feat(aiohttp): resolve full URL when ClientSession is initialized with base_url

ddtrace/contrib/internal/aiohttp/patch.py

@@ -1,4 +1,5 @@
 import os
+from typing import Optional
 
 import aiohttp
 import wrapt
@@ -83,7 +84,10 @@ async def _create_connection(self, req, *args, **kwargs):
 @with_traced_module
 async def _traced_clientsession_request(aiohttp, pin, func, instance, args, kwargs):
     method: str = get_argument_value(args, kwargs, 0, "method")
-    url: URL = URL(get_argument_value(args, kwargs, 1, "url"))
+    raw_url: URL = URL(str(get_argument_value(args, kwargs, 1, "url")))
+    # Resolve against base_url if present, mirroring aiohttp's internal behaviour.
+    base_url: Optional[URL] = getattr(instance, "_base_url", None)
+    url: URL = base_url.join(raw_url) if base_url is not None else raw_url
     params = kwargs.get("params")
     headers = kwargs.get("headers") or {}
 

releasenotes/notes/aiohttp-client-session-base-url-7109a5908dbddf58.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    aiohttp: Fixed an issue where spans captured an incomplete URL (e.g. ``/status/200``)
+    when ``aiohttp.ClientSession`` was initialized with a ``base_url``. The span now
+    records the fully-resolved URL (e.g. ``http://host:port/status/200``), matching
+    aiohttp's internal behaviour.

tests/contrib/aiohttp/test_aiohttp_client.py

@@ -225,3 +225,19 @@ async def test_trace_multiple(snapshot_context):
                 assert resp.status == 200
             async with session.get(URL_200) as resp:
                 assert resp.status == 200
+
+
+@pytest.mark.skipif(
+    tuple(int(x) for x in aiohttp.__version__.split(".")[:2]) < (3, 8),
+    reason="base_url parameter added in aiohttp 3.8.0",
+)
+@pytest.mark.asyncio
+async def test_base_url(snapshot_context):
+    """
+    When ClientSession is initialized with base_url
+        The full URL (base + path) is captured in the span
+    """
+    with snapshot_context():
+        async with aiohttp.ClientSession(base_url="http://{}".format(SOCKET)) as session:
+            async with session.get("/status/200") as resp:
+                assert resp.status == 200

tests/snapshots/tests.contrib.aiohttp.test_aiohttp_client.test_base_url.json

@@ -0,0 +1,48 @@
+[[
+  {
+    "name": "aiohttp.request",
+    "service": "tests.contrib.aiohttp",
+    "resource": "aiohttp.request",
+    "trace_id": 0,
+    "span_id": 1,
+    "parent_id": 0,
+    "type": "http",
+    "error": 0,
+    "meta": {
+      "_dd.p.dm": "-0",
+      "_dd.p.tid": "654a694400000000",
+      "component": "aiohttp_client",
+      "http.method": "GET",
+      "http.status_code": "200",
+      "http.status_msg": "OK",
+      "http.url": "http://localhost:8001/status/200",
+      "language": "python",
+      "out.host": "localhost",
+      "runtime-id": "de4fa08308ec4bc3a437ed78b9f99c47",
+      "span.kind": "client"
+    },
+    "metrics": {
+      "_dd.top_level": 1,
+      "_dd.tracer_kr": 1.0,
+      "_sampling_priority_v1": 1,
+      "process_id": 2189
+    },
+    "duration": 3943217,
+    "start": 1691160518131287373
+  },
+     {
+       "name": "TCPConnector.connect",
+       "service": "tests.contrib.aiohttp",
+       "resource": "TCPConnector.connect",
+       "trace_id": 0,
+       "span_id": 2,
+       "parent_id": 1,
+       "type": "",
+       "error": 0,
+       "meta": {
+         "_dd.p.tid": "654a694400000000",
+         "component": "aiohttp"
+       },
+       "duration": 2305283,
+       "start": 1691160518131963432
+     }]]