Updating server dependancies. (#7816)

vendor/github.com/prometheus/common/log/log.go

@@ -56,11 +56,11 @@ func (s *loggerSettings) apply(ctx *kingpin.ParseContext) error {
 // To use the default Kingpin application, call AddFlags(kingpin.CommandLine)
 func AddFlags(a *kingpin.Application) {
 	s := loggerSettings{}
-	kingpin.Flag("log.level", "Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal]").
+	a.Flag("log.level", "Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal]").
 		Default(origLogger.Level.String()).
 		StringVar(&s.level)
 	defaultFormat := url.URL{Scheme: "logger", Opaque: "stderr"}
-	kingpin.Flag("log.format", `Set the log target and format. Example: "logger:syslog?appname=bob&local=7" or "logger:stdout?json=true"`).
+	a.Flag("log.format", `Set the log target and format. Example: "logger:syslog?appname=bob&local=7" or "logger:stdout?json=true"`).
 		Default(defaultFormat.String()).
 		StringVar(&s.format)
 	a.Action(s.apply)
@@ -345,6 +345,11 @@ func Fatalf(format string, args ...interface{}) {
 	baseLogger.sourced().Fatalf(format, args...)
 }
 
+// AddHook adds hook to Prometheus' original logger.
+func AddHook(hook logrus.Hook) {
+	origLogger.Hooks.Add(hook)
+}
+
 type errorLogWriter struct{}
 
 func (errorLogWriter) Write(b []byte) (int, error) {