log is a little wrapper on top of the original log package to provide the log level feature, eg:

log.Info("Hello world")
log.Errorf("Download failed because: %s", err)
log.Warning("Something went wrong")
log.Fatal(err)

In addition, the log.Fatal function exits after printing the stack trace of the current goroutine.

Finally, level prefixes are formatted as <LEVEL> -- <msg> - solely to match the default format of vcap_logging. Ideally it should be made configurable using the text/template package.