Add endpoint and cron job to aggregate all dimensions and values

appengine/swarming/handlers_endpoints_test.py

Index: appengine/swarming/handlers_endpoints_test.py
diff --git a/appengine/swarming/handlers_endpoints_test.py b/appengine/swarming/handlers_endpoints_test.py
index 14e13b99905637dc82b2ad58a1a67a624114c98e..cc950c3dc893eef422e105deb5d75183c987a5aa 100755
--- a/appengine/swarming/handlers_endpoints_test.py
+++ b/appengine/swarming/handlers_endpoints_test.py
@@ -1491,6 +1491,38 @@ class BotsApiTest(BaseTest):
     request = swarming_rpcs.BotsRequest(dimensions=['bad'])
     self.call_api('count', body=message_to_dict(request), status=400)
 
+  def test_dimensions_ok(self):
+    """Asserts that BotsDimensions is returned with the right data."""
+    self.set_as_privileged_user()
+    self.mock_now(datetime.datetime(2009, 1, 2, 3, 4, 5, 6))
+
+    aggregate = bot_management.DimensionAggregation(
+      id='current',

[M-A Ruel, 2016/08/05 14:36:05]

I'd prefer if you:
- simulate two bots polling with different dimensions
- ran the cron job explicitly

instead of lines 1499-1507, so more code would be exercised. Right now we don't
know if the cron job is broken and no way to test it via unit tests. Breakage
would be silent.

[kjlubick, 2016/08/05 17:38:58]

Done.  I kept this test as well as adding a new one.

+      dimensions=[
+        bot_management.DimensionValues(dimension='foo',
+          values=['alpha', 'beta']),
+        bot_management.DimensionValues(dimension='bar',
+          values=['gamma', 'delta', 'epsilon']),
+      ])
+    aggregate.put()
+
+    expected = {
+      u'fleet_dimensions': [
+        {
+          u'key': 'foo',
+          u'value': [u'alpha', u'beta'],
+        },
+        {
+          u'key': 'bar',
+          u'value': [u'gamma', u'delta', u'epsilon'],
+        },
+      ]
+    }
+
+    response = self.call_api('dimensions', body={})
+    self.assertEqual(expected, response.json)
+
+
 class BotApiTest(BaseTest):
   api_service_cls = handlers_endpoints.SwarmingBotService