Re-add /healthz/ping handler in genericapiserver

pkg/genericapiserver/config.go

@@ -59,6 +59,7 @@ import (
 	"k8s.io/kubernetes/pkg/genericapiserver/options"
 	"k8s.io/kubernetes/pkg/genericapiserver/routes"
 	genericvalidation "k8s.io/kubernetes/pkg/genericapiserver/validation"
+	"k8s.io/kubernetes/pkg/healthz"
 	"k8s.io/kubernetes/pkg/runtime"
 	certutil "k8s.io/kubernetes/pkg/util/cert"
 	"k8s.io/kubernetes/pkg/util/sets"
@@ -124,6 +125,8 @@ type Config struct {
 	// DiscoveryAddresses is used to build the IPs pass to discovery.  If nil, the ExternalAddress is
 	// always reported
 	DiscoveryAddresses DiscoveryAddresses
+	// The default set of healthz checks. There might be more added via AddHealthzChecks dynamically.
+	HealthzChecks []healthz.HealthzChecker
 	// LegacyAPIGroupPrefixes is used to set up URL parsing for authorization and for validating requests
 	// to InstallLegacyAPIGroup.  New API servers don't generally have legacy groups at all.
 	LegacyAPIGroupPrefixes sets.String
@@ -198,6 +201,7 @@ func NewConfig() *Config {
 		RequestContextMapper:   api.NewRequestContextMapper(),
 		BuildHandlerChainsFunc: DefaultBuildHandlerChain,
 		LegacyAPIGroupPrefixes: sets.NewString(DefaultLegacyAPIPrefix),
+		HealthzChecks:          []healthz.HealthzChecker{healthz.PingHealthz},
 
 		EnableIndex:          true,
 		EnableSwaggerSupport: true,
@@ -523,6 +527,7 @@ func (c completedConfig) New() (*GenericAPIServer, error) {
 		openAPIConfig:        c.OpenAPIConfig,
 
 		postStartHooks: map[string]postStartHookEntry{},
+		healthzChecks:  c.HealthzChecks,
 	}
 
 	s.HandlerContainer = mux.NewAPIContainer(http.NewServeMux(), c.Serializer)

pkg/genericapiserver/genericapiserver_test.go

@@ -287,6 +287,14 @@ func TestPrepareRun(t *testing.T) {
 	resp, err = http.Get(server.URL + "/swaggerapi/")
 	assert.NoError(err)
 	assert.Equal(http.StatusOK, resp.StatusCode)
+
+	// healthz checks are installed in PrepareRun
+	resp, err = http.Get(server.URL + "/healthz")
+	assert.NoError(err)
+	assert.Equal(http.StatusOK, resp.StatusCode)
+	resp, err = http.Get(server.URL + "/healthz/ping")
+	assert.NoError(err)
+	assert.Equal(http.StatusOK, resp.StatusCode)
 }
 
 // TestCustomHandlerChain verifies the handler chain with custom handler chain builder functions.