Set http.server_name based on Host header

Author: Skeen

Diff for: ext/opentelemetry-ext-asgi/src/opentelemetry/ext/asgi/__init__.py

@@ -89,16 +89,18 @@ def collect_request_attributes(scope):
     result = {
         "component": scope.get("type"),
         "http.method": scope.get("method"),
-        "http.server_name": server[0],
         "http.scheme": scope.get("scheme"),
         "http.host": server_host,
         "host.port": port,
         "http.flavor": scope.get("http_version"),
         "http.target": scope.get("path"),
         "http.url": http_url,
     }
+    http_host_value = ",".join(get_header_from_scope(scope, "host"))
+    if http_host_value:
+        result['http.server_name'] = http_host_value
 
-    if "client" in scope:
+    if "client" in scope and scope["client"] is not None:
         result["net.peer.ip"] = scope.get("client")[0]
         result["net.peer.port"] = scope.get("client")[1]
 

Diff for: ext/opentelemetry-ext-asgi/tests/test_asgi_middleware.py

@@ -114,7 +114,6 @@ def validate_outputs(self, outputs, error=None, modifiers=None):
                 "attributes": {
                     "component": "http",
                     "http.method": "GET",
-                    "http.server_name": "127.0.0.1",
                     "http.scheme": "http",
                     "host.port": 80,
                     "http.host": "127.0.0.1",
@@ -174,7 +173,6 @@ def test_behavior_with_scope_server_as_none(self):
         """Test that middleware is ok when server is none in scope."""
         def update_expected_server(expected):
             expected[3]['attributes'].update({
-                'http.server_name': '0.0.0.0',
                 'http.host': '0.0.0.0',
                 'host.port': 80,
                 'http.url': 'http://0.0.0.0/'
@@ -187,6 +185,21 @@ def update_expected_server(expected):
         outputs = self.get_all_output()
         self.validate_outputs(outputs, modifiers=[update_expected_server])
 
+    def test_host_header(self):
+        """Test that middleware is ok when server is none in scope."""
+        hostname = b"server_name_1"
+        def update_expected_server(expected):
+            expected[3]['attributes'].update({
+                'http.server_name': hostname.decode('utf8')
+            })
+            return expected
+        self.scope["headers"].append([b'host', hostname])
+        app = otel_asgi.OpenTelemetryMiddleware(simple_asgi)
+        self.seed_app(app)
+        self.send_default_request()
+        outputs = self.get_all_output()
+        self.validate_outputs(outputs, modifiers=[update_expected_server])
+
 
 
 class TestAsgiAttributes(unittest.TestCase):
@@ -209,7 +222,6 @@ def test_request_attributes(self):
                 "http.url": "http://127.0.0.1/?foo=bar",
                 "host.port": 80,
                 "http.scheme": "http",
-                "http.server_name": "127.0.0.1",
                 "http.flavor": "1.0",
                 "net.peer.ip": "127.0.0.1",
                 "net.peer.port": 32767,