#1246: Initial work on an API endpoint to retrieve available IPs for a prefix

netbox/ipam/api/views.py

@@ -1,7 +1,12 @@
 from __future__ import unicode_literals
 
+from rest_framework.decorators import detail_route
+from rest_framework.response import Response
 from rest_framework.viewsets import ModelViewSet
 
+from django.conf import settings
+from django.shortcuts import get_object_or_404
+
 from ipam.models import Aggregate, IPAddress, Prefix, RIR, Role, Service, VLAN, VLANGroup, VRF
 from ipam import filters
 from extras.api.views import CustomFieldModelViewSet
@@ -61,6 +66,33 @@ class PrefixViewSet(WritableSerializerMixin, CustomFieldModelViewSet):
     write_serializer_class = serializers.WritablePrefixSerializer
     filter_class = filters.PrefixFilter
 
+    @detail_route(url_path='available-ips')
+    def available_ips(self, request, pk=None):
+        """
+        A convenience method for returning available IP addresses within a prefix. By default, the number of IPs
+        returned will be equivalent to PAGINATE_COUNT. An arbitrary limit (up to MAX_PAGE_SIZE, if set) may be passed,
+        however results will not be paginated.
+        """
+        prefix = get_object_or_404(Prefix, pk=pk)
+
+        # Determine the maximum amount of IPs to return
+        try:
+            limit = int(request.query_params.get('limit', settings.PAGINATE_COUNT))
+        except ValueError:
+            limit = settings.PAGINATE_COUNT
+        if settings.MAX_PAGE_SIZE:
+            limit = min(limit, settings.MAX_PAGE_SIZE)
+
+        # Calculate available IPs within the prefix
+        ip_list = list(prefix.get_available_ips())[:limit]
+        serializer = serializers.AvailableIPSerializer(ip_list, many=True, context={
+            'request': request,
+            'prefix': prefix.prefix,
+            'vrf': prefix.vrf,
+        })
+
+        return Response(serializer.data)
+
 
 #
 # IP addresses