metrics_address should be optional parameter (#2087)

internal/registry/constants.go

@@ -1,7 +1,6 @@
 package registry
 
 import (
-	"errors"
 	"time"
 )
 
@@ -15,9 +14,3 @@ const (
 	// path metrics are available at
 	defaultMetricsPath = "/metrics"
 )
-
-var (
-	errNoMetricsAddr = errors.New("no metrics address provided")
-	errNoMetricsPort = errors.New("no metrics port provided")
-	errNoMetricsHost = errors.New("no metrics host provided")
-)

internal/registry/reporter.go

@@ -30,8 +30,7 @@ func (r *Reporter) OnConfigChange(cfg *config.Config) {
 
 	services, err := getReportedServices(cfg)
 	if err != nil {
-		log.Error().Err(err).Msg("service registry reporter")
+		log.Warn().Err(err).Msg("metrics announce to service registry is disabled")
-		return
 	}
 
 	sharedKey, err := base64.StdEncoding.DecodeString(cfg.Options.SharedKey)
@@ -63,10 +62,12 @@ func (r *Reporter) OnConfigChange(cfg *config.Config) {
 		return
 	}
 
+	if len(services) > 0 {
 		ctx, cancel := context.WithCancel(context.TODO())
 		go runReporter(ctx, pb.NewRegistryClient(registryConn), services)
 		r.cancel = cancel
 	}
+}
 
 func getReportedServices(cfg *config.Config) ([]*pb.Service, error) {
 	mu, err := metricsURL(*cfg.Options)
@@ -103,20 +104,20 @@ func metricsURL(o config.Options) (*url.URL, error) {
 	}
 
 	if o.MetricsAddr == "" {
-		return nil, errNoMetricsAddr
+		return nil, fmt.Errorf("no metrics address provided")
 	}
 
 	host, port, err := net.SplitHostPort(o.MetricsAddr)
 	if err != nil {
-		return nil, fmt.Errorf("invalid metrics address: %w", err)
+		return nil, fmt.Errorf("invalid metrics address %q: %w", o.MetricsAddr, err)
 	}
 
 	if port == "" {
-		return nil, errNoMetricsPort
+		return nil, fmt.Errorf("invalid metrics value %q: port is required", o.MetricsAddr)
 	}
 
 	if host == "" {
-		return nil, errNoMetricsHost
+		return nil, fmt.Errorf("invalid metrics value %q: either host or IP address is required", o.MetricsAddr)
 	}
 
 	return &u, nil