fix(ingress-nginx): filter out healthcheck traces

src/tracing_library.cpp

@@ -119,6 +119,17 @@ dd::Expected<dd::Tracer> TracingLibrary::make_tracer(
                     .resource = "GET /is-dynamic-lb-initialized",
                     .tags = {}},
             .mechanism = datadog::tracing::SamplingMechanism::RULE});
+
+    // TODO(@dmehala): Disable tracing if `stub_status on;`.
+    final_config->trace_sampler.rules.emplace_back(
+        datadog::tracing::TraceSamplerRule{
+            .rate = datadog::tracing::Rate::zero(),
+            .matcher =
+                datadog::tracing::SpanMatcher{.service = "*",
+                                              .name = "*",
+                                              .resource = "GET /nginx_status",
+                                              .tags = {}},
+            .mechanism = datadog::tracing::SamplingMechanism::RULE});
   }
 
   if (!final_config) {

test/cases/ingress-nginx/conf/main.conf

@@ -21,5 +21,9 @@ http {
         location /is-dynamic-lb-initialized {
             proxy_pass http://http:8080;
         }
+
+        location /nginx_status {
+            proxy_pass http://http:8080;
+        }
     }
 }

test/cases/ingress-nginx/test_rules.py

@@ -35,3 +35,26 @@ def test_healthcheck(self):
         response = json.loads(body)
         self.assertEqual(response["headers"]["x-datadog-sampling-priority"],
                          "1")
+
+    def test_healthcheck_stubstatus(self):
+        # Healthcheck request MUST not be generated traces.
+        conf_path = Path(__file__).parent / "conf" / "main.conf"
+        conf_text = conf_path.read_text()
+
+        status, log_lines = self.orch.nginx_replace_config(
+            conf_text, conf_path.name)
+        self.assertEqual(status, 0, log_lines)
+
+        status, _, body = self.orch.send_nginx_http_request("/nginx_status")
+        self.assertEqual(status, 200)
+
+        response = json.loads(body)
+        self.assertEqual(response["headers"]["x-datadog-sampling-priority"],
+                         "-1")
+
+        status, _, body = self.orch.send_nginx_http_request("/")
+        self.assertEqual(status, 200)
+
+        response = json.loads(body)
+        self.assertEqual(response["headers"]["x-datadog-sampling-priority"],
+                         "1")

test/cases/opentelemetry/test_otel_drop_in_support.py

@@ -137,6 +137,13 @@ def test_directives(self):
                 "service": "*",
                 "tags": {},
             })
+            rules.append({
+                "name": "*",
+                "resource": "GET /nginx_status",
+                "sample_rate": 0.0,
+                "service": "*",
+                "tags": {},
+            })
 
         pattern = {
             "service": "foo",