Optionally make dynamic vendordata failures fatal.

Some operators would like instance starts to fail if we cannot
fetch dynamic vendordata. Add an option to do that.

Change-Id: I0c31465c5c52cd4c7e4bb229a4452bc4c8df0e88

nova/api/metadata/vendordata_dynamic.py

@@ -16,6 +16,8 @@
 """Render vendordata as stored fetched from REST microservices."""
 
 import requests
+import six
+import sys
 
 from keystoneauth1 import exceptions as ks_exceptions
 from keystoneauth1 import loading as ks_loading
@@ -111,6 +113,9 @@ class DynamicVendorData(vendordata.VendorDataDriver):
                          'url': url,
                          'error': e},
                         instance=self.instance)
+            if CONF.api.vendordata_dynamic_failure_fatal:
+                six.reraise(type(e), e, sys.exc_info()[2])
+
             return {}
 
     def get(self):

nova/conf/api.py

@@ -103,6 +103,7 @@ Related options:
 * vendordata_dynamic_ssl_certfile
 * vendordata_dynamic_connect_timeout
 * vendordata_dynamic_read_timeout
+* vendordata_dynamic_failure_fatal
 """),
     cfg.ListOpt('vendordata_dynamic_targets',
         default=[],
@@ -132,6 +133,7 @@ Related options:
 * vendordata_dynamic_targets
 * vendordata_dynamic_connect_timeout
 * vendordata_dynamic_read_timeout
+* vendordata_dynamic_failure_fatal
 """),
     cfg.IntOpt('vendordata_dynamic_connect_timeout',
         default=5,
@@ -152,6 +154,7 @@ Related options:
 * vendordata_dynamic_targets
 * vendordata_dynamic_ssl_certfile
 * vendordata_dynamic_read_timeout
+* vendordata_dynamic_failure_fatal
 """),
     cfg.IntOpt('vendordata_dynamic_read_timeout',
         default=5,
@@ -171,6 +174,20 @@ Related options:
 * vendordata_dynamic_targets
 * vendordata_dynamic_ssl_certfile
 * vendordata_dynamic_connect_timeout
+* vendordata_dynamic_failure_fatal
+"""),
+    cfg.BoolOpt('vendordata_dynamic_failure_fatal',
+        default=False,
+        help="""
+Should failures to fetch dynamic vendordata be fatal to instance boot?
+
+Related options:
+
+* vendordata_providers
+* vendordata_dynamic_targets
+* vendordata_dynamic_ssl_certfile
+* vendordata_dynamic_connect_timeout
+* vendordata_dynamic_read_timeout
 """),
     cfg.IntOpt("metadata_cache_expiration",
         default=15,

nova/tests/unit/test_metadata.py

@@ -949,6 +949,16 @@ class OpenStackMetadataTestCase(test.TestCase):
         self._test_vendordata2_response_inner_exceptional(
                 request_mock, log_mock, ks_exceptions.SSLError)
 
+    @mock.patch.object(vendordata_dynamic.LOG, 'warning')
+    @mock.patch.object(session.Session, 'request')
+    def test_vendor_data_response_vendordata2_ssl_error_fatal(self,
+                                                              request_mock,
+                                                              log_mock):
+        self.flags(vendordata_dynamic_failure_fatal=True, group='api')
+        self.assertRaises(ks_exceptions.SSLError,
+                          self._test_vendordata2_response_inner_exceptional,
+                          request_mock, log_mock, ks_exceptions.SSLError)
+
     def test_network_data_presence(self):
         inst = self.instance.obj_clone()
         mdinst = fake_InstanceMetadata(self, inst)

releasenotes/notes/vendordata-reboot-hard-failure-42beeb1044680a50.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    The vendordata metadata system now supports a hard failure mode. This can
+    be enabled using the ``api.vendordata_dynamic_failure_fatal`` configuration
+    option.  When enabled, an instance will fail to start if the instance
+    cannot fetch dynamic vendordata.