GKE application (container) logs being delivered to Cloud Logging with ERROR severity - where does that come from?

We have GKE containers emitting log messages via stdout to the console and they are being forwarded to the standard GCP logging platform. However, somehow the messages get an ERROR severity attached. The messages have a JSON payload, which has INFO level in it. I am wondering where this severity is coming from, and how I can change it. Here is an example:

Solution 1:

I came to this question with a faulty assumption. The application that is doing the logging in the container is a GoLang app, which uses the default Go logger "log". By default, that logger logs to stderr. So, because the messages are coming from stderr, they are getting marked with a ERROR severity. One can change the default output destination for the logger to be stdout, and then the log messages come with an INFO severity. However, changing back and forth, for say messages which are really errors, is messy. More work. At least I know why GKE was setting ERROR severity.