Remove signal handler registration from pkg/kubelet

The goal of this change is to remove the registration of signal
handling from pkg/kubelet. We now pass in a stop channel.

If you register a signal handler in `main()` to aid in a controlled
and deliberate exit then the handler registered in `pkg/kubelet` often
wins and the process exits immediately. This means all other signal
handler registrations are currently racy if `DockerServer.Start()` is
directly or indirectly invoked.

This change also removes another signal handler registration from
`NewAPIServerCommand()`; a stop channel is now passed to this
function.

cmd/kube-apiserver/BUILD

@@ -23,6 +23,7 @@ go_library(
         "//pkg/client/metrics/prometheus:go_default_library",
         "//pkg/version/prometheus:go_default_library",
         "//vendor/github.com/spf13/pflag:go_default_library",
+        "//vendor/k8s.io/apiserver/pkg/server:go_default_library",
         "//vendor/k8s.io/apiserver/pkg/util/flag:go_default_library",
         "//vendor/k8s.io/apiserver/pkg/util/logs:go_default_library",
     ],

cmd/kube-apiserver/apiserver.go

@@ -27,6 +27,7 @@ import (
 
 	"github.com/spf13/pflag"
 
+	"k8s.io/apiserver/pkg/server"
 	utilflag "k8s.io/apiserver/pkg/util/flag"
 	"k8s.io/apiserver/pkg/util/logs"
 	"k8s.io/kubernetes/cmd/kube-apiserver/app"
@@ -37,7 +38,7 @@ import (
 func main() {
 	rand.Seed(time.Now().UTC().UnixNano())
 
-	command := app.NewAPIServerCommand()
+	command := app.NewAPIServerCommand(server.SetupSignalHandler())
 
 	// TODO: once we switch everything over to Cobra commands, we can go back to calling
 	// utilflag.InitFlags() (by removing its pflag.Parse() call). For now, we have to set the

cmd/kube-apiserver/app/server.go

@@ -48,7 +48,6 @@ import (
 	"k8s.io/apiserver/pkg/authentication/authenticator"
 	"k8s.io/apiserver/pkg/authorization/authorizer"
 	openapinamer "k8s.io/apiserver/pkg/endpoints/openapi"
-	"k8s.io/apiserver/pkg/server"
 	genericapiserver "k8s.io/apiserver/pkg/server"
 	"k8s.io/apiserver/pkg/server/filters"
 	serveroptions "k8s.io/apiserver/pkg/server/options"
@@ -109,7 +108,7 @@ const etcdRetryLimit = 60
 const etcdRetryInterval = 1 * time.Second
 
 // NewAPIServerCommand creates a *cobra.Command object with default parameters
-func NewAPIServerCommand() *cobra.Command {
+func NewAPIServerCommand(stopCh <-chan struct{}) *cobra.Command {
 	s := options.NewServerRunOptions()
 	cmd := &cobra.Command{
 		Use: "kube-apiserver",
@@ -132,7 +131,6 @@ cluster's shared state through which all other components interact.`,
 				return utilerrors.NewAggregate(errs)
 			}
 
-			stopCh := server.SetupSignalHandler()
 			return Run(completedOptions, stopCh)
 		},
 	}