pass X-Debug header downstream

talisker/requests.py

@@ -72,6 +72,7 @@
 STORAGE = Local()
 STORAGE.sessions = {}
 HOSTS = module_dict()
+DEBUG_HEADER = future.utils.text_to_native_str('X-Debug')
 
 
 def clear():
@@ -169,6 +170,8 @@ def send(request, **kwargs):
             deadline = datetime.utcfromtimestamp(Context.current.deadline)
             formatted = deadline.isoformat() + 'Z'
             request.headers[config.deadline_header] = formatted
+        if Context.debug:
+            request.headers[DEBUG_HEADER] = '1'
         try:
             return func(request, **kwargs)
         except Exception as e:

tests/test_requests.py

@@ -223,6 +223,7 @@ def test_metric_hook_registered_endpoint(
 def test_configured_session(context, get_breadcrumbs):
     deadline = time.time() + 10
     expected_deadline = datetime.utcfromtimestamp(deadline).isoformat() + 'Z'
+    Context.set_debug()
     Context.current.deadline = deadline
     session = requests.Session()
     talisker.requests.configure(session)
@@ -242,6 +243,7 @@ def test_configured_session(context, get_breadcrumbs):
     headers = responses.calls[0].request.headers
     assert headers['X-Request-Id'] == 'XXX'
     assert headers['X-Request-Deadline'] == expected_deadline
+    assert headers['X-Debug'] == '1'
     assert context.statsd[0] == 'requests.count.localhost.view:1|c'
     assert context.statsd[1].startswith(
         'requests.latency.localhost.view.200:')