Merge "Treat ec2 collector data as immutable"

os_collect_config/ec2.py

@@ -13,9 +13,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
+import os
+
 from oslo_config import cfg
 from oslo_log import log
 
+from os_collect_config import cache
 from os_collect_config import common
 from os_collect_config import exc
 
@@ -60,5 +64,11 @@ class Collector(object):
         return content
 
     def collect(self):
+        cache_path = cache.get_path('ec2')
+        if os.path.exists(cache_path):
+            with open(cache_path) as f:
+                metadata = json.load(f)
+                if metadata:
+                    return [('ec2', metadata)]
         root_url = '%s/' % (CONF.ec2.metadata_url)
         return [('ec2', self._fetch_metadata(root_url, CONF.ec2.timeout))]

os_collect_config/tests/test_collect.py

@@ -476,9 +476,16 @@ class TestCollectAll(testtools.TestCase):
         # Commit
         for changed in changed_keys:
             cache.commit(changed)
+
+        # Replace the ec2 requests with a failing one to simulate a transient
+        # network failure
+        soft_config_map['ec2'] = {'requests_impl': test_ec2.FakeFailRequests}
         (changed_keys, paths2) = self._call_collect_all(
             store=True, collector_kwargs_map=soft_config_map)
         self.assertEqual(set(), changed_keys)
+
+        # check the second collect includes cached ec2 data despite network
+        # failure
         self.assertEqual(paths, paths2)
 
     def test_collect_all_nostore(self):

os_collect_config/tests/test_ec2.py

@@ -13,9 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
+import os
 import uuid
 
 import fixtures
+from oslo_config import cfg
 import requests
 import six.moves.urllib.parse as urlparse
 import testtools
@@ -114,3 +117,15 @@ class TestEc2(testtools.TestCase):
         collect_ec2 = ec2.Collector(requests_impl=FakeFailRequests)
         self.assertRaises(exc.Ec2MetadataNotAvailable, collect_ec2.collect)
         self.assertIn('Forbidden', self.log.output)
+
+    def test_collect_ec2_collected(self):
+        collect.setup_conf()
+        cache_dir = self.useFixture(fixtures.TempDir())
+        self.addCleanup(cfg.CONF.reset)
+        cfg.CONF.set_override('cachedir', cache_dir.path)
+        ec2_path = os.path.join(cache_dir.path, 'ec2.json')
+        with open(ec2_path, 'w') as f:
+            json.dump(META_DATA, f)
+
+        collect_ec2 = ec2.Collector(requests_impl=FakeFailRequests)
+        self.assertEqual([('ec2', META_DATA)], collect_ec2.collect())