Add profiling support to neutronclient

To be able to create profiling traces for Neutron, client should be
able to send special HTTP header that contains trace info.
This patch is also important to be able to make cross project
traces. (Typical case nova calls neutron via python client, if
profiler is initialized in nova, neutron client will add extra
header, that will be parsed by special osprofiler middleware in neutron
api.)

Closes-Bug: #1335640

Co-Authored-By: Roman Podoliaka <rpodolyaka@mirantis.com>
Change-Id: Ic11796889075b2a0e589b70398fc4d4ed6f3ef7c

neutronclient/client.py

@@ -24,12 +24,15 @@ import os
 import debtcollector.renames
 from keystoneauth1 import access
 from keystoneauth1 import adapter
+from oslo_utils import importutils
 import requests
 
 from neutronclient._i18n import _
 from neutronclient.common import exceptions
 from neutronclient.common import utils
 
+osprofiler_web = importutils.try_import("osprofiler.web")
+
 _logger = logging.getLogger(__name__)
 
 if os.environ.get('NEUTRONCLIENT_DEBUG'):
@@ -151,6 +154,10 @@ class HTTPClient(object):
             headers.setdefault('Content-Type', content_type)
 
         headers['User-Agent'] = USER_AGENT
+        # NOTE(dbelova): osprofiler_web.get_trace_id_headers does not add any
+        # headers in case if osprofiler is not initialized.
+        if osprofiler_web:
+            headers.update(osprofiler_web.get_trace_id_headers())
 
         resp = requests.request(
             method,
@@ -301,6 +308,10 @@ class SessionClient(adapter.Adapter):
 
         headers = kwargs.setdefault('headers', {})
         headers.setdefault('Accept', content_type)
+        # NOTE(dbelova): osprofiler_web.get_trace_id_headers does not add any
+        # headers in case if osprofiler is not initialized.
+        if osprofiler_web:
+            headers.update(osprofiler_web.get_trace_id_headers())
 
         try:
             kwargs.setdefault('data', kwargs.pop('body'))

neutronclient/tests/unit/test_http.py

@@ -15,6 +15,8 @@
 
 import abc
 
+import osprofiler.profiler
+import osprofiler.web
 from requests_mock.contrib import fixture as mock_fixture
 import six
 import testtools
@@ -72,6 +74,14 @@ class TestHTTPClientMixin(object):
                    'Content-Type': 'application/json'}
         self._test_headers(headers, body=BODY, headers=headers)
 
+    def test_osprofiler_headers_are_injected(self):
+        osprofiler.profiler.init('SWORDFISH')
+        self.addCleanup(osprofiler.profiler._clean)
+
+        headers = {'Accept': 'application/json'}
+        headers.update(osprofiler.web.get_trace_id_headers())
+        self._test_headers(headers)
+
 
 class TestHTTPClient(TestHTTPClientMixin, testtools.TestCase):
 

releasenotes/notes/osprofiler-support-9ba539761ae437e9.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Add osprofiler support to the neutronclient python binding.
+    If osprofiler is initiated, neutronclient sends a special HTTP
+    header that contains trace info.

test-requirements.txt

@@ -9,6 +9,7 @@ mox3!=0.19.0,>=0.7.0 # Apache-2.0
 mock>=2.0 # BSD
 oslosphinx>=4.7.0 # Apache-2.0
 oslotest>=1.10.0 # Apache-2.0
+osprofiler>=1.4.0 # Apache-2.0
 python-openstackclient>=3.3.0 # Apache-2.0
 python-subunit>=0.0.18 # Apache-2.0/BSD
 reno>=1.8.0 # Apache-2.0