GetLevelFrom env will look at the environment var `SM_LOG_LEVEL` and convert it into the appropriate LogLevel.

NewConsoleLogger returns a new Logger instance which will log to the console.

NewGCloudLogger returns a new Logger instance which can be used for structured google cloud logging.

NewGCloudLoggerWithSink returns a new Logger instance using a sink and suppressing the console logging.

NewJSONLogger returns a new Logger instance which can be used for structured logging.

NewJSONLoggerWithSink returns a new Logger instance using a sink and suppressing the console logging.

NewTestLogger returns a new Logger instance useful for testing.

JSONLogEntry defines a log entry this is modeled after the JSON format expected by Cloud Logging https://github.com/GoogleCloudPlatform/golang-samples/blob/08bc985b4973901c09344eabbe9d7d5add7dc656/run/logging-manual/main.go.

Logger is an interface for logging.

LogLevel defines the level of logging.