Handle Server-Timing headers manually (#143)

Author: pglombardo

instana/http_propagator.py

@@ -25,20 +25,16 @@ class HTTPPropagator():
     HEADER_KEY_T = 'X-Instana-T'
     HEADER_KEY_S = 'X-Instana-S'
     HEADER_KEY_L = 'X-Instana-L'
-    HEADER_KEY_ST = 'Server-Timing'
     LC_HEADER_KEY_T = 'x-instana-t'
     LC_HEADER_KEY_S = 'x-instana-s'
     LC_HEADER_KEY_L = 'x-instana-l'
-    LC_HEADER_KEY_ST = 'server-timing'
 
     ALT_HEADER_KEY_T = 'HTTP_X_INSTANA_T'
     ALT_HEADER_KEY_S = 'HTTP_X_INSTANA_S'
     ALT_HEADER_KEY_L = 'HTTP_X_INSTANA_L'
-    ATL_HEADER_KEY_ST = 'HTTP_SERVER_TIMING'
     ALT_LC_HEADER_KEY_T = 'http_x_instana_t'
     ALT_LC_HEADER_KEY_S = 'http_x_instana_s'
     ALT_LC_HEADER_KEY_L = 'http_x_instana_l'
-    ATL_LC_HEADER_KEY_ST = 'http_server_timing'
 
     def inject(self, span_context, carrier):
         try:
@@ -49,17 +45,14 @@ def inject(self, span_context, carrier):
                 carrier[self.HEADER_KEY_T] = trace_id
                 carrier[self.HEADER_KEY_S] = span_id
                 carrier[self.HEADER_KEY_L] = "1"
-                carrier[self.HEADER_KEY_ST] = "intid;desc=%s" % trace_id
             elif type(carrier) is list:
                 carrier.append((self.HEADER_KEY_T, trace_id))
                 carrier.append((self.HEADER_KEY_S, span_id))
                 carrier.append((self.HEADER_KEY_L, "1"))
-                carrier.append((self.HEADER_KEY_ST, "intid;desc=%s" % trace_id))
             elif hasattr(carrier, '__setitem__'):
                 carrier.__setitem__(self.HEADER_KEY_T, trace_id)
                 carrier.__setitem__(self.HEADER_KEY_S, span_id)
                 carrier.__setitem__(self.HEADER_KEY_L, "1")
-                carrier.__setitem__(self.HEADER_KEY_ST, "intid;desc=%s" % trace_id)
             else:
                 raise Exception("Unsupported carrier type", type(carrier))
 

instana/instrumentation/aiohttp/server.py

@@ -49,6 +49,7 @@ async def stan_middleware(request, handler):
 
                 scope.span.set_tag("http.status_code", response.status)
                 async_tracer.inject(scope.span.context, opentracing.Format.HTTP_HEADERS, response.headers)
+                response.headers['Server-Timing'] = "intid;desc=%s" % scope.span.context.trace_id
 
             return response
         except:

instana/instrumentation/django/middleware.py

@@ -60,6 +60,8 @@ def process_response(self, request, response):
 
                 request.iscope.span.set_tag(ext.HTTP_STATUS_CODE, response.status_code)
                 tracer.inject(request.iscope.span.context, ot.Format.HTTP_HEADERS, response)
+                response['Server-Timing'] = "intid;desc=%s" % request.iscope.span.context.trace_id
+
         except Exception:
             logger.debug("Instana middleware @ process_response", exc_info=True)
         finally:

instana/wsgi.py

@@ -20,6 +20,8 @@ def __call__(self, environ, start_response):
         def new_start_response(status, headers, exc_info=None):
             """Modified start response with additional headers."""
             tracer.inject(self.scope.span.context, ot.Format.HTTP_HEADERS, headers)
+            headers.append(('Server-Timing', "intid;desc=%s" % self.scope.span.context.trace_id))
+
             res = start_response(status, headers, exc_info)
 
             sc = status.split(' ')[0]

tests/test_ot_propagators.py

@@ -35,9 +35,6 @@ def test_inject_with_dict():
     assert_equals(carrier['X-Instana-S'], span.context.span_id)
     assert 'X-Instana-L' in carrier
     assert_equals(carrier['X-Instana-L'], "1")
-    assert 'Server-Timing' in carrier
-    server_timing_value = "intid;desc=%s" % span.context.trace_id
-    assert_equals(carrier['Server-Timing'], server_timing_value)
 
 
 def test_inject_with_list():
@@ -51,8 +48,6 @@ def test_inject_with_list():
     assert ('X-Instana-T', span.context.trace_id) in carrier
     assert ('X-Instana-S', span.context.span_id) in carrier
     assert ('X-Instana-L', "1") in carrier
-    server_timing_value = "intid;desc=%s" % span.context.trace_id
-    assert ('Server-Timing', server_timing_value) in carrier
 
 
 def test_basic_extract():