metrics: fix healthcheck

metrics/healthcheck.go

@@ -1,61 +1,35 @@
 package metrics
 
-// Healthcheck holds an error value describing an arbitrary up/down status.
-type Healthcheck interface {
-	Check()
-	Error() error
-	Healthy()
-	Unhealthy(error)
-}
-
 // NewHealthcheck constructs a new Healthcheck which will use the given
 // function to update its status.
-func NewHealthcheck(f func(Healthcheck)) Healthcheck {
-	if !Enabled {
-		return NilHealthcheck{}
-	}
-	return &StandardHealthcheck{nil, f}
+func NewHealthcheck(f func(*Healthcheck)) *Healthcheck {
+	return &Healthcheck{nil, f}
 }
 
-// NilHealthcheck is a no-op.
-type NilHealthcheck struct{}
-
-// Check is a no-op.
-func (NilHealthcheck) Check() {}
-
-// Error is a no-op.
-func (NilHealthcheck) Error() error { return nil }
-
-// Healthy is a no-op.
-func (NilHealthcheck) Healthy() {}
-
-// Unhealthy is a no-op.
-func (NilHealthcheck) Unhealthy(error) {}
-
-// StandardHealthcheck is the standard implementation of a Healthcheck and
+// Healthcheck is the standard implementation of a Healthcheck and
 // stores the status and a function to call to update the status.
-type StandardHealthcheck struct {
+type Healthcheck struct {
 	err error
-	f   func(Healthcheck)
+	f   func(*Healthcheck)
 }
 
 // Check runs the healthcheck function to update the healthcheck's status.
-func (h *StandardHealthcheck) Check() {
+func (h *Healthcheck) Check() {
 	h.f(h)
 }
 
 // Error returns the healthcheck's status, which will be nil if it is healthy.
-func (h *StandardHealthcheck) Error() error {
+func (h *Healthcheck) Error() error {
 	return h.err
 }
 
 // Healthy marks the healthcheck as healthy.
-func (h *StandardHealthcheck) Healthy() {
+func (h *Healthcheck) Healthy() {
 	h.err = nil
 }
 
 // Unhealthy marks the healthcheck as unhealthy.  The error is stored and
 // may be retrieved by the Error method.
-func (h *StandardHealthcheck) Unhealthy(err error) {
+func (h *Healthcheck) Unhealthy(err error) {
 	h.err = err
 }

metrics/log.go

@@ -36,10 +36,6 @@ func LogScaled(r Registry, freq time.Duration, scale time.Duration, l Logger) {
 			case *GaugeInfo:
 				l.Printf("gauge %s\n", name)
 				l.Printf("  value:       %s\n", metric.Snapshot().Value())
-			case Healthcheck:
-				metric.Check()
-				l.Printf("healthcheck %s\n", name)
-				l.Printf("  error:       %v\n", metric.Error())
 			case Histogram:
 				h := metric.Snapshot()
 				ps := h.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999})

metrics/registry.go

@@ -136,7 +136,7 @@ func (r *StandardRegistry) Register(name string, i interface{}) error {
 // RunHealthchecks run all registered healthchecks.
 func (r *StandardRegistry) RunHealthchecks() {
 	r.metrics.Range(func(key, value any) bool {
-		if h, ok := value.(Healthcheck); ok {
+		if h, ok := value.(*Healthcheck); ok {
 			h.Check()
 		}
 		return true
@@ -157,7 +157,7 @@ func (r *StandardRegistry) GetAll() map[string]map[string]interface{} {
 			values["value"] = metric.Snapshot().Value()
 		case *GaugeFloat64:
 			values["value"] = metric.Snapshot().Value()
-		case Healthcheck:
+		case *Healthcheck:
 			values["error"] = nil
 			metric.Check()
 			if err := metric.Error(); nil != err {
@@ -214,7 +214,7 @@ func (r *StandardRegistry) Unregister(name string) {
 
 func (r *StandardRegistry) loadOrRegister(name string, i interface{}) (interface{}, bool, bool) {
 	switch i.(type) {
-	case *Counter, *CounterFloat64, *Gauge, *GaugeFloat64, *GaugeInfo, Healthcheck, Histogram, Meter, Timer, ResettingTimer:
+	case *Counter, *CounterFloat64, *Gauge, *GaugeFloat64, *GaugeInfo, *Healthcheck, Histogram, Meter, Timer, ResettingTimer:
 	default:
 		return nil, false, false
 	}

metrics/syslog.go

@@ -25,7 +25,7 @@ func Syslog(r Registry, d time.Duration, w *syslog.Writer) {
 				w.Info(fmt.Sprintf("gauge %s: value: %f", name, metric.Snapshot().Value()))
 			case *GaugeInfo:
 				w.Info(fmt.Sprintf("gauge %s: value: %s", name, metric.Snapshot().Value()))
-			case Healthcheck:
+			case *Healthcheck:
 				metric.Check()
 				w.Info(fmt.Sprintf("healthcheck %s: error: %v", name, metric.Error()))
 			case Histogram:

metrics/writer.go

@@ -41,7 +41,7 @@ func WriteOnce(r Registry, w io.Writer) {
 		case *GaugeInfo:
 			fmt.Fprintf(w, "gauge %s\n", namedMetric.name)
 			fmt.Fprintf(w, "  value:       %s\n", metric.Snapshot().Value().String())
-		case Healthcheck:
+		case *Healthcheck:
 			metric.Check()
 			fmt.Fprintf(w, "healthcheck %s\n", namedMetric.name)
 			fmt.Fprintf(w, "  error:       %v\n", metric.Error())