Stackdriver - All logs are mapped as INFO
The Stackdriver logging agent configuration for Kubernetes defaults to INFO for any logs written to the container's stdout and ERROR for logs written to stderr. If you want finer-grained control over severity, you can configure Spring to log as single-line JSON (e.g., via JsonLayout1) and let the logging agent pick up the severity from the JSON object (see https://cloud.google.com/logging/docs/agent/configuration#process-payload).
1By default, JsonLayout will use "level" for the log level, while the Stackdriver logging agent recognizes "severity", so you may have to override addCustomDataToJsonMap.