add Zone File source, reads Bind compatible zone files

tests/test_octodns_source_axfr.py

@@ -11,14 +11,15 @@ from dns.exception import DNSException
 from mock import patch
 from unittest import TestCase
 
-from octodns.source.axfr import AxfrSource, AxfrSourceZoneTransferFailed
+from octodns.source.axfr import AxfrSource, AxfrSourceZoneTransferFailed, \
+    ZoneFileSource, ZoneFileSourceLoadFailure
 from octodns.zone import Zone
 
 
 class TestAxfrSource(TestCase):
     source = AxfrSource('test', 'localhost')
 
-    forward_zonefile = dns.zone.from_file('./tests/zones/unit.tests.db',
+    forward_zonefile = dns.zone.from_file('./tests/zones/unit.tests.',
                                           'unit.tests', relativize=False)
 
     @patch('dns.zone.from_xfr')
@@ -38,3 +39,33 @@ class TestAxfrSource(TestCase):
             self.source.populate(zone)
         self.assertEquals('Unable to Perform Zone Transfer',
                           ctx.exception.message)
+
+
+class TestZoneFileSource(TestCase):
+    source = ZoneFileSource('test', './tests/zones')
+
+    def test_populate(self):
+        # Valid zone file in directory
+        valid = Zone('unit.tests.', [])
+        self.source.populate(valid)
+        self.assertEquals(11, len(valid.records))
+
+        # 2nd populate does not read file again
+        again = Zone('unit.tests.', [])
+        self.source.populate(again)
+        self.assertEquals(11, len(again.records))
+
+        # bust the cache
+        del self.source._zone_records[valid.name]
+
+        # No zone file in directory
+        missing = Zone('missing.zone.', [])
+        self.source.populate(missing)
+        self.assertEquals(0, len(missing.records))
+
+        # Zone file is not valid
+        with self.assertRaises(ZoneFileSourceLoadFailure) as ctx:
+            zone = Zone('invalid.zone.', [])
+            self.source.populate(zone)
+        self.assertEquals('The DNS zone has no NS RRset at its origin.',
+                          ctx.exception.message)