Merge pull request #1534 from coreos-inc/flakey-test

Fix flaky tests

test/registry_tests.py

@@ -314,6 +314,9 @@ class BaseRegistryMixin(object):
 
     response = self.session.request(method, self.get_server_url() + url, headers=headers, data=data,
                                     auth=auth_tuple, params=params)
+    if expected_code is None:
+      return response
+
     if response.status_code != expected_code:
       print response.text
 
@@ -1503,10 +1506,20 @@ class ACIConversionTests(RegistryTestCaseMixin, V1RegistryPushMixin, LiveServerT
     return tar, response.content
 
   def get_converted_signature(self):
-    # Give time for the signature to be written before continuing.
-    time.sleep(2)
-    response = self.conduct('GET', '/c1/aci/localhost:5000/devtable/newrepo/latest/aci.asc/linux/amd64/', auth='sig')
-    return response.content
+    counter = 0
+
+    # Give time for the signature to be written before continuing. As we don't exactly know when
+    # this is (based on CPU conditions when the test is being run), we try a backoff and sleep
+    # approach.
+    while counter < 5:
+      response = self.conduct('GET', '/c1/aci/localhost:5000/devtable/newrepo/latest/aci.asc/linux/amd64/', auth='sig', expected_code=None)
+      if response.status_code == 202 or response.status_code == 404:
+        counter += 1
+        time.sleep(counter * 2)
+      else:
+        return response.content
+
+    self.fail('Signature was never created')
 
   def _verify_signature(self, signature, converted):
     sig_bytes = StringIO(signature)