Capture full URL in urllib3 spans

Spotted whilst debugging a customer's traces.

Author: adamchainz

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Pending
+
+### Fixed
+
+- Capture the full URL in `urllib3` spans.
+
 ## [2.16.2] 2020-09-17
 
 - Moved core agent on Linux to default to the musl version, rather than try

src/scout_apm/instruments/urllib3.py

@@ -43,21 +43,22 @@ def ensure_installed():
 
 @wrapt.decorator
 def wrapped_urlopen(wrapped, instance, args, kwargs):
-    def _extract_method(method, *args, **kwargs):
-        return method
+    def _extract_method_url(method, url, *args, **kwargs):
+        return method, url
 
     try:
-        method = _extract_method(*args, **kwargs)
+        method, url = _extract_method_url(*args, **kwargs)
     except TypeError:
         method = "Unknown"
-
-    try:
-        url = text_type(instance._absolute_url("/"))
-    except Exception:
-        logger.exception("Could not get URL for HTTPConnectionPool")
         url = "Unknown"
+    else:
+        try:
+            url = text_type(instance._absolute_url(url))
+        except Exception:
+            logger.exception("Could not get URL for HTTPConnectionPool")
+            url = "Unknown"
 
     tracked_request = TrackedRequest.instance()
     with tracked_request.span(operation="HTTP/{}".format(method)) as span:
-        span.tag("url", text_type(url))
+        span.tag("url", url)
         return wrapped(*args, **kwargs)

tests/integration/instruments/test_urllib3.py

@@ -91,6 +91,29 @@ def test_request(tracked_request):
     assert span.tags["url"] == "https://example.com:443/"
 
 
+def test_second_request(tracked_request):
+    ensure_installed()
+    with tracked_request.span("Test"), httpretty.enabled(allow_net_connect=False):
+        httpretty.register_uri(
+            httpretty.GET, "https://example.com/foo", body="Hello World!"
+        )
+        httpretty.register_uri(
+            httpretty.GET, "https://example.org/bar", body="Hello World!"
+        )
+
+        http = urllib3_cert_pool_manager()
+        http.request("GET", "https://example.com/foo")
+        http.request("GET", "https://example.org/bar")
+
+    assert len(tracked_request.complete_spans) == 3
+    assert (
+        tracked_request.complete_spans[0].tags["url"] == "https://example.com:443/foo"
+    )
+    assert (
+        tracked_request.complete_spans[1].tags["url"] == "https://example.org:443/bar"
+    )
+
+
 def test_request_type_error(tracked_request):
     ensure_installed()
     with pytest.raises(TypeError):
@@ -101,7 +124,7 @@ def test_request_type_error(tracked_request):
     assert len(tracked_request.complete_spans) == 1
     span = tracked_request.complete_spans[0]
     assert span.operation == "HTTP/Unknown"
-    assert span.tags["url"] == "https://example.com:443/"
+    assert span.tags["url"] == "Unknown"
 
 
 def test_request_no_absolute_url(caplog, tracked_request):