Merge pull request #487 from yugui/fix/golint

Fixes Go lint errors and a style fix

pkg/health/health.go

@@ -24,16 +24,22 @@ import (
 
 type Status int
 
+// Status takes only one of values of these constants.
 const (
 	Healthy Status = iota
 	Unhealthy
 	Unknown
 )
 
+// HTTPGetInterface is an abstract interface for testability. It abstracts the interface of http.Client.Get.
 type HTTPGetInterface interface {
 	Get(url string) (*http.Response, error)
 }
 
+// Check checks if a GET request to the url succeeds.
+// If the HTTP response code is successful (i.e. 400 > code >= 200), it returns Healthy.
+// If the HTTP response code is unsuccessful, it returns Unhealthy.
+// It returns Unknown and err if the HTTP communication itself fails.
 func Check(url string, client HTTPGetInterface) (Status, error) {
 	res, err := client.Get(url)
 	if res.Body != nil {
@@ -44,8 +50,7 @@ func Check(url string, client HTTPGetInterface) (Status, error) {
 	}
 	if res.StatusCode >= http.StatusOK && res.StatusCode < http.StatusBadRequest {
 		return Healthy, nil
-	} else {
-		glog.V(1).Infof("Health check failed for %s, Response: %v", url, *res)
-		return Unhealthy, nil
 	}
+	glog.V(1).Infof("Health check failed for %s, Response: %v", url, *res)
+	return Unhealthy, nil
 }

pkg/health/health_check.go

@@ -25,12 +25,13 @@ import (
 	"github.com/golang/glog"
 )
 
+// HealthChecker defines an abstract interface for checking container health.
 type HealthChecker interface {
 	HealthCheck(container api.Container) (Status, error)
 }
 
-// MakeHealthChecker creates a new HealthChecker.
-func MakeHealthChecker() HealthChecker {
+// NewHealthChecker creates a new HealthChecker which supports multiple types of liveness probes.
+func NewHealthChecker() HealthChecker {
 	return &MuxHealthChecker{
 		checkers: map[string]HealthChecker{
 			"http": &HTTPHealthChecker{
@@ -45,6 +46,9 @@ type MuxHealthChecker struct {
 	checkers map[string]HealthChecker
 }
 
+// HealthCheck delegates the health-checking of the container to one of the bundled implementations.
+// It chooses an implementation according to container.LivenessProbe.Type.
+// If there is no matching health checker it returns Unknown, nil.
 func (m *MuxHealthChecker) HealthCheck(container api.Container) (Status, error) {
 	checker, ok := m.checkers[container.LivenessProbe.Type]
 	if !ok || checker == nil {
@@ -69,6 +73,7 @@ func (h *HTTPHealthChecker) findPort(container api.Container, portName string) i
 	return -1
 }
 
+// HealthCheck checks if the container is healthy by trying sending HTTP Get requests to the container.
 func (h *HTTPHealthChecker) HealthCheck(container api.Container) (Status, error) {
 	params := container.LivenessProbe.HTTPGet
 	if params == nil {

pkg/health/health_check_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 )
 
+// fakeHTTPClient is a fake implementation of HTTPGetInterface.
 type fakeHTTPClient struct {
 	req string
 	res http.Response

pkg/healthz/healthz.go

@@ -30,6 +30,7 @@ func handleHealthz(w http.ResponseWriter, r *http.Request) {
 	w.Write([]byte("ok"))
 }
 
+// InstallHandler registers a handler for health checking on the path "/healthz" to mux.
 func InstallHandler(mux *http.ServeMux) {
 	mux.HandleFunc("/healthz", handleHealthz)
 }

pkg/kubelet/kubelet.go

@@ -138,7 +138,7 @@ func (kl *Kubelet) RunKubelet(dockerEndpoint, configPath, manifestURL, etcdServe
 		}
 		go util.Forever(func() { s.ListenAndServe() }, 0)
 	}
-	kl.HealthChecker = health.MakeHealthChecker()
+	kl.HealthChecker = health.NewHealthChecker()
 	kl.syncLoop(updateChannel, kl)
 }