Move from bool to HealthCheckStatus

pkg/kubelet/health_check.go

@@ -25,10 +25,16 @@ import (
 	"github.com/golang/glog"
 )
 
-// HealthChecker is an abstract interface for container health checker.
+type HealthCheckStatus int
+
+const (
+	CheckHealthy   HealthCheckStatus = 0
+	CheckUnhealthy HealthCheckStatus = 1
+	CheckUnknown   HealthCheckStatus = 2
+)
+
 type HealthChecker interface {
-	// IsHealthy checks if the container is healthy.
-	IsHealthy(container api.Container) (bool, error)
+	HealthCheck(container api.Container) (HealthCheckStatus, error)
 }
 
 type httpDoInterface interface {
@@ -51,14 +57,13 @@ type MuxHealthChecker struct {
 	checkers map[string]HealthChecker
 }
 
-// IsHealthy checks the health of the container by delegating to an appropriate HealthChecker according to container.LivenessProbe.Type.
-func (m *MuxHealthChecker) IsHealthy(container api.Container) (bool, error) {
+func (m *MuxHealthChecker) HealthCheck(container api.Container) (HealthCheckStatus, error) {
 	checker, ok := m.checkers[container.LivenessProbe.Type]
 	if !ok || checker == nil {
 		glog.Warningf("Failed to find health checker for %s %s", container.Name, container.LivenessProbe.Type)
-		return true, nil
+		return CheckUnknown, nil
 	}
-	return checker.IsHealthy(container)
+	return checker.HealthCheck(container)
 }
 
 // HTTPHealthChecker is an implementation of HealthChecker which checks container health by sending HTTP Get requests.
@@ -76,18 +81,17 @@ func (h *HTTPHealthChecker) findPort(container api.Container, portName string) i
 	return -1
 }
 
-// IsHealthy checks if the container is healthy by trying sending HTTP Get requests to the container.
-func (h *HTTPHealthChecker) IsHealthy(container api.Container) (bool, error) {
+func (h *HTTPHealthChecker) HealthCheck(container api.Container) (HealthCheckStatus, error) {
 	params := container.LivenessProbe.HTTPGet
 	if params == nil {
-		return true, fmt.Errorf("Error, no HTTP parameters specified: %v", container)
+		return CheckUnknown, fmt.Errorf("Error, no HTTP parameters specified: %v", container)
 	}
 	port := h.findPort(container, params.Port)
 	if port == -1 {
 		var err error
 		port, err = strconv.ParseInt(params.Port, 10, 0)
 		if err != nil {
-			return true, err
+			return CheckUnknown, err
 		}
 	}
 	var host string
@@ -103,7 +107,11 @@ func (h *HTTPHealthChecker) IsHealthy(container api.Container) (bool, error) {
 	}
 	if err != nil {
 		// At this point, if it fails, its either a policy (unlikely) or HTTP protocol (likely) error.
-		return false, nil
+		return CheckUnhealthy, nil
 	}
-	return res.StatusCode == http.StatusOK, nil
+	if res.StatusCode == http.StatusOK {
+		return CheckHealthy, nil
+	}
+	glog.V(1).Infof("Health check failed for %v, Response: %v", container, *res)
+	return CheckUnhealthy, nil
 }

pkg/kubelet/health_check_test.go

@@ -55,8 +55,8 @@ func TestHttpHealth(t *testing.T) {
 		},
 	}
 
-	ok, err := check.IsHealthy(container)
-	if !ok {
+	ok, err := check.HealthCheck(container)
+	if ok != CheckHealthy {
 		t.Error("Unexpected unhealthy")
 	}
 	if err != nil {

pkg/kubelet/kubelet.go

@@ -732,7 +732,7 @@ func (kl *Kubelet) syncManifest(manifest *api.ContainerManifest, keepChannel cha
 				glog.V(1).Infof("health check errored: %v", err)
 				continue
 			}
-			if !healthy {
+			if healthy != CheckHealthy {
 				glog.V(1).Infof("manifest %s container %s is unhealthy.", manifest.ID, container.Name)
 				if err != nil {
 					glog.V(1).Infof("Failed to get container info %v, for %s", err, containerID)
@@ -989,16 +989,16 @@ func (kl *Kubelet) GetMachineStats() (*api.ContainerStats, error) {
 	return kl.statsFromContainerPath("/")
 }
 
-func (kl *Kubelet) healthy(container api.Container, dockerContainer *docker.APIContainers) (bool, error) {
+func (kl *Kubelet) healthy(container api.Container, dockerContainer *docker.APIContainers) (HealthCheckStatus, error) {
 	// Give the container 60 seconds to start up.
 	if container.LivenessProbe == nil {
-		return true, nil
+		return CheckHealthy, nil
 	}
 	if time.Now().Unix()-dockerContainer.Created < container.LivenessProbe.InitialDelaySeconds {
-		return true, nil
+		return CheckHealthy, nil
 	}
 	if kl.HealthChecker == nil {
-		return true, nil
+		return CheckHealthy, nil
 	}
-	return kl.HealthChecker.IsHealthy(container)
+	return kl.HealthChecker.HealthCheck(container)
 }

pkg/kubelet/kubelet_test.go

@@ -424,8 +424,8 @@ func TestSyncManifestsDeletes(t *testing.T) {
 
 type FalseHealthChecker struct{}
 
-func (f *FalseHealthChecker) IsHealthy(container api.Container) (bool, error) {
-	return false, nil
+func (f *FalseHealthChecker) HealthCheck(container api.Container) (HealthCheckStatus, error) {
+	return CheckUnhealthy, nil
 }
 
 func TestSyncManifestsUnhealthy(t *testing.T) {