Information
Stackdriver logging agent needs to be activated in order to export logs to Cloud Logging.
Rationale:
If the stackdriver-logging service is not running, the logs will not be exported to Cloud Logging.
Solution
Run the following command to enable stackdriver-logging :
# systemctl start stackdriver-logging
Or update the instance metadata as follows:
# gcloud compute instances add-metadata <instance-name>
--zone <compute-zone>
--metadata google-logging-enabled=true