Feature request: service_json_path change watcher

Hello,
according to documentation https://cloud.google.com/endpoints/docs/openapi/get-started-kubernetes-engine-espv2#deploy_containers


Running more than 100 services fleet it is recommended to point **service_json_path** to GKE config map and use it as a cache.

The problem is that when a **new** ESP configuration is deployed and stored to a config map, the changes are not detected within endpoints-runtime service.

Such functionality works when --rollout_strategy=managed parameter is set - a newly deployed configuration is detected and reloaded.

What are your thoughts?

Am I missing anything? Is there an easier way to achieve similar using **service_json_path** parameter?

Best regards,
Julius

Start by tracing how the service_json_path parameter is read and compare it with the existing --rollout_strategy=managed change detection and reload behavior. Investigate how a GKE ConfigMap update could be observed, then verify that a newly deployed ESP configuration is detected and reloaded without managed rollout.

Written by the indexing model from the issue text.