feat(health): add health check detail to health api

internal/idlewatcher/health.go

@@ -65,6 +65,21 @@ func (w *Watcher) Status() health.Status {
 	return health.StatusNapping
 }
 
+// Detail implements health.HealthMonitor.
+func (w *Watcher) Detail() string {
+	state := w.state.Load()
+	if state.err != nil {
+		return state.err.Error()
+	}
+	if !state.ready {
+		return "not ready"
+	}
+	if state.status == idlewatcher.ContainerStatusRunning {
+		return "starting"
+	}
+	return "napping"
+}
+
 func checkUpdateState(key string) (w *Watcher, ready bool, err error) {
 	watcherMapMu.RLock()
 	w, ok := watcherMap[key]

internal/net/gphttp/loadbalancer/loadbalancer.go

@@ -266,6 +266,12 @@ func (lb *LoadBalancer) Status() health.Status {
 	return status
 }
 
+// Detail implements health.HealthMonitor.
+func (lb *LoadBalancer) Detail() string {
+	_, numHealthy := lb.status()
+	return fmt.Sprintf("%d/%d servers are healthy", numHealthy, lb.pool.Size())
+}
+
 func (lb *LoadBalancer) status() (status health.Status, numHealthy int) {
 	if lb.pool.Size() == 0 {
 		return health.StatusUnknown, 0

internal/route/routes/query.go

@@ -16,12 +16,14 @@ func getHealthInfo(r Route) map[string]string {
 			"status":  "unknown",
 			"uptime":  "n/a",
 			"latency": "n/a",
+			"detail":  "n/a",
 		}
 	}
 	return map[string]string{
 		"status":  mon.Status().String(),
 		"uptime":  mon.Uptime().Round(time.Second).String(),
 		"latency": mon.Latency().Round(time.Microsecond).String(),
+		"detail":  mon.Detail(),
 	}
 }
 

internal/watcher/health/monitor/monitor.go

@@ -168,6 +168,15 @@ func (mon *monitor) Latency() time.Duration {
 	return res.Latency
 }
 
+// Detail implements HealthMonitor.
+func (mon *monitor) Detail() string {
+	res := mon.lastResult.Load()
+	if res == nil {
+		return ""
+	}
+	return res.Detail
+}
+
 // Name implements HealthMonitor.
 func (mon *monitor) Name() string {
 	parts := strutils.SplitRune(mon.service, '/')

internal/watcher/health/types.go

@@ -19,6 +19,7 @@ type (
 		Status() Status
 		Uptime() time.Duration
 		Latency() time.Duration
+		Detail() string
 	}
 	HealthMonitor interface {
 		task.TaskStarter