feat(otel): add --otel_to_cloud experimental support

Cloud Trace, Cloud Monitoring and Cloud Logging integrations are set up via OTel if otel_to_cloud CLI param/fast_api arg is provided.

This is similar to current Cloud Trace integration via trace_to_cloud, just extended to Monitoring and Logging as well.

PiperOrigin-RevId: 807385680

tests/unittests/telemetry/test_google_cloud.py

@@ -0,0 +1,57 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from unittest import mock
+
+from google.adk.telemetry.google_cloud import get_gcp_exporters
+import pytest
+
+
+@pytest.mark.parametrize("enable_cloud_tracing", [True, False])
+@pytest.mark.parametrize("enable_cloud_metrics", [True, False])
+@pytest.mark.parametrize("enable_cloud_logging", [True, False])
+def test_get_gcp_exporters(
+    enable_cloud_tracing: bool,
+    enable_cloud_metrics: bool,
+    enable_cloud_logging: bool,
+    monkeypatch: pytest.MonkeyPatch,
+):
+  """
+  Test initializing correct providers in setup_otel
+  when enabling telemetry via Google O11y.
+  """
+  # Arrange.
+  # Mocking google.auth.default to improve the test time.
+  auth_mock = mock.MagicMock()
+  auth_mock.return_value = ("", "project-id")
+  monkeypatch.setattr(
+      "google.auth.default",
+      auth_mock,
+  )
+
+  # Act.
+  otel_hooks = get_gcp_exporters(
+      enable_cloud_tracing=enable_cloud_tracing,
+      enable_cloud_metrics=enable_cloud_metrics,
+      enable_cloud_logging=enable_cloud_logging,
+  )
+
+  # Assert.
+  # If given telemetry type was enabled,
+  # the corresponding provider should be set.
+  assert len(otel_hooks.span_processors) == (1 if enable_cloud_tracing else 0)
+  assert len(otel_hooks.metric_readers) == (1 if enable_cloud_metrics else 0)
+  assert len(otel_hooks.log_record_processors) == (
+      1 if enable_cloud_logging else 0
+  )