func init() { startTime := time.Now().UTC() expvar.Publish("Uptime", expvar.Func(func() interface{} { return int64(time.Since(startTime)) })) expvar.Publish("Goroutines", expvar.Func(func() interface{} { return runtime.NumGoroutine() })) // subscribe to the broker in order to report data about current graph c := broker.Get().Subscribe() // Instantiate a real, empty graph to ensure the interface type is never nil when it might be called var g system.CoreGraph = represent.NewGraph() go func() { for latest := range c { g = latest } }() expvar.Publish("MsgId", expvar.Func(func() interface{} { return g.MsgId() })) go func() { log.Println(http.ListenAndServe("localhost:6060", nil)) }() }