Validate numericness of ports in builder files.

You can't really goof this up using bin/swift-ring-builder, but if you
have code that uses swift.common.ring.RingBuilder directly, you can
stuff e.g. "6002" in where you mean 6002, resulting in some fairly
baffling failures. (Yes, I have done this.)

Change-Id: I87b7b7066b9ea2ce6f82255605da99cf0d283689

swift/common/ring/builder.py

@@ -335,7 +335,7 @@ class RingBuilder(object):
         :raises RingValidationError: problem was found with the ring.
         """
 
-        # "len" showed up in profling, so it's just computed once.
+        # "len" showed up in profiling, so it's just computed once.
         dev_len = len(self.devs)
         if sum(d['parts'] for d in self._iter_devs()) != \
                 self.parts * self.replicas:
@@ -360,6 +360,12 @@ class RingBuilder(object):
                         "to a device." %
                         (part, replica))
 
+        for dev in self._iter_devs():
+            if not isinstance(dev['port'], int):
+                raise exceptions.RingValidationError(
+                    "Device %d has port %r, which is not an integer." %
+                    (dev['id'], dev['port']))
+
         if stats:
             weight_of_one_part = self.weight_of_one_part()
             worst = 0

test/unit/common/ring/test_builder.py

@@ -615,6 +615,11 @@ class TestRingBuilder(unittest.TestCase):
         self.assertRaises(exceptions.RingValidationError, rb.validate)
         rb.devs[1]['parts'] += 1
 
+        # Test non-numeric port
+        rb.devs[1]['port'] = '10001'
+        self.assertRaises(exceptions.RingValidationError, rb.validate)
+        rb.devs[1]['port'] = 10001
+
         # Test partition on nonexistent device
         rb.pretend_min_part_hours_passed()
         orig_dev_id = rb._replica2part2dev[0][0]