fix: prevent tracing internal requests.

This commit sets the HTTP headers with the tracing level as 0 to prevent our lib's internal requests from being traced when the INSTANA_ALLOW_EXIT_AS_ROOT environment variable is set.

Signed-off-by: Paulo Vital <paulo.vital@ibm.com>

src/instana/agent/aws_eks_fargate.py

@@ -66,6 +66,7 @@ def report_data_payload(self, payload):
                 self.report_headers["Content-Type"] = "application/json"
                 self.report_headers["X-Instana-Host"] = self.podname
                 self.report_headers["X-Instana-Key"] = self.options.agent_key
+                self.report_headers["X-Instana-L"] = "0"
 
             response = self.client.post(self.__data_bundle_url(),
                                         data=to_json(payload),

src/instana/agent/aws_fargate.py

@@ -63,6 +63,7 @@ def report_data_payload(self, payload):
                 self.report_headers["Content-Type"] = "application/json"
                 self.report_headers["X-Instana-Host"] = self.collector.get_fq_arn()
                 self.report_headers["X-Instana-Key"] = self.options.agent_key
+                self.report_headers["X-Instana-L"] = "0"
 
             response = self.client.post(self.__data_bundle_url(),
                                         data=to_json(payload),

src/instana/agent/aws_lambda.py

@@ -63,6 +63,7 @@ def report_data_payload(self, payload):
                 self.report_headers["Content-Type"] = "application/json"
                 self.report_headers["X-Instana-Host"] = self.collector.get_fq_arn()
                 self.report_headers["X-Instana-Key"] = self.options.agent_key
+                self.report_headers["X-Instana-L"] = "0"
 
             response = self.client.post(self.__data_bundle_url(),
                                         data=to_json(payload),

src/instana/agent/google_cloud_run.py

@@ -64,7 +64,8 @@ def report_data_payload(self, payload):
                     "Content-Type": "application/json",
                     "X-Instana-Host": "gcp:cloud-run:revision:{revision}".format(
                         revision=self.collector.revision),
-                    "X-Instana-Key": self.options.agent_key
+                    "X-Instana-Key": self.options.agent_key,
+                    "X-Instana-L": "0",
                 }
 
             response = self.client.post(self.__data_bundle_url(),

src/instana/agent/host.py

@@ -40,6 +40,10 @@ class HostAgent(BaseAgent):
     """
     AGENT_DISCOVERY_PATH = "com.instana.plugin.python.discovery"
     AGENT_DATA_PATH = "com.instana.plugin.python.%d"
+    AGENT_REQUEST_HEADERS = {
+        "Content-Type": "application/json",
+        "X-INSTANA-L": "0",
+    }
 
     def __init__(self):
         super(HostAgent, self).__init__()
@@ -154,7 +158,7 @@ def is_agent_listening(self, host, port):
         result = False
         try:
             url = "http://%s:%s/" % (host, port)
-            response = self.client.get(url, timeout=5)
+            response = self.client.get(url, timeout=5, headers={"X-INSTANA-L": "0"})
 
             if 200 <= response.status_code < 300:
                 logger.debug("Instana host agent found on %s:%d", host, port)
@@ -176,7 +180,7 @@ def announce(self, discovery):
             url = self.__discovery_url()
             response = self.client.put(url,
                                        data=to_json(discovery),
-                                       headers={"Content-Type": "application/json"},
+                                       headers=self.AGENT_REQUEST_HEADERS,
                                        timeout=0.8)
         except Exception as exc:
             logger.debug("announce: connection error (%s)", type(exc))
@@ -224,10 +228,11 @@ def log_message_to_host_agent(self, message):
             payload["m"] = message
 
             url = self.__agent_logger_url()
+            headers = self.AGENT_REQUEST_HEADERS
+            headers.update({"X-Log-Level": "INFO"})
             response = self.client.post(url,
                                        data=to_json(payload),
-                                       headers={"Content-Type": "application/json",
-                                                "X-Log-Level": "INFO"},
+                                       headers=headers,
                                        timeout=0.8)
 
             if 200 <= response.status_code <= 204:
@@ -241,7 +246,7 @@ def is_agent_ready(self):
         """
         ready = False
         try:
-            response = self.client.head(self.__data_url(), timeout=0.8)
+            response = self.client.head(self.__data_url(), timeout=0.8, headers={"X-INSTANA-L": "0"})
 
             if response.status_code == 200:
                 ready = True
@@ -261,7 +266,7 @@ def report_data_payload(self, payload):
                 logger.debug("Reporting %d spans", span_count)
                 response = self.client.post(self.__traces_url(),
                                             data=to_json(payload['spans']),
-                                            headers={"Content-Type": "application/json"},
+                                            headers=self.AGENT_REQUEST_HEADERS,
                                             timeout=0.8)
 
             if response is not None and 200 <= response.status_code <= 204:
@@ -273,7 +278,7 @@ def report_data_payload(self, payload):
                 logger.debug("Reporting %d profiles", profile_count)
                 response = self.client.post(self.__profiles_url(),
                                             data=to_json(payload['profiles']),
-                                            headers={"Content-Type": "application/json"},
+                                            headers=self.AGENT_REQUEST_HEADERS,
                                             timeout=0.8)
 
             if response is not None and 200 <= response.status_code <= 204:
@@ -283,7 +288,7 @@ def report_data_payload(self, payload):
             metric_bundle = payload["metrics"]["plugins"][0]["data"]
             response = self.client.post(self.__data_url(),
                                         data=to_json(metric_bundle),
-                                        headers={"Content-Type": "application/json"},
+                                        headers=self.AGENT_REQUEST_HEADERS,
                                         timeout=0.8)
 
             if response is not None and 200 <= response.status_code <= 204:
@@ -377,7 +382,7 @@ def __task_response(self, message_id, data):
 
             response = self.client.post(self.__response_url(message_id),
                                         data=payload,
-                                        headers={"Content-Type": "application/json"},
+                                        headers=self.AGENT_REQUEST_HEADERS,
                                         timeout=0.8)
         except Exception as exc:
             logger.debug("__task_response: Instana host agent connection error (%s)", type(exc))

tests/platforms/test_host.py

@@ -234,6 +234,38 @@ def test_announce_fails_with_missing_uuid(self, mock_requests_session_put):
         self.assertEqual(len(log.records), 1)
         self.assertIn('response payload has no agentUuid', log.output[0])
 
+    @patch.object(requests.Session, "put")
+    def test_announce_is_suppressed(self, mock_requests_session_put):
+        test_pid = 4242
+        test_process_name = 'test_process'
+        test_process_args = ['-v', '-d']
+        test_agent_uuid = '83bf1e09-ab16-4203-abf5-34ee0977023a'
+
+        mock_response = MagicMock()
+        mock_response.status_code = 200
+        mock_response.content = (
+                '{'
+                f'  "pid": {test_pid}, '
+                f'  "agentUuid": "{test_agent_uuid}"'
+                '}')
+
+        # This mocks the call to self.agent.client.put
+        mock_requests_session_put.return_value = mock_response
+
+        self.create_agent_and_setup_tracer()
+        d = Discovery(
+            pid=test_pid,
+            name=test_process_name, 
+            args=test_process_args
+        )
+        payload = self.agent.announce(d)
+
+        self.assertIn('pid', payload)
+        self.assertEqual(test_pid, payload['pid'])
+
+        spans = self.span_recorder.queued_spans()
+        self.assertEqual(len(spans), 0)
+
 
     @patch.object(requests.Session, "get")
     def test_agent_connection_attempt(self, mock_requests_session_get):