Package log supports structured and unstructured logging with levels.
Debug logs arg, which can be a string or a struct, at the Debug level.
Debugf logs a formatted string at the Debug level.
Error logs arg, which can be a string or a struct, at the Error level.
Errorf logs a formatted string at the Error level.
Fatal is equivalent to Error followed by exiting the program.
Fatalf is equivalent to Errorf followed by exiting the program.
Info logs arg, which can be a string or a struct, at the Info level.
Infof logs a formatted string at the Info level.
NewContextWithLabel creates anew context from ctx that adds a label that will appear in the log entry.
NewContextWithTraceID creates a new context from ctx that adds the trace ID.
UseStackdriver switches from the default stdlib logger to a Stackdriver logger. It assumes config.Init has been called. UseStackdriver returns a "parent" *logging.Logger that should be used to log the start and end of a request. It also creates and remembers internally a "child" logger that will be used to log within a request. The two loggers are necessary to get request-scoped logs in Stackdriver. See https://cloud.google.com/appengine/docs/standard/go/writing-application-logs.
UseStackdriver can only be called once. If it is called a second time, it returns an error.