feat: Add mTLS support for telemetry endpoint in adk.py.

This change enables the telemetry exporter to use mTLS endpoints when configured, by dynamically determining the correct endpoint and configuring the requests session accordingly. It introduces helper functions to handle client certificate source management.

PiperOrigin-RevId: 912220336

Author: vertex-sdk-bot

tests/unit/vertex_adk/test_agent_engine_templates_adk.py

@@ -16,29 +16,30 @@
 import importlib
 import json
 import os
-import cloudpickle
-import sys
 import re
-from unittest import mock
+import sys
 from typing import Optional
+from unittest import mock
+import uuid
 
+import cloudpickle
 from google import auth
+from google.api_core import operation as ga_operation
 from google.auth import credentials as auth_credentials
+from google.auth.transport import mtls
 from google.cloud import storage
-import vertexai
 from google.cloud import aiplatform
-from google.cloud.aiplatform_v1 import types as aip_types
-from google.cloud.aiplatform_v1.services import reasoning_engine_service
+import vertexai
 from google.cloud.aiplatform import base
 from google.cloud.aiplatform import initializer
-from vertexai.agent_engines import _utils
+from google.cloud.aiplatform_v1 import types as aip_types
+from google.cloud.aiplatform_v1.services import reasoning_engine_service
 from vertexai import agent_engines
-from vertexai.agent_engines.templates import adk as adk_template
 from vertexai.agent_engines import _agent_engines
-from google.api_core import operation as ga_operation
+from vertexai.agent_engines import _utils
+from vertexai.agent_engines.templates import adk as adk_template
 from google.genai import types
 import pytest
-import uuid
 
 
 try:
@@ -1066,6 +1067,7 @@ def update_agent_engine_mock():
 
 @pytest.mark.usefixtures("google_auth_mock")
 class TestAgentEngines:
+
     def setup_method(self):
         importlib.reload(initializer)
         importlib.reload(aiplatform)
@@ -1167,3 +1169,260 @@ def test_update_default_telemetry_enablement(
         assert _utils.to_dict(deployment_spec)["env"] == [
             {"name": key, "value": value} for key, value in expected_env_vars.items()
         ]
+
+
+class TestAdkAppMtls:
+    """Test cases for mTLS functionality in AdkApp."""
+
+    def test_use_client_cert_effective_with_should_use_client_cert(self):
+        """Verifies that it respects the google-auth mTLS enablement check."""
+        with mock.patch.object(
+            mtls,
+            "should_use_client_cert",
+            return_value=True,
+            create=True,
+        ):
+            assert adk_template._use_client_cert_effective() is True
+
+    @mock.patch.dict(os.environ, {"GOOGLE_API_USE_CLIENT_CERTIFICATE": "true"})
+    def test_use_client_cert_effective_with_env_var_true(self):
+        """Verifies that it falls back to the environment variable if google-auth check fails."""
+        with mock.patch.object(
+            mtls,
+            "should_use_client_cert",
+            side_effect=AttributeError,
+            create=True,
+        ):
+            assert adk_template._use_client_cert_effective() is True
+
+    @mock.patch.dict(os.environ, {"GOOGLE_API_USE_CLIENT_CERTIFICATE": "false"})
+    def test_use_client_cert_effective_with_env_var_false(self):
+        """Verifies that it respects the environment variable being set to false."""
+        with mock.patch.object(
+            mtls,
+            "should_use_client_cert",
+            side_effect=AttributeError,
+            create=True,
+        ):
+            assert adk_template._use_client_cert_effective() is False
+
+    def test_get_api_endpoint_default(self):
+        """Verifies the default telemetry endpoint is returned when no mTLS is configured."""
+        assert (
+            adk_template._get_api_endpoint() == adk_template._DEFAULT_TELEMETRY_ENDPOINT
+        )
+
+    @mock.patch.dict(os.environ, {"GOOGLE_API_USE_MTLS_ENDPOINT": "always"})
+    def test_get_api_endpoint_always_with_cert(self):
+        """Verifies the mTLS endpoint is used when forced and a certificate is available."""
+        assert (
+            adk_template._get_api_endpoint(client_cert_source=b"cert")
+            == adk_template._DEFAULT_MTLS_TELEMETRY_ENDPOINT
+        )
+
+    @mock.patch.dict(os.environ, {"GOOGLE_API_USE_MTLS_ENDPOINT": "auto"})
+    def test_get_api_endpoint_auto_no_cert(self):
+        """Verifies it falls back to regular endpoint even if forced if no certificate is provided."""
+        assert (
+            adk_template._get_api_endpoint() == adk_template._DEFAULT_TELEMETRY_ENDPOINT
+        )
+
+    @mock.patch.dict(os.environ, {"GOOGLE_API_USE_MTLS_ENDPOINT": "never"})
+    def test_get_api_endpoint_never(self):
+        """Verifies the regular endpoint is used when mTLS is explicitly disabled."""
+        assert (
+            adk_template._get_api_endpoint(client_cert_source=b"cert")
+            == adk_template._DEFAULT_TELEMETRY_ENDPOINT
+        )
+
+    @mock.patch("google.auth.default", return_value=(mock.Mock(), _TEST_PROJECT))
+    @mock.patch.object(adk_template.requests_auth, "AuthorizedSession")
+    @mock.patch(
+        "opentelemetry.exporter.otlp.proto.http.trace_exporter.OTLPSpanExporter"
+    )
+    def test_default_instrumentor_builder_with_mtls(
+        self,
+        mock_exporter,
+        mock_session_cls,
+        mock_auth_default,
+    ):
+        """Integration test for the instrumentor builder with mTLS enabled."""
+        # Mocking to enable mTLS
+        with mock.patch.object(
+            adk_template, "_use_client_cert_effective", return_value=True
+        ):
+            with mock.patch.object(
+                mtls, "has_default_client_cert_source", return_value=True
+            ):
+                with mock.patch.object(
+                    mtls,
+                    "default_client_cert_source",
+                    return_value=lambda: b"cert",
+                ):
+                    adk_template._default_instrumentor_builder(
+                        _TEST_PROJECT_ID, enable_tracing=True
+                    )
+
+        # Verify the session was configured for mTLS
+        mock_session_cls.return_value.configure_mtls_channel.assert_called_once()
+        # Verify the exporter was initialized with the mTLS endpoint
+        mock_exporter.assert_called_once()
+        assert (
+            mock_exporter.call_args.kwargs["endpoint"]
+            == adk_template._DEFAULT_MTLS_TELEMETRY_ENDPOINT
+        )
+
+    @mock.patch("google.auth.default", return_value=(mock.Mock(), _TEST_PROJECT))
+    @mock.patch.object(adk_template.requests_auth, "AuthorizedSession")
+    def test_warn_if_telemetry_api_disabled_with_mtls(
+        self,
+        mock_session_cls,
+        mock_auth_default,
+    ):
+        """Integration test for the telemetry API check with mTLS enabled."""
+        mock_session = mock_session_cls.return_value
+        mock_session.post.return_value = mock.Mock(text="")
+
+        # Mocking to enable mTLS
+        with mock.patch.object(
+            adk_template, "_use_client_cert_effective", return_value=True
+        ):
+            with mock.patch.object(
+                mtls, "has_default_client_cert_source", return_value=True
+            ):
+                with mock.patch.object(
+                    mtls,
+                    "default_client_cert_source",
+                    return_value=lambda: b"cert",
+                ):
+                    adk_template._warn_if_telemetry_api_disabled()
+
+        # Verify mTLS channel was configured for the check request
+        mock_session.configure_mtls_channel.assert_called_once()
+        # Verify the check was performed against the mTLS endpoint
+        mock_session.post.assert_called_once_with(
+            adk_template._DEFAULT_MTLS_TELEMETRY_ENDPOINT, data=None
+        )
+
+    @mock.patch.dict(os.environ, {"GOOGLE_API_USE_MTLS_ENDPOINT": "invalid_value"})
+    def test_get_api_endpoint_invalid_env(self):
+        """Verifies it defaults to AUTO and warns on invalid env var."""
+        with mock.patch.object(adk_template, "_warn") as mock_warn:
+            assert (
+                adk_template._get_api_endpoint()
+                == adk_template._DEFAULT_TELEMETRY_ENDPOINT
+            )
+            mock_warn.assert_called_once()
+
+    @mock.patch.dict(os.environ, {"GOOGLE_API_USE_CLIENT_CERTIFICATE": "not_a_bool"})
+    def test_use_client_cert_effective_invalid_env(self):
+        """Verifies it warns on invalid boolean env var."""
+        with mock.patch.object(
+            mtls,
+            "should_use_client_cert",
+            side_effect=AttributeError,
+            create=True,
+        ):
+            with mock.patch.object(adk_template, "_warn") as mock_warn:
+                assert adk_template._use_client_cert_effective() is False
+                mock_warn.assert_called_once()
+
+    def test_use_client_cert_effective_with_should_use_client_cert_false(self):
+        """Verifies that it respects google-auth returning False for mTLS."""
+        with mock.patch.object(
+            mtls,
+            "should_use_client_cert",
+            return_value=False,
+            create=True,
+        ):
+            assert adk_template._use_client_cert_effective() is False
+
+    def test_get_api_endpoint_auto_with_cert(self):
+        """Verifies the mTLS endpoint is used in AUTO mode when a cert is available."""
+        # AUTO is the default, so we just pass a cert
+        assert (
+            adk_template._get_api_endpoint(client_cert_source=b"cert")
+            == adk_template._DEFAULT_MTLS_TELEMETRY_ENDPOINT
+        )
+
+    @mock.patch("google.auth.default", return_value=(mock.Mock(), _TEST_PROJECT))
+    @mock.patch.object(adk_template.requests_auth, "AuthorizedSession")
+    @mock.patch(
+        "opentelemetry.exporter.otlp.proto.http.trace_exporter.OTLPSpanExporter"
+    )
+    def test_default_instrumentor_builder_no_mtls(
+        self,
+        mock_exporter,
+        mock_session_cls,
+        mock_auth_default,
+    ):
+        """Integration test for the instrumentor builder with mTLS disabled."""
+        with mock.patch.object(
+            adk_template, "_use_client_cert_effective", return_value=False
+        ):
+            adk_template._default_instrumentor_builder(
+                _TEST_PROJECT_ID, enable_tracing=True
+            )
+
+        # Verify mTLS channel was NOT configured
+        mock_session_cls.return_value.configure_mtls_channel.assert_not_called()
+        # Verify the exporter was initialized with the regular endpoint
+        mock_exporter.assert_called_once()
+        assert (
+            mock_exporter.call_args.kwargs["endpoint"]
+            == adk_template._DEFAULT_TELEMETRY_ENDPOINT
+        )
+
+    @mock.patch("google.auth.default", return_value=(mock.Mock(), _TEST_PROJECT))
+    @mock.patch.object(adk_template.requests_auth, "AuthorizedSession")
+    def test_warn_if_telemetry_api_disabled_no_mtls(
+        self,
+        mock_session_cls,
+        mock_auth_default,
+    ):
+        """Integration test for the telemetry API check with mTLS disabled."""
+        mock_session = mock_session_cls.return_value
+        mock_session.post.return_value = mock.Mock(text="")
+
+        with mock.patch.object(
+            adk_template, "_use_client_cert_effective", return_value=False
+        ):
+            adk_template._warn_if_telemetry_api_disabled()
+
+        # Verify mTLS channel was NOT configured
+        mock_session.configure_mtls_channel.assert_not_called()
+        # Verify the check was performed against the regular endpoint
+        mock_session.post.assert_called_once_with(
+            adk_template._DEFAULT_TELEMETRY_ENDPOINT, data=None
+        )
+
+    @mock.patch("google.auth.default", return_value=(mock.Mock(), _TEST_PROJECT))
+    @mock.patch.object(adk_template.requests_auth, "AuthorizedSession")
+    @mock.patch(
+        "opentelemetry.exporter.otlp.proto.http.trace_exporter.OTLPSpanExporter"
+    )
+    def test_default_instrumentor_builder_mtls_no_cert_source(
+        self,
+        mock_exporter,
+        mock_session_cls,
+        mock_auth_default,
+    ):
+        """Tests that it falls back to regular endpoint if mTLS is on but no cert is found."""
+        with mock.patch.object(
+            adk_template, "_use_client_cert_effective", return_value=True
+        ):
+            with mock.patch.object(
+                mtls,
+                "has_default_client_cert_source",
+                return_value=False,
+            ):
+                adk_template._default_instrumentor_builder(
+                    _TEST_PROJECT_ID, enable_tracing=True
+                )
+
+        # Channel is configured, but endpoint remains default due to missing cert source
+        mock_session_cls.return_value.configure_mtls_channel.assert_called_once()
+        assert (
+            mock_exporter.call_args.kwargs["endpoint"]
+            == adk_template._DEFAULT_TELEMETRY_ENDPOINT
+        )