fix data race

internal/watcher/health/config.go

@@ -14,7 +14,9 @@ type HealthCheckConfig struct {
 	Timeout  time.Duration `json:"timeout" validate:"omitempty,min=1s"`
 }
 
-var DefaultHealthConfig = &HealthCheckConfig{
-	Interval: common.HealthCheckIntervalDefault,
-	Timeout:  common.HealthCheckTimeoutDefault,
+func DefaultHealthConfig() *HealthCheckConfig {
+	return &HealthCheckConfig{
+		Interval: common.HealthCheckIntervalDefault,
+		Timeout:  common.HealthCheckTimeoutDefault,
+	}
 }

internal/watcher/health/monitor/monitor.go

@@ -25,7 +25,7 @@ type (
 		url     atomic.Value[*types.URL]
 
 		status     atomic.Value[health.Status]
-		lastResult *health.HealthCheckResult
+		lastResult atomic.Value[*health.HealthCheckResult]
 
 		checkHealth HealthCheckFunc
 		startTime   time.Time
@@ -139,10 +139,11 @@ func (mon *monitor) Uptime() time.Duration {
 
 // Latency implements HealthMonitor.
 func (mon *monitor) Latency() time.Duration {
-	if mon.lastResult == nil {
+	res := mon.lastResult.Load()
+	if res == nil {
 		return 0
 	}
-	return mon.lastResult.Latency
+	return res.Latency
 }
 
 // Name implements HealthMonitor.
@@ -158,7 +159,7 @@ func (mon *monitor) String() string {
 
 // MarshalJSON implements json.Marshaler of HealthMonitor.
 func (mon *monitor) MarshalJSON() ([]byte, error) {
-	res := mon.lastResult
+	res := mon.lastResult.Load()
 	if res == nil {
 		res = &health.HealthCheckResult{
 			Healthy: true,
@@ -190,7 +191,7 @@ func (mon *monitor) checkUpdateHealth() error {
 		return nil
 	}
 
-	mon.lastResult = result
+	mon.lastResult.Store(result)
 	var status health.Status
 	if result.Healthy {
 		status = health.StatusHealthy