Sporadic integration test failures during artifact uploads.

Failed	tests/test_grouping.py::TestGrouping::()::test_update_device_group	61.83	URL
[gw4] linux2 -- Python 2.7.12 /usr/bin/python

self = <tests.test_grouping.TestGrouping object at 0x7f80735edd10>

    def test_update_device_group(self):
        """
                Perform a successful upgrade on one group of devices, and assert that:
                * deployment status/logs are correct.
                * only the correct group is updated, not the other one.
    
                A reboot is performed, and running partitions have been swapped.
                Deployment status will be set as successful for device.
                Logs will not be retrieved, and result in 404.
            """
    
        # Beware that there will two parallel things going on below, one for
        # each group, hence a lot of separate execute() calls for each. We aim
        # to update the group alpha, not beta.
    
        clients = get_mender_clients()
        assert(len(clients) == 2)
        alpha = clients[0]
        bravo = clients[1]
    
        ip_to_device_id = Helpers.ip_to_device_id_map(clients)
        id_alpha = ip_to_device_id[alpha]
        id_bravo = ip_to_device_id[bravo]
        print("ID of alpha host: %s\nID of bravo host: %s" % (id_alpha, id_bravo))
    
        ret = execute(Helpers.get_passive_partition, hosts=clients)
        pass_part_alpha = ret[alpha]
        pass_part_bravo = ret[bravo]
    
        inv.put_device_in_group(id_alpha, "Update")
    
        reboot = { alpha: None, bravo: None }
        with Helpers.RebootDetector(alpha) as reboot[alpha], Helpers.RebootDetector(bravo) as reboot[bravo]:
    
            deployment_id, expected_image_id = common_update_procedure(conftest.get_valid_image(),
>                                                                      devices=[id_alpha])

tests/test_grouping.py:128: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
tests/common_update.py:54: in common_update_procedure
    deploy.upload_image(created_artifact)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <MenderAPI.deployments.Deployments object at 0x7f8073781610>
filename = '/tmp/tmpuHYPev', description = 'abc'

    def upload_image(self, filename, description="abc"):
        image_path_url = self.get_deployments_base_path() + "artifacts"
    
        r = requests.post(image_path_url,
                          verify=False,
                          headers=self.auth.get_auth_token(),
                          files=(
                              ("description", (None, description)),
                              ("size", (None, str(os.path.getsize(filename)))),
                              ("artifact", (filename, open(filename), "application/octet-stream"))
                          ))
    
        logger.info("Received image upload status code: " + str(r.status_code) + " with payload: " + str(r.text))
>       assert r.status_code == requests.status_codes.codes.created
E       AssertionError

MenderAPI/deployments.py:49: AssertionError
------------------------------ Captured log setup ------------------------------
filelock.py                276 INFO     Lock 140189746105296 acquired on docker_lock
filelock.py                320 INFO     Lock 140189746105296 released on docker_lock
filelock.py                276 INFO     Lock 140189746105296 acquired on docker_lock
filelock.py                276 INFO     Lock 140189746105296 acquired on docker_lock
filelock.py                320 INFO     Lock 140189746105296 released on docker_lock
filelock.py                276 INFO     Lock 140189746105296 acquired on docker_lock
filelock.py                320 INFO     Lock 140189746105296 released on docker_lock
filelock.py                276 INFO     Lock 140189746105296 acquired on docker_lock
filelock.py                320 INFO     Lock 140189746105296 released on docker_lock
authentication.py           82 INFO     Using Authorization headers: eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE1MzkwMTY0ODIsImp0aSI6IjFmY2Q4ODQ5LTMxMDMtNDFkZi1iOTY1LTlhODYwMDJiYjVjZSIsImlzcyI6Im1lbmRlci51c2VyYWRtIiwic3ViIjoiMTBjMTNiZWEtMTcwNi00Yjk1LThlODktMDA1MTVmNDk1ZWY2Iiwic2NwIjoibWVuZGVyLioiLCJtZW5kZXIudXNlciI6dHJ1ZX0.dw6b16zC3ztqOpixf4mlxmOjoQUWXrhfrjL235BFwLEzAH7IxZA2q9TKecciUV3vtKWBdrEXKyCsmVuHgzait8U828nMb3yrCjaApWJ24fE3F7QsL9oZgbPPxZHZUiexCCilfk82UM_EyGTVSmQZMU3mQUE1JSjvBvqFdOXSNIlw5zG9fW-E1Ganx_ZmLsfk5zD04I7_ApmInV9ZckvLYK58PFo-Tjpdoj6F_hLRCGtWLjejyDJXw1DlU0Afney-hIig27V9MNGs0dLeoprLDLfZ6XIOsz-kE1MJ7KJyO9M31eOOhu9L_nhDZVjGvS52vx0FEsu7hSb622pS8QCJr1b5T5ozoT7xZ8V-Tf4hu8b6NIBADshC4-5ToTDQcZN1jq-7wFcnFTBhCIV86oOriSwGbkUnP25ne6QCZzoa1mhGJh3luJXMBc1pNjPONeRP87HbCvuwwrdCp4UdSWRIl4Y9fcUZBwwSqfL7L9sZNHH-AerTEdGf-1-bHWkkRt_Q------------------------------ Captured log call -------------------------------
filelock.py                276 INFO     Lock 140189670181584 acquired on .artifact_modification_lock
filelock.py                320 INFO     Lock 140189670181584 released on .artifact_modification_lock