Add Redis instrumentation query sanitization (#1572)

* Add Redis instrumentation query sanitization

Add a query sanitizer to the Redis instrumentation. This can be disabled
with the `sanitize_query = False` config option.

Given the query `SET key value`, the sanitized query becomes `SET ? ?`.
Both the keys and values are sanitized, as both can contain PII data.

The Redis queries are sanitized by default. This changes the default
behavior of this instrumentation. Previously it reported unsanitized
Redis queries.

This was previously discussed in the previous implementation of this PR
in PR #1571

Closes #1548

* Update Redis sanitize_query option documentation

Changes suggested in
#1572 (comment)

* Remove uninstrument & instrument from test setup

The Redis test that performs the tests with the default options, doesn't
need to uninstrument and then instrument the instrumentor. This commit
removes the unnecessary setup code. The setup code is already present at
the top of the file.

* Fix code style formatting

* Update Redis functional tests

- Update the sanitizer to also account for a max `db.statement`
  attribute value length. No longer than 1000 characters.
- Update the functional tests to assume the queries are sanitized by
  default.
- Add new tests that test the behavior with sanitization turned off.
  Only for the tests in the first test class. I don't think it's needed
  to duplicate this test for the clustered and async setup combinations.

* Test Redis unsanitized queries by default

Change the Redis functional tests so that they test the unsanitized
query by default, and test the sanitized query results in the separate
test functions.

This is a partial revert of the previous commit
8d56c2f

* Fix formatting issue in Redis utils

* Disable Redis query sanitization by default

Update the Redis instrumentation library to not change the default
behavior for the Redis instrumentation. This can be enabled at a later
time when the spec discussion about this topic has concluded.

open-telemetry/opentelemetry-specification#3104

* Fix pylint issue

Remove else statement.

* Update changelog about Redis query sanitization default

[ci skip]

Co-authored-by: Srikanth Chekuri <srikanth.chekuri92@gmail.com>

* Fix potential error on Redis args being 0

Check the length of the args array and return an empty string if there
are no args.

That way it won't cause an IndexError if the args array is empty and it
tries to fetch the first element, which should be the Redis command.

---------

Co-authored-by: Srikanth Chekuri <srikanth.chekuri92@gmail.com>

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- `opentelemetry-instrumentation-redis` Add `sanitize_query` config option to allow query sanitization.  ([#1572](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1572))
 - `opentelemetry-instrumentation-celery` Record exceptions as events on the span.
   ([#1573](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1573))
 - Add metric instrumentation for urllib

instrumentation/opentelemetry-instrumentation-redis/src/opentelemetry/instrumentation/redis/__init__.py

@@ -64,6 +64,8 @@ async def redis_get():
 response_hook (Callable) - a function with extra user-defined logic to be performed after performing the request
 this function signature is: def response_hook(span: Span, instance: redis.connection.Connection, response) -> None
 
+sanitize_query (Boolean) - default False, enable the Redis query sanitization
+
 for example:
 
 .. code: python
@@ -139,9 +141,11 @@ def _instrument(
     tracer,
     request_hook: _RequestHookT = None,
     response_hook: _ResponseHookT = None,
+    sanitize_query: bool = False,
 ):
     def _traced_execute_command(func, instance, args, kwargs):
-        query = _format_command_args(args)
+        query = _format_command_args(args, sanitize_query)
+
         if len(args) > 0 and args[0]:
             name = args[0]
         else:
@@ -169,7 +173,9 @@ def _traced_execute_pipeline(func, instance, args, kwargs):
             )
 
             cmds = [
-                _format_command_args(c.args if hasattr(c, "args") else c[0])
+                _format_command_args(
+                    c.args if hasattr(c, "args") else c[0], sanitize_query
+                )
                 for c in command_stack
             ]
             resource = "\n".join(cmds)
@@ -281,6 +287,7 @@ def _instrument(self, **kwargs):
             tracer,
             request_hook=kwargs.get("request_hook"),
             response_hook=kwargs.get("response_hook"),
+            sanitize_query=kwargs.get("sanitize_query", False),
         )
 
     def _uninstrument(self, **kwargs):

instrumentation/opentelemetry-instrumentation-redis/src/opentelemetry/instrumentation/redis/util.py

@@ -48,11 +48,27 @@ def _extract_conn_attributes(conn_kwargs):
     return attributes
 
 
-def _format_command_args(args):
-    """Format command arguments and trim them as needed"""
-    value_max_len = 100
-    value_too_long_mark = "..."
+def _format_command_args(args, sanitize_query):
+    """Format and sanitize command arguments, and trim them as needed"""
     cmd_max_len = 1000
+    value_too_long_mark = "..."
+    if sanitize_query:
+        # Sanitized query format: "COMMAND ? ?"
+        args_length = len(args)
+        if args_length > 0:
+            out = [str(args[0])] + ["?"] * (args_length - 1)
+            out_str = " ".join(out)
+
+            if len(out_str) > cmd_max_len:
+                out_str = (
+                    out_str[: cmd_max_len - len(value_too_long_mark)]
+                    + value_too_long_mark
+                )
+        else:
+            out_str = ""
+        return out_str
+
+    value_max_len = 100
     length = 0
     out = []
     for arg in args:

instrumentation/opentelemetry-instrumentation-redis/tests/test_redis.py

@@ -148,6 +148,40 @@ def request_hook(span, conn, args, kwargs):
         span = spans[0]
         self.assertEqual(span.attributes.get(custom_attribute_name), "GET")
 
+    def test_query_sanitizer_enabled(self):
+        redis_client = redis.Redis()
+        connection = redis.connection.Connection()
+        redis_client.connection = connection
+
+        RedisInstrumentor().uninstrument()
+        RedisInstrumentor().instrument(
+            tracer_provider=self.tracer_provider,
+            sanitize_query=True,
+        )
+
+        with mock.patch.object(redis_client, "connection"):
+            redis_client.set("key", "value")
+
+        spans = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans), 1)
+
+        span = spans[0]
+        self.assertEqual(span.attributes.get("db.statement"), "SET ? ?")
+
+    def test_query_sanitizer_disabled(self):
+        redis_client = redis.Redis()
+        connection = redis.connection.Connection()
+        redis_client.connection = connection
+
+        with mock.patch.object(redis_client, "connection"):
+            redis_client.set("key", "value")
+
+        spans = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans), 1)
+
+        span = spans[0]
+        self.assertEqual(span.attributes.get("db.statement"), "SET key value")
+
     def test_no_op_tracer_provider(self):
         RedisInstrumentor().uninstrument()
         tracer_provider = trace.NoOpTracerProvider()

tests/opentelemetry-docker-tests/tests/redis/test_redis_functional.py

@@ -45,6 +45,27 @@ def _check_span(self, span, name):
         )
         self.assertEqual(span.attributes[SpanAttributes.NET_PEER_PORT], 6379)
 
+    def test_long_command_sanitized(self):
+        RedisInstrumentor().uninstrument()
+        RedisInstrumentor().instrument(
+            tracer_provider=self.tracer_provider, sanitize_query=True
+        )
+
+        self.redis_client.mget(*range(2000))
+
+        spans = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans), 1)
+        span = spans[0]
+        self._check_span(span, "MGET")
+        self.assertTrue(
+            span.attributes.get(SpanAttributes.DB_STATEMENT).startswith(
+                "MGET ? ? ? ?"
+            )
+        )
+        self.assertTrue(
+            span.attributes.get(SpanAttributes.DB_STATEMENT).endswith("...")
+        )
+
     def test_long_command(self):
         self.redis_client.mget(*range(1000))
 
@@ -61,6 +82,22 @@ def test_long_command(self):
             span.attributes.get(SpanAttributes.DB_STATEMENT).endswith("...")
         )
 
+    def test_basics_sanitized(self):
+        RedisInstrumentor().uninstrument()
+        RedisInstrumentor().instrument(
+            tracer_provider=self.tracer_provider, sanitize_query=True
+        )
+
+        self.assertIsNone(self.redis_client.get("cheese"))
+        spans = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans), 1)
+        span = spans[0]
+        self._check_span(span, "GET")
+        self.assertEqual(
+            span.attributes.get(SpanAttributes.DB_STATEMENT), "GET ?"
+        )
+        self.assertEqual(span.attributes.get("db.redis.args_length"), 2)
+
     def test_basics(self):
         self.assertIsNone(self.redis_client.get("cheese"))
         spans = self.memory_exporter.get_finished_spans()
@@ -72,6 +109,28 @@ def test_basics(self):
         )
         self.assertEqual(span.attributes.get("db.redis.args_length"), 2)
 
+    def test_pipeline_traced_sanitized(self):
+        RedisInstrumentor().uninstrument()
+        RedisInstrumentor().instrument(
+            tracer_provider=self.tracer_provider, sanitize_query=True
+        )
+
+        with self.redis_client.pipeline(transaction=False) as pipeline:
+            pipeline.set("blah", 32)
+            pipeline.rpush("foo", "éé")
+            pipeline.hgetall("xxx")
+            pipeline.execute()
+
+        spans = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans), 1)
+        span = spans[0]
+        self._check_span(span, "SET RPUSH HGETALL")
+        self.assertEqual(
+            span.attributes.get(SpanAttributes.DB_STATEMENT),
+            "SET ? ?\nRPUSH ? ?\nHGETALL ?",
+        )
+        self.assertEqual(span.attributes.get("db.redis.pipeline_length"), 3)
+
     def test_pipeline_traced(self):
         with self.redis_client.pipeline(transaction=False) as pipeline:
             pipeline.set("blah", 32)
@@ -89,6 +148,27 @@ def test_pipeline_traced(self):
         )
         self.assertEqual(span.attributes.get("db.redis.pipeline_length"), 3)
 
+    def test_pipeline_immediate_sanitized(self):
+        RedisInstrumentor().uninstrument()
+        RedisInstrumentor().instrument(
+            tracer_provider=self.tracer_provider, sanitize_query=True
+        )
+
+        with self.redis_client.pipeline() as pipeline:
+            pipeline.set("a", 1)
+            pipeline.immediate_execute_command("SET", "b", 2)
+            pipeline.execute()
+
+        spans = self.memory_exporter.get_finished_spans()
+        # expecting two separate spans here, rather than a
+        # single span for the whole pipeline
+        self.assertEqual(len(spans), 2)
+        span = spans[0]
+        self._check_span(span, "SET")
+        self.assertEqual(
+            span.attributes.get(SpanAttributes.DB_STATEMENT), "SET ? ?"
+        )
+
     def test_pipeline_immediate(self):
         with self.redis_client.pipeline() as pipeline:
             pipeline.set("a", 1)