                                                       |
-+=================================+=====================================+===================================================================================================+
-| ``NETJSONGRAPH_PARSERS``        | ``[]``                              | List with additional custom `netdiff parsers <https://github.com/ninuxorg/netdiff#parsers>`_      |
-+---------------------------------+-------------------------------------+---------------------------------------------------------------------------------------------------+
-| ``NETJSONGRAPH_SIGNALS``        | ``None``                            | String representing python module to import on initialization.                                    |
-|                                 |                                     | Useful for loading django signals or to define custom behaviour.                                  |
-+---------------------------------+-------------------------------------+---------------------------------------------------------------------------------------------------+
-| ``NETJSONGRAPH_TIMEOUT``        | ``8``                               | Timeout when requesting topology URLs                                                             |
-+---------------------------------+-------------------------------------+---------------------------------------------------------------------------------------------------+
++----------------------------------+-------------------------------------+---------------------------------------------------------------------------------------------------+
+| Setting                          | Default value                       | Description                                                                                       |
++==================================+=====================================+===================================================================================================+
+| ``NETJSONGRAPH_PARSERS``         | ``[]``                              | List with additional custom `netdiff parsers <https://github.com/ninuxorg/netdiff#parsers>`_      |
++----------------------------------+-------------------------------------+---------------------------------------------------------------------------------------------------+
+| ``NETJSONGRAPH_SIGNALS``         | ``None``                            | String representing python module to import on initialization.                                    |
+|                                  |                                     | Useful for loading django signals or to define custom behaviour.                                  |
++----------------------------------+-------------------------------------+---------------------------------------------------------------------------------------------------+
+| ``NETJSONGRAPH_TIMEOUT``         | ``8``                               | Timeout when requesting topology URLs                                                             |
++----------------------------------+-------------------------------------+---------------------------------------------------------------------------------------------------+
+| ``NETJSONGRAPH_LINK_EXPIRATION`` | ``60``                              | If a link is down for more days than this number, it will be deleted by the ``update_topology``   |
+|                                  |                                     | management command. Setting this to ``False`` will disable this feature.                          |
++----------------------------------+-------------------------------------+---------------------------------------------------------------------------------------------------+
 
 Installing for development
 --------------------------

django_netjsongraph/settings.py

@@ -11,3 +11,4 @@
 PARSERS = DEFAULT_PARSERS + getattr(settings, 'NETJSONGRAPH_PARSERS', [])
 SIGNALS = getattr(settings, 'NETJSONGRAPH_SIGNALS', None)
 TIMEOUT = getattr(settings, 'NETJSONGRAPH_TIMEOUT', 8)
+LINK_EXPIRATION = getattr(settings, 'NETJSONGRAPH_LINK_EXPIRATION', 60)

django_netjsongraph/tests/test_topology.py

@@ -1,12 +1,16 @@
 import six
+import json
 import responses
+from datetime import timedelta
 
 from django.test import TestCase
 from django.core.management import call_command
+from django.utils.timezone import now
 from netdiff import OlsrParser
 
 from ..models import Topology, Link, Node
 from ..utils import update_topology
+from ..settings import LINK_EXPIRATION
 from .utils import StringIO, LoadMixin, redirect_stdout
 
 
@@ -293,3 +297,40 @@ def test_update_topology_func_unpublished(self):
         update_topology()
         self.assertEqual(Node.objects.count(), 0)
         self.assertEqual(Link.objects.count(), 0)
+
+    @responses.activate
+    def test_delete_expired_links(self):
+        t = Topology.objects.first()
+        t.parser = 'netdiff.NetJsonParser'
+        t.save()
+        # should not delete
+        almost_expired_date = now() - timedelta(days=LINK_EXPIRATION-10)
+        l = Link.objects.create(source_id='d083b494-8e16-4054-9537-fb9eba914861',
+                                target_id='d083b494-8e16-4054-9537-fb9eba914862',
+                                cost=1,
+                                status='down',
+                                topology=t)
+        Link.objects.filter(pk=l.pk).update(created=almost_expired_date,
+                                            modified=almost_expired_date)
+        empty_topology=json.dumps({
+            "type": "NetworkGraph",
+            "protocol": "OLSR",
+            "version": "0.8",
+            "metric": "ETX",
+            "nodes": [],
+            "links": []
+        })
+        responses.add(responses.GET,
+                      'http://127.0.0.1:9090',
+                      body=empty_topology,
+                      content_type='application/json')
+        update_topology('testnetwork')
+        self.assertEqual(Node.objects.count(), 2)
+        self.assertEqual(Link.objects.count(), 1)
+        # should delete
+        expired_date = now() - timedelta(days=LINK_EXPIRATION+10)
+        Link.objects.filter(pk=l.pk).update(created=expired_date,
+                                            modified=expired_date)
+        update_topology('testnetwork')
+        self.assertEqual(Node.objects.count(), 2)
+        self.assertEqual(Link.objects.count(), 0)

django_netjsongraph/utils.py

@@ -1,20 +1,48 @@
 import sys
 
+from datetime import timedelta
+from django.utils.timezone import now
+
 from .contextmanagers import log_on_fail
-from .models import Topology
+from .models import Topology, Link
+from .settings import LINK_EXPIRATION
+
+
+def print_info(message):  # pragma no cover
+    """
+    print info message if calling from management command ``update_topology``
+    """
+    if 'update_topology' in sys.argv:
+        print('{0}\n'.format(message))
+
+
+def delete_expired_links():
+    """
+    deletes links that have been down for more than
+    ``NETJSONGRAPH_LINK_EXPIRATION`` days
+    """
+    if LINK_EXPIRATION not in [False, None]:
+        expiration_date = now() - timedelta(days=int(LINK_EXPIRATION))
+        expired_links = Link.objects.filter(status='down',
+                                            modified__lt=expiration_date)
+        expired_links_length = len(expired_links)
+        if expired_links_length:
+            print_info('Deleting {0} expired links'.format(expired_links_length))
+            for link in expired_links:
+                link.delete()
 
 
 def update_topology(label=None):
     """
-    updates all the topology
-    sends logs to the "nodeshot.networking" logger
+    - updates topologies
+    - logs failures
+    - calls delete_expired_links()
     """
     queryset = Topology.objects.filter(published=True)
     if label:
         queryset = queryset.filter(label__icontains=label)
     for topology in queryset:
-        # print info message if calling from management command
-        if 'update_topology' in sys.argv:  # pragma no cover
-            print('Updating topology {0}\n'.format(topology))
+        print_info('Updating topology {0}'.format(topology))
         with log_on_fail('update', topology):
             topology.update()
+    delete_expired_links()