func ExampleNewLogger_levelColors() {
// Color by level value
colorFn := func(keyvals ...interface{}) term.FgBgColor {
for i := 0; i < len(keyvals)-1; i += 2 {
if keyvals[i] != "level" {
continue
}
switch keyvals[i+1] {
case "debug":
return term.FgBgColor{Fg: term.DarkGray}
case "info":
return term.FgBgColor{Fg: term.Gray}
case "warn":
return term.FgBgColor{Fg: term.Yellow}
case "error":
return term.FgBgColor{Fg: term.Red}
case "crit":
return term.FgBgColor{Fg: term.Gray, Bg: term.DarkRed}
default:
return term.FgBgColor{}
}
}
return term.FgBgColor{}
}
logger := term.NewLogger(os.Stdout, log.NewJSONLogger, colorFn)
logger.Log("level", "warn", "msg", "yellow")
logger.Log("level", "debug", "msg", "dark gray")
}
func ExampleNewLogger_redErrors() {
// Color errors red
colorFn := func(keyvals ...interface{}) term.FgBgColor {
for i := 1; i < len(keyvals); i += 2 {
if _, ok := keyvals[i].(error); ok {
return term.FgBgColor{Fg: term.White, Bg: term.Red}
}
}
return term.FgBgColor{}
}
logger := term.NewLogger(os.Stdout, log.NewLogfmtLogger, colorFn)
logger.Log("msg", "default color", "err", nil)
logger.Log("msg", "colored because of error", "err", errors.New("coloring error"))
}
func init() {
termLog = log.NewLogfmtLogger(os.Stderr)
if term.IsTerminal(os.Stderr) {
termLog = term.NewLogger(
os.Stderr,
log.NewLogfmtLogger,
kithlp.NewLevelColorer("level", nil),
)
}
logBase.Swap(termLog)
lg := kithlp.StringifyLogger{logBase}
Logger = log.NewContext(lg).With("ts", log.DefaultTimestampUTC, "caller", log.Caller(4))
logger = levels.New(Logger)
stdlog.SetOutput(log.NewStdlibAdapter(logBase))
converter.Logger.Swap(Logger)
}