feat: Add twisted instrumentation and unit/integration tests by CagriYonca · Pull Request #888 · instana/python-sensor

CagriYonca · 2026-07-13T09:27:21Z

Added twisted webserver instrumentation and related tests.

Signed-off-by: Cagri Yonca <cagri@ibm.com>

sonarqubecloud · 2026-07-13T12:26:46Z

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
99.2% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

GSVarsha · 2026-07-20T09:36:34Z

+    def test_get(self) -> None:
+        with self.tracer.start_as_current_span("test"):
+            response = requests.get(testenv["twisted_server"] + "/")
+
+        time.sleep(0.5)
+        spans = self.recorder.queued_spans()
+        assert len(spans) == 3
+
+        server_span = get_first_span_by_name(spans, "twisted-server")
+        client_span = get_first_span_by_name(spans, "urllib3")
+        test_span = get_first_span_by_name(spans, "sdk")
+
+        assert server_span
+        assert client_span
+        assert test_span
+
+        assert not get_current_span().is_recording()
+
+        # Same traceId
+        traceId = test_span.t
+        assert traceId == client_span.t
+        assert traceId == server_span.t
+
+        # Parent relationships
+        assert client_span.p == test_span.s
+        assert server_span.p == client_span.s
+
+        # Error logging
+        assert not test_span.ec
+        assert not client_span.ec
+        assert not server_span.ec
+
+        assert server_span.data["http"]["status"] == 200
+        assert testenv["twisted_server"] + "/" == server_span.data["http"]["url"]
+        assert not server_span.data["http"].get("params")
+        assert server_span.data["http"]["method"] == "GET"
+
+        assert "X-INSTANA-T" in response.headers
+        assert response.headers["X-INSTANA-T"] == hex_id(traceId)
+        assert "X-INSTANA-S" in response.headers
+        assert response.headers["X-INSTANA-S"] == hex_id(server_span.s)
+        assert "X-INSTANA-L" in response.headers
+        assert response.headers["X-INSTANA-L"] == "1"
+        assert "Server-Timing" in response.headers
+        assert response.headers["Server-Timing"] == f"intid;desc={hex_id(traceId)}"
+
+    def test_post(self) -> None:
+        with self.tracer.start_as_current_span("test"):
+            _ = requests.post(testenv["twisted_server"] + "/", data={"hello": "post"})
+
+        time.sleep(0.5)
+        spans = self.recorder.queued_spans()
+        assert len(spans) == 3
+
+        server_span = get_first_span_by_name(spans, "twisted-server")
+        client_span = get_first_span_by_name(spans, "urllib3")
+        test_span = get_first_span_by_name(spans, "sdk")
+
+        assert server_span
+        assert client_span
+        assert test_span
+
+        assert not get_current_span().is_recording()
+
+        # Same traceId
+        traceId = test_span.t
+        assert traceId == client_span.t
+        assert traceId == server_span.t
+
+        # Parent relationships
+        assert client_span.p == test_span.s
+        assert server_span.p == client_span.s
+
+        # Error logging
+        assert not test_span.ec
+        assert not client_span.ec
+        assert not server_span.ec
+
+        assert server_span.data["http"]["status"] == 200
+        assert testenv["twisted_server"] + "/" == server_span.data["http"]["url"]
+        assert not server_span.data["http"].get("params")
+        assert server_span.data["http"]["method"] == "POST"
+
+    def test_get_301(self) -> None:
+        with self.tracer.start_as_current_span("test"):
+            _ = requests.get(testenv["twisted_server"] + "/301", allow_redirects=False)
+
+        time.sleep(0.5)
+        spans = self.recorder.queued_spans()
+        assert len(spans) == 3
+
+        server_span = get_first_span_by_name(spans, "twisted-server")
+        client_span = get_first_span_by_name(spans, "urllib3")
+        test_span = get_first_span_by_name(spans, "sdk")
+
+        assert server_span
+        assert client_span
+        assert test_span
+
+        assert not get_current_span().is_recording()
+
+        # Same traceId
+        traceId = test_span.t
+        assert traceId == client_span.t
+        assert traceId == server_span.t
+
+        # Parent relationships
+        assert client_span.p == test_span.s
+        assert server_span.p == client_span.s
+
+        assert server_span.data["http"]["status"] == 301
+        assert testenv["twisted_server"] + "/301" == server_span.data["http"]["url"]
+        assert server_span.data["http"]["method"] == "GET"
+
+    def test_get_404(self) -> None:
+        with self.tracer.start_as_current_span("test"):
+            _ = requests.get(testenv["twisted_server"] + "/404")
+
+        time.sleep(0.5)
+        spans = self.recorder.queued_spans()
+        assert len(spans) == 3
+
+        server_span = get_first_span_by_name(spans, "twisted-server")
+        client_span = get_first_span_by_name(spans, "urllib3")
+        test_span = get_first_span_by_name(spans, "sdk")
+
+        assert server_span
+        assert client_span
+        assert test_span
+
+        assert server_span.data["http"]["status"] == 404
+        assert testenv["twisted_server"] + "/404" == server_span.data["http"]["url"]
+
+    def test_get_500(self) -> None:
+        with self.tracer.start_as_current_span("test"):
+            _ = requests.get(testenv["twisted_server"] + "/500")
+
+        time.sleep(0.5)
+        spans = self.recorder.queued_spans()
+        assert len(spans) == 3
+
+        server_span = get_first_span_by_name(spans, "twisted-server")
+        client_span = get_first_span_by_name(spans, "urllib3")
+        test_span = get_first_span_by_name(spans, "sdk")
+
+        assert server_span
+        assert client_span
+        assert test_span
+
+        assert not get_current_span().is_recording()
+
+        # Same traceId
+        traceId = test_span.t
+        assert traceId == client_span.t
+        assert traceId == server_span.t
+
+        assert server_span.data["http"]["status"] == 500
+        assert testenv["twisted_server"] + "/500" == server_span.data["http"]["url"]
+
+        # Error logging
+        assert not test_span.ec
+        assert client_span.ec == 1
+        assert server_span.ec == 1
+
+    def test_get_with_params_to_scrub(self) -> None:
+        with self.tracer.start_as_current_span("test"):
+            _ = requests.get(testenv["twisted_server"] + "/", params={"secret": "yeah"})
+
+        time.sleep(0.5)
+        spans = self.recorder.queued_spans()
+        assert len(spans) == 3
+
+        server_span = get_first_span_by_name(spans, "twisted-server")
+        client_span = get_first_span_by_name(spans, "urllib3")
+        test_span = get_first_span_by_name(spans, "sdk")
+
+        assert server_span
+        assert client_span
+        assert test_span
+
+        assert not get_current_span().is_recording()
+
+        # Same traceId
+        traceId = test_span.t
+        assert traceId == client_span.t
+        assert traceId == server_span.t
+
+        assert server_span.data["http"]["status"] == 200
+        assert testenv["twisted_server"] + "/" == server_span.data["http"]["url"]
+        assert server_span.data["http"]["params"] == "secret=<redacted>"
+
+    def test_request_header_capture(self) -> None:
+        original_extra_http_headers = agent.options.extra_http_headers
+        agent.options.extra_http_headers = ["X-Capture-This", "X-Capture-That"]
+
+        with self.tracer.start_as_current_span("test"):
+            _ = requests.get(
+                testenv["twisted_server"] + "/",
+                headers={"X-Capture-This": "this", "X-Capture-That": "that"},
+            )
+
+        agent.options.extra_http_headers = original_extra_http_headers
+
+        time.sleep(0.5)
+        spans = self.recorder.queued_spans()
+        assert len(spans) == 3
+
+        server_span = get_first_span_by_name(spans, "twisted-server")
+        client_span = get_first_span_by_name(spans, "urllib3")
+        test_span = get_first_span_by_name(spans, "sdk")
+
+        assert server_span
+        assert client_span
+        assert test_span
+
+        assert "X-Capture-This" in server_span.data["http"]["header"]
+        assert server_span.data["http"]["header"]["X-Capture-This"] == "this"
+        assert "X-Capture-That" in server_span.data["http"]["header"]
+        assert server_span.data["http"]["header"]["X-Capture-That"] == "that"
+
+    def test_response_header_capture(self) -> None:
+        original_extra_http_headers = agent.options.extra_http_headers
+        agent.options.extra_http_headers = ["X-Capture-This-Too", "X-Capture-That-Too"]
+
+        with self.tracer.start_as_current_span("test"):
+            _ = requests.get(testenv["twisted_server"] + "/response_headers")
+
+        agent.options.extra_http_headers = original_extra_http_headers
+
+        time.sleep(0.5)
+        spans = self.recorder.queued_spans()
+        assert len(spans) == 3
+
+        server_span = get_first_span_by_name(spans, "twisted-server")
+        client_span = get_first_span_by_name(spans, "urllib3")
+        test_span = get_first_span_by_name(spans, "sdk")
+
+        assert server_span
+        assert client_span
+        assert test_span
+
+        assert "X-Capture-This-Too" in server_span.data["http"]["header"]
+        assert server_span.data["http"]["header"]["X-Capture-This-Too"] == "this too"
+        assert "X-Capture-That-Too" in server_span.data["http"]["header"]
+        assert server_span.data["http"]["header"]["X-Capture-That-Too"] == "that too"


The first 8 test methods in TestTwistedClient are functionally identical to the 8 tests of the same name in TestTwistedServer. Every one of them:

Looks up get_first_span_by_name(spans, "urllib3") — the variable is even named client_span, but it holds the urllib3 span, not a twisted-client span

Never checks for a span named "twisted-client" at all

GSVarsha · 2026-07-21T05:49:14Z

+            span.set_attribute(SpanAttributes.HTTP_METHOD, method_str)
+
+            # Build / augment headers with trace correlation
+            from twisted.web.http_headers import Headers as TwistedHeaders


Please move this to the top, in the outermost try block

GSVarsha · 2026-07-21T05:49:37Z

+    def _finish_tracing(result: Any, span: "InstanaSpan") -> Any:
+        """Callback/errback attached to the Agent.request Deferred."""
+        try:
+            from twisted.python.failure import Failure


Same as here

GSVarsha · 2026-07-21T06:01:42Z

+
+            # Capture outgoing request headers
+            headers_dict = {
+                k.decode("latin-1"): v[0].decode("latin-1")


As mentioned in the official twisted doc here, header names are encoded using ISO-8859-1 (latin-1) and header values are encoded using UTF-8.

getAllRawHeaders() returns raw bytes in both cases, so the caller must decode each correctly:

Suggested change

k.decode("latin-1"): v[0].decode("latin-1")

k.decode("latin-1"): v[0].decode("utf-8")

GSVarsha · 2026-07-21T06:02:01Z

+
+            # Capture response headers
+            headers_dict = {
+                k.decode("latin-1"): v[0].decode("latin-1")


Same as here

GSVarsha · 2026-07-21T06:02:10Z

+            parent_context = None
+            if request.requestHeaders:
+                headers_dict: dict[str, str] = {
+                    k.decode("latin-1"): v[0].decode("latin-1")


Same as here

GSVarsha · 2026-07-21T06:02:19Z

+
+                    # Capture response headers
+                    response_hdrs = {
+                        k.decode("latin-1"): v[0].decode("latin-1")


Same as here

GSVarsha

Few requests

CagriYonca self-assigned this Jul 13, 2026

CagriYonca force-pushed the twisted branch 4 times, most recently from 1585ae8 to b116c82 Compare July 13, 2026 11:12

feat: Add twisted instrumentation and unit/integration tests

e558a6f

Signed-off-by: Cagri Yonca <cagri@ibm.com>

CagriYonca force-pushed the twisted branch from 4624e6d to e558a6f Compare July 13, 2026 12:10

CagriYonca marked this pull request as ready for review July 13, 2026 12:10

CagriYonca requested a review from a team as a code owner July 13, 2026 12:10

pvital added the feature label Jul 13, 2026

GSVarsha reviewed Jul 20, 2026

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GSVarsha reviewed Jul 21, 2026

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feat: Add twisted instrumentation and unit/integration tests#888

feat: Add twisted instrumentation and unit/integration tests#888
CagriYonca wants to merge 1 commit into
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CagriYonca commented Jul 13, 2026

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sonarqubecloud Bot commented Jul 13, 2026

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GSVarsha Jul 20, 2026

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GSVarsha Jul 21, 2026 •

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	k.decode("latin-1"): v[0].decode("latin-1")
	k.decode("latin-1"): v[0].decode("utf-8")

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CagriYonca commented Jul 13, 2026

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sonarqubecloud Bot commented Jul 13, 2026

Quality Gate passed

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GSVarsha Jul 21, 2026 •

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