fix(loki/src/k8s_events): correctly update health state for the component during operation

Signed-off-by: hainenber <dotronghai96@gmail.com>

Author: hainenber

CHANGELOG.md

@@ -85,6 +85,9 @@ Main (unreleased)
 
 - Fix bug where custom headers were not actually being set in loki client. (@captncraig)
 
+- Fix bug where `loki.source.kubernetes_events` unable to register as unhealthy
+  when there are failures for underlying informers. (@hainenber)
+
 ### Other changes
 
 - Removed support for Windows 2012 in line with Microsoft end of life. (@mattdurham)

component/loki/source/kubernetes_events/kubernetes_events.go

@@ -93,11 +93,15 @@ type Component struct {
 
 	receiversMut sync.RWMutex
 	receivers    []loki.LogsReceiver
+
+	healthMut sync.RWMutex
+	health    component.Health
 }
 
 var (
-	_ component.Component      = (*Component)(nil)
-	_ component.DebugComponent = (*Component)(nil)
+	_ component.Component       = (*Component)(nil)
+	_ component.DebugComponent  = (*Component)(nil)
+	_ component.HealthComponent = (*Component)(nil)
 )
 
 // New creates a new loki.source.kubernetes_events component.
@@ -152,6 +156,7 @@ func (c *Component) Run(ctx context.Context) error {
 				c.tasksMut.RUnlock()
 
 				if err := c.runner.ApplyTasks(ctx, tasks); err != nil {
+					c.setHealth(err)
 					level.Error(c.log).Log("msg", "failed to apply event watchers", "err", err)
 				}
 			}
@@ -180,7 +185,10 @@ func (c *Component) Run(ctx context.Context) error {
 		cancel()
 	})
 
-	return rg.Run()
+	err := rg.Run()
+	c.setHealth(err)
+
+	return err
 }
 
 // Update implements component.Component.
@@ -255,3 +263,29 @@ func (c *Component) DebugInfo() interface{} {
 	}
 	return info
 }
+
+// CurrentHealth implements component.HealthComponent
+func (c *Component) CurrentHealth() component.Health {
+	c.healthMut.RLock()
+	defer c.healthMut.RUnlock()
+	return c.health
+}
+
+func (c *Component) setHealth(err error) {
+	c.healthMut.Lock()
+	defer c.healthMut.Unlock()
+
+	if err == nil {
+		c.health = component.Health{
+			Health:     component.HealthTypeHealthy,
+			Message:    "component is ready",
+			UpdateTime: time.Now(),
+		}
+	} else {
+		c.health = component.Health{
+			Health:     component.HealthTypeUnhealthy,
+			Message:    fmt.Sprintf("component encounters error: %s", err),
+			UpdateTime: time.Now(),
+		}
+	}
+}