fix: raise warning on import of google.monitoring.dashboard (#128)

* fix: raise warning on import of google.monitoring.dashboard

* 🦉 Updates from OwlBot

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* remove hardcoded date

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

packages/google-cloud-monitoring-dashboards/google/monitoring/dashboard/__init__.py

@@ -15,6 +15,8 @@
 # limitations under the License.
 #
 
+import warnings
+
 from google.monitoring.dashboard_v1.services.dashboards_service.async_client import (
     DashboardsServiceAsyncClient,
 )
@@ -82,3 +84,15 @@
     "Widget",
     "XyChart",
 )
+
+import_warning_message = (
+    "The client in the `google.monitoring.dashboard` namespace is no longer updated. "
+    "Please use the client in namespace `google.cloud.monitoring_dashboard` instead. "
+    "In a future release, importing code from the `google.monitoring.dashboard` namespace "
+    "may result in a RuntimeError. If you need to continue to use `google.monitoring.dashboard` "
+    "after this date, please pin to a specific version of 'google-cloud-monitoring-dashboards'. "
+    "If you have questions, please file an issue: "
+    "https://github.com/googleapis/python-monitoring-dashboards/issues."
+)
+
+warnings.warn(import_warning_message, ImportWarning)

packages/google-cloud-monitoring-dashboards/google/monitoring/dashboard_v1/__init__.py

@@ -15,6 +15,8 @@
 # limitations under the License.
 #
 
+import warnings
+
 from .services.dashboards_service import DashboardsServiceClient
 from .types.common import Aggregation
 from .types.common import PickTimeSeriesFilter
@@ -67,3 +69,15 @@
     "XyChart",
     "DashboardsServiceClient",
 )
+
+import_warning_message = (
+    "The client in the `google.monitoring.dashboard` namespace is no longer updated. "
+    "Please use the client in namespace `google.cloud.monitoring_dashboard` instead. "
+    "In a future release, importing code from the `google.monitoring.dashboard` namespace "
+    "may result in a RuntimeError. If you need to continue to use `google.monitoring.dashboard` "
+    "after this date, please pin to a specific version of 'google-cloud-monitoring-dashboards'. "
+    "If you have questions, please file an issue: "
+    "https://github.com/googleapis/python-monitoring-dashboards/issues."
+)
+
+warnings.warn(import_warning_message, ImportWarning)