Repository: open-telemetry/opentelemetry-python-contrib

Issue:
Add more features for adding HTTP request / response headers to spans.
I already have https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1172 open for this, and I'll be breaking it in to smaller pieces at @lzchen 's request.

**Is your feature request related to a problem?**
Currently, you can only provide a list of full HTTP request / response header names to be added to the span.

There is also no capacity for header value redaction.

**Describe the solution you'd like**
It would be nice to be able to specify a regex or "all" to get all headers.

Header value redaction is also a must-have for us.

**Describe alternatives you've considered**
I considered doing this in my application, but it makes more sense to add it here.



Discussion:

Resolving patch:
diff --git a/instrumentation/opentelemetry-instrumentation-pyramid/src/opentelemetry/instrumentation/pyramid/__init__.py b/instrumentation/opentelemetry-instrumentation-pyramid/src/opentelemetry/instrumentation/pyramid/__init__.py
--- a/instrumentation/opentelemetry-instrumentation-pyramid/src/opentelemetry/instrumentation/pyramid/__init__.py
+++ b/instrumentation/opentelemetry-instrumentation-pyramid/src/opentelemetry/instrumentation/pyramid/__init__.py
@@ -55,7 +55,7 @@
 ---------------------------------
 
 If you use Method 2 and then set tweens for your application with the ``pyramid.tweens`` setting,
-you need to add ``opentelemetry.instrumentation.pyramid.trace_tween_factory`` explicitly to the list,
+you need to explicitly add ``opentelemetry.instrumentation.pyramid.trace_tween_factory`` to the list,
 *as well as* instrumenting the config as shown above.
 
 For example:
@@ -79,8 +79,9 @@
 
 Exclude lists
 *************
-To exclude certain URLs from being tracked, set the environment variable ``OTEL_PYTHON_PYRAMID_EXCLUDED_URLS``
-(or ``OTEL_PYTHON_EXCLUDED_URLS`` as fallback) with comma delimited regexes representing which URLs to exclude.
+To exclude certain URLs from tracking, set the environment variable ``OTEL_PYTHON_PYRAMID_EXCLUDED_URLS``
+(or ``OTEL_PYTHON_EXCLUDED_URLS`` to cover all instrumentations) to a string of comma delimited regexes that match the
+URLs.
 
 For example,
 
@@ -92,54 +93,93 @@
 
 Capture HTTP request and response headers
 *****************************************
-You can configure the agent to capture predefined HTTP headers as span attributes, according to the `semantic convention <https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/semantic_conventions/http.md#http-request-and-response-headers>`_.
+You can configure the agent to capture specified HTTP headers as span attributes, according to the
+`semantic convention <https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/semantic_conventions/http.md#http-request-and-response-headers>`_.
 
 Request headers
 ***************
-To capture predefined HTTP request headers as span attributes, set the environment variable ``OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST``
-to a comma-separated list of HTTP header names.
+To capture HTTP request headers as span attributes, set the environment variable
+``OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST`` to a comma delimited list of HTTP header names.
 
 For example,
-
 ::
 
     export OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST="content-type,custom_request_header"
 
-will extract ``content-type`` and ``custom_request_header`` from request headers and add them as span attributes.
+will extract ``content-type`` and ``custom_request_header`` from the request headers and add them as span attributes.
+
+Request header names in Pyramid are case-insensitive and ``-`` characters are replaced by ``_``. So, giving the header
+name as ``CUStom_Header`` in the environment variable will capture the header named ``custom-header``.
+
+Regular expressions may also be used to match multiple headers that correspond to the given pattern.  For example:
+::
+
+    export OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST="Accept.*,X-.*"
+
+Would match all request headers that start with ``Accept`` and ``X-``.
 
-It is recommended that you should give the correct names of the headers to be captured in the environment variable.
-Request header names in pyramid are case insensitive and - characters are replaced by _. So, giving header name as ``CUStom_Header`` in environment variable will be able capture header with name ``custom-header``.
+To capture all request headers, set ``OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST`` to ``".*"``.
+::
+
+    export OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST=".*"
 
-The name of the added span attribute will follow the format ``http.request.header.<header_name>`` where ``<header_name>`` being the normalized HTTP header name (lowercase, with - characters replaced by _ ).
-The value of the attribute will be single item list containing all the header values.
+The name of the added span attribute will follow the format ``http.request.header.<header_name>`` where ``<header_name>``
+is the normalized HTTP header name (lowercase, with ``-`` replaced by ``_``). The value of the attribute will be a
+single item list containing all the header values.
 
-Example of the added span attribute,
+For example:
 ``http.request.header.custom_request_header = ["<value1>,<value2>"]``
 
 Response headers
 ****************
-To capture predefined HTTP response headers as span attributes, set the environment variable ``OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE``
-to a comma-separated list of HTTP header names.
+To capture HTTP response headers as span attributes, set the environment variable
+``OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE`` to a comma delimited list of HTTP header names.
 
 For example,
-
 ::
 
     export OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE="content-type,custom_response_header"
 
-will extract ``content-type`` and ``custom_response_header`` from response headers and add them as span attributes.
+will extract ``content-type`` and ``custom_response_header`` from the response headers and add them as span attributes.
+
+Response header names in Pyramid are case-insensitive. So, giving the header name as ``CUStom-Header`` in the environment
+variable will capture the header named ``custom-header``.
+
+Regular expressions may also be used to match multiple headers that correspond to the given pattern.  For example:
+::
+
+    export OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE="Content.*,X-.*"
+
+Would match all response headers that start with ``Content`` and ``X-``.
 
-It is recommended that you should give the correct names of the headers to be captured in the environment variable.
-Response header names captured in pyramid are case insensitive. So, giving header name as ``CUStomHeader`` in environment variable will be able capture header with name ``customheader``.
+To capture all response headers, set ``OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE`` to ``".*"``.
+::
+
+    export OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE=".*"
 
-The name of the added span attribute will follow the format ``http.response.header.<header_name>`` where ``<header_name>`` being the normalized HTTP header name (lowercase, with - characters replaced by _ ).
-The value of the attribute will be single item list containing all the header values.
+The name of the added span attribute will follow the format ``http.response.header.<header_name>`` where ``<header_name>``
+is the normalized HTTP header name (lowercase, with ``-`` replaced by ``_``). The value of the attribute will be a
+single item list containing all the header values.
 
-Example of the added span attribute,
+For example:
 ``http.response.header.custom_response_header = ["<value1>,<value2>"]``
 
+Sanitizing headers
+******************
+In order to prevent storing sensitive data such as personally identifiable information (PII), session keys, passwords,
+etc, set the environment variable ``OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SANITIZE_FIELDS``
+to a comma delimited list of HTTP header names to be sanitized.  Regexes may be used, and all header names will be
+matched in a case-insensitive manner.
+
+For example,
+::
+
+    export OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SANITIZE_FIELDS=".*session.*,set-cookie"
+
+will replace the value of headers such as ``session-id`` and ``set-cookie`` with ``[REDACTED]`` in the span.
+
 Note:
-    Environment variable names to capture http headers are still experimental, and thus are subject to change.
+    The environment variable names used to capture HTTP headers are still experimental, and thus are subject to change.
 
 API
 ---


Test patch:
diff --git a/instrumentation/opentelemetry-instrumentation-pyramid/tests/pyramid_base_test.py b/instrumentation/opentelemetry-instrumentation-pyramid/tests/pyramid_base_test.py
--- a/instrumentation/opentelemetry-instrumentation-pyramid/tests/pyramid_base_test.py
+++ b/instrumentation/opentelemetry-instrumentation-pyramid/tests/pyramid_base_test.py
@@ -40,6 +40,9 @@ def _custom_response_header_endpoint(request):
             "content-type": "text/plain; charset=utf-8",
             "content-length": "7",
             "my-custom-header": "my-custom-value-1,my-custom-header-2",
+            "my-custom-regex-header-1": "my-custom-regex-value-1,my-custom-regex-value-2",
+            "My-Custom-Regex-Header-2": "my-custom-regex-value-3,my-custom-regex-value-4",
+            "my-secret-header": "my-secret-value",
             "dont-capture-me": "test-value",
         }
         return Response("Testing", headers=headers)
diff --git a/instrumentation/opentelemetry-instrumentation-pyramid/tests/test_automatic.py b/instrumentation/opentelemetry-instrumentation-pyramid/tests/test_automatic.py
--- a/instrumentation/opentelemetry-instrumentation-pyramid/tests/test_automatic.py
+++ b/instrumentation/opentelemetry-instrumentation-pyramid/tests/test_automatic.py
@@ -28,6 +28,7 @@
 from opentelemetry.trace import SpanKind
 from opentelemetry.trace.status import StatusCode
 from opentelemetry.util.http import (
+    OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SANITIZE_FIELDS,
     OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST,
     OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE,
     _active_requests_count_attrs,
@@ -285,24 +286,23 @@ def test_with_existing_span(self):
             )
 
 
+@patch.dict(
+    "os.environ",
+    {
+        OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SANITIZE_FIELDS: ".*my-secret.*",
+        OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST: "Custom-Test-Header-1,Custom-Test-Header-2,invalid-header,Regex-Test-Header-.*,Regex-Invalid-Test-Header-.*,.*my-secret.*",
+        OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE: "content-type,content-length,my-custom-header,invalid-header,my-custom-regex-header-.*,invalid-regex-header-.*,.*my-secret.*",
+    },
+)
 class TestCustomRequestResponseHeaders(InstrumentationTest, WsgiTestBase):
     def setUp(self):
         super().setUp()
         PyramidInstrumentor().instrument()
         self.config = Configurator()
         self._common_initialization(self.config)
-        self.env_patch = patch.dict(
-            "os.environ",
-            {
-                OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST: "Custom-Test-Header-1,Custom-Test-Header-2,invalid-header",
-                OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE: "content-type,content-length,my-custom-header,invalid-header",
-            },
-        )
-        self.env_patch.start()
 
     def tearDown(self) -> None:
         super().tearDown()
-        self.env_patch.stop()
         with self.disable_logging():
             PyramidInstrumentor().uninstrument()
 
@@ -311,6 +311,9 @@ def test_custom_request_header_added_in_server_span(self):
             "Custom-Test-Header-1": "Test Value 1",
             "Custom-Test-Header-2": "TestValue2,TestValue3",
             "Custom-Test-Header-3": "TestValue4",
+            "Regex-Test-Header-1": "Regex Test Value 1",
+            "regex-test-header-2": "RegexTestValue2,RegexTestValue3",
+            "My-Secret-Header": "My Secret Value",
         }
         resp = self.client.get("/hello/123", headers=headers)
         self.assertEqual(200, resp.status_code)
@@ -320,6 +323,11 @@ def test_custom_request_header_added_in_server_span(self):
             "http.request.header.custom_test_header_2": (
                 "TestValue2,TestValue3",
             ),
+            "http.request.header.regex_test_header_1": ("Regex Test Value 1",),
+            "http.request.header.regex_test_header_2": (
+                "RegexTestValue2,RegexTestValue3",
+            ),
+            "http.request.header.my_secret_header": ("[REDACTED]",),
         }
         not_expected = {
             "http.request.header.custom_test_header_3": ("TestValue4",),
@@ -361,6 +369,13 @@ def test_custom_response_header_added_in_server_span(self):
             "http.response.header.my_custom_header": (
                 "my-custom-value-1,my-custom-header-2",
             ),
+            "http.response.header.my_custom_regex_header_1": (
+                "my-custom-regex-value-1,my-custom-regex-value-2",
+            ),
+            "http.response.header.my_custom_regex_header_2": (
+                "my-custom-regex-value-3,my-custom-regex-value-4",
+            ),
+            "http.response.header.my_secret_header": ("[REDACTED]",),
         }
         not_expected = {
             "http.response.header.dont_capture_me": ("test-value",)
@@ -390,6 +405,14 @@ def test_custom_response_header_not_added_in_internal_span(self):
                 self.assertNotIn(key, span.attributes)
 
 
+@patch.dict(
+    "os.environ",
+    {
+        OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SANITIZE_FIELDS: ".*my-secret.*",
+        OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST: "Custom-Test-Header-1,Custom-Test-Header-2,invalid-header,Regex-Test-Header-.*,Regex-Invalid-Test-Header-.*,.*my-secret.*",
+        OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE: "content-type,content-length,my-custom-header,invalid-header,my-custom-regex-header-.*,invalid-regex-header-.*,.*my-secret.*",
+    },
+)
 class TestCustomHeadersNonRecordingSpan(InstrumentationTest, WsgiTestBase):
     def setUp(self):
         super().setUp()
@@ -401,18 +424,9 @@ def setUp(self):
         PyramidInstrumentor().instrument()
         self.config = Configurator()
         self._common_initialization(self.config)
-        self.env_patch = patch.dict(
-            "os.environ",
-            {
-                OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_REQUEST: "Custom-Test-Header-1,Custom-Test-Header-2,invalid-header",
-                OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SERVER_RESPONSE: "content-type,content-length,my-custom-header,invalid-header",
-            },
-        )
-        self.env_patch.start()
 
     def tearDown(self) -> None:
         super().tearDown()
-        self.env_patch.stop()
         with self.disable_logging():
             PyramidInstrumentor().uninstrument()