diff options
| -rw-r--r-- | cloudinit/sources/DataSourceAzure.py | 18 | ||||
| -rw-r--r-- | cloudinit/tests/test_url_helper.py | 25 | ||||
| -rw-r--r-- | cloudinit/url_helper.py | 14 | ||||
| -rw-r--r-- | tests/unittests/test_datasource/test_azure.py | 30 |
4 files changed, 71 insertions, 16 deletions
diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py index 6e1797ea..9e8a1a8b 100644 --- a/cloudinit/sources/DataSourceAzure.py +++ b/cloudinit/sources/DataSourceAzure.py @@ -22,7 +22,7 @@ from cloudinit.event import EventType from cloudinit.net.dhcp import EphemeralDHCPv4 from cloudinit import sources from cloudinit.sources.helpers.azure import get_metadata_from_fabric -from cloudinit.url_helper import readurl, UrlError +from cloudinit.url_helper import UrlError, readurl, retry_on_url_exc from cloudinit import util LOG = logging.getLogger(__name__) @@ -526,13 +526,6 @@ class DataSourceAzure(sources.DataSource): report_ready = bool(not os.path.isfile(REPORTED_READY_MARKER_FILE)) LOG.debug("Start polling IMDS") - def exc_cb(msg, exception): - if isinstance(exception, UrlError) and exception.code == 404: - return True - # If we get an exception while trying to call IMDS, we - # call DHCP and setup the ephemeral network to acquire the new IP. - return False - while True: try: # Save our EphemeralDHCPv4 context so we avoid repeated dhcp @@ -547,7 +540,7 @@ class DataSourceAzure(sources.DataSource): self._report_ready(lease=lease) report_ready = False return readurl(url, timeout=1, headers=headers, - exception_cb=exc_cb, infinite=True, + exception_cb=retry_on_url_exc, infinite=True, log_req_resp=False).contents except UrlError: # Teardown our EphemeralDHCPv4 context on failure as we retry @@ -1187,17 +1180,12 @@ def get_metadata_from_imds(fallback_nic, retries): def _get_metadata_from_imds(retries): - def retry_on_url_error(msg, exception): - if isinstance(exception, UrlError) and exception.code == 404: - return True # Continue retries - return False # Stop retries on all other exceptions - url = IMDS_URL + "instance?api-version=2017-12-01" headers = {"Metadata": "true"} try: response = readurl( url, timeout=1, headers=headers, retries=retries, - exception_cb=retry_on_url_error) + exception_cb=retry_on_url_exc) except Exception as e: LOG.debug('Ignoring IMDS instance metadata: %s', e) return {} diff --git a/cloudinit/tests/test_url_helper.py b/cloudinit/tests/test_url_helper.py index 113249d9..aa9f3ec1 100644 --- a/cloudinit/tests/test_url_helper.py +++ b/cloudinit/tests/test_url_helper.py @@ -1,10 +1,12 @@ # This file is part of cloud-init. See LICENSE file for license information. -from cloudinit.url_helper import oauth_headers, read_file_or_url +from cloudinit.url_helper import ( + NOT_FOUND, UrlError, oauth_headers, read_file_or_url, retry_on_url_exc) from cloudinit.tests.helpers import CiTestCase, mock, skipIf from cloudinit import util import httpretty +import requests try: @@ -64,3 +66,24 @@ class TestReadFileOrUrl(CiTestCase): result = read_file_or_url(url) self.assertEqual(result.contents, data) self.assertEqual(str(result), data.decode('utf-8')) + + +class TestRetryOnUrlExc(CiTestCase): + + def test_do_not_retry_non_urlerror(self): + """When exception is not UrlError return False.""" + myerror = IOError('something unexcpected') + self.assertFalse(retry_on_url_exc(msg='', exc=myerror)) + + def test_perform_retries_on_not_found(self): + """When exception is UrlError with a 404 status code return True.""" + myerror = UrlError(cause=RuntimeError( + 'something was not found'), code=NOT_FOUND) + self.assertTrue(retry_on_url_exc(msg='', exc=myerror)) + + def test_perform_retries_on_timeout(self): + """When exception is a requests.Timout return True.""" + myerror = UrlError(cause=requests.Timeout('something timed out')) + self.assertTrue(retry_on_url_exc(msg='', exc=myerror)) + +# vi: ts=4 expandtab diff --git a/cloudinit/url_helper.py b/cloudinit/url_helper.py index cf57dbd5..396d69ae 100644 --- a/cloudinit/url_helper.py +++ b/cloudinit/url_helper.py @@ -554,4 +554,18 @@ def oauth_headers(url, consumer_key, token_key, token_secret, consumer_secret, _uri, signed_headers, _body = client.sign(url) return signed_headers + +def retry_on_url_exc(msg, exc): + """readurl exception_cb that will retry on NOT_FOUND and Timeout. + + Returns False to raise the exception from readurl, True to retry. + """ + if not isinstance(exc, UrlError): + return False + if exc.code == NOT_FOUND: + return True + if exc.cause and isinstance(exc.cause, requests.Timeout): + return True + return False + # vi: ts=4 expandtab diff --git a/tests/unittests/test_datasource/test_azure.py b/tests/unittests/test_datasource/test_azure.py index 8ad4368c..56484b27 100644 --- a/tests/unittests/test_datasource/test_azure.py +++ b/tests/unittests/test_datasource/test_azure.py @@ -17,6 +17,7 @@ import crypt import httpretty import json import os +import requests import stat import xml.etree.ElementTree as ET import yaml @@ -184,6 +185,35 @@ class TestGetMetadataFromIMDS(HttprettyTestCase): "Crawl of Azure Instance Metadata Service (IMDS) took", # log_time self.logs.getvalue()) + @mock.patch('requests.Session.request') + @mock.patch('cloudinit.url_helper.time.sleep') + @mock.patch(MOCKPATH + 'net.is_up') + def test_get_metadata_from_imds_retries_on_timeout( + self, m_net_is_up, m_sleep, m_request): + """Retry IMDS network metadata on timeout errors.""" + + self.attempt = 0 + m_request.side_effect = requests.Timeout('Fake Connection Timeout') + + def retry_callback(request, uri, headers): + self.attempt += 1 + raise requests.Timeout('Fake connection timeout') + + httpretty.register_uri( + httpretty.GET, + dsaz.IMDS_URL + 'instance?api-version=2017-12-01', + body=retry_callback) + + m_net_is_up.return_value = True # skips dhcp + + self.assertEqual({}, dsaz.get_metadata_from_imds('eth9', retries=3)) + + m_net_is_up.assert_called_with('eth9') + self.assertEqual([mock.call(1)]*3, m_sleep.call_args_list) + self.assertIn( + "Crawl of Azure Instance Metadata Service (IMDS) took", # log_time + self.logs.getvalue()) + class TestAzureDataSource(CiTestCase): |