make self-hosted kubelet optional with render flag

Author: Patrick Baxter

cmd/bootkube/render.go

@@ -33,6 +33,7 @@ var (
 		etcdServers       string
 		apiServers        string
 		altNames          string
+		selfHostKubelet   bool
 	}
 )
 
@@ -44,6 +45,7 @@ func init() {
 	cmdRender.Flags().StringVar(&renderOpts.etcdServers, "etcd-servers", "http://127.0.0.1:2379", "List of etcd servers URLs including host:port, comma separated")
 	cmdRender.Flags().StringVar(&renderOpts.apiServers, "api-servers", "https://127.0.0.1:443", "List of API server URLs including host:port, commma seprated")
 	cmdRender.Flags().StringVar(&renderOpts.altNames, "api-server-alt-names", "", "List of SANs to use in api-server certificate. Example: 'IP=127.0.0.1,IP=127.0.0.2,DNS=localhost'. If empty, SANs will be extracted from the --api-servers flag.")
+	cmdRender.Flags().BoolVar(&renderOpts.selfHostKubelet, "self-host-kubelet", true, "Set false to skip creation of and pivot to self-hosted kubelet.")
 }
 
 func runCmdRender(cmd *cobra.Command, args []string) error {
@@ -106,11 +108,12 @@ func flagsToAssetConfig() (c *asset.Config, err error) {
 		}
 	}
 	return &asset.Config{
-		EtcdServers: etcdServers,
-		CACert:      caCert,
-		CAPrivKey:   caPrivKey,
-		APIServers:  apiServers,
-		AltNames:    altNames,
+		EtcdServers:     etcdServers,
+		CACert:          caCert,
+		CAPrivKey:       caPrivKey,
+		APIServers:      apiServers,
+		AltNames:        altNames,
+		SelfHostKubelet: renderOpts.selfHostKubelet,
 	}, nil
 }
 

pkg/asset/asset.go

@@ -38,18 +38,19 @@ const (
 // AssetConfig holds all configuration needed when generating
 // the default set of assets.
 type Config struct {
-	EtcdServers []*url.URL
-	APIServers  []*url.URL
-	CACert      *x509.Certificate
-	CAPrivKey   *rsa.PrivateKey
-	AltNames    *tlsutil.AltNames
+	EtcdServers     []*url.URL
+	APIServers      []*url.URL
+	CACert          *x509.Certificate
+	CAPrivKey       *rsa.PrivateKey
+	AltNames        *tlsutil.AltNames
+	SelfHostKubelet bool
 }
 
 // NewDefaultAssets returns a list of default assets, optionally
 // configured via a user provided AssetConfig. Default assets include
 // TLS assets (certs, keys and secrets), and k8s component manifests.
 func NewDefaultAssets(conf Config) (Assets, error) {
-	as := newStaticAssets()
+	as := newStaticAssets(conf.SelfHostKubelet)
 	as = append(as, newDynamicAssets(conf)...)
 
 	// TLS assets

pkg/asset/k8s.go

@@ -17,16 +17,20 @@ const (
 	secretCMName        = "kube-controller-manager"
 )
 
-func newStaticAssets() Assets {
+func newStaticAssets(selfHostKubelet bool) Assets {
 	var noData interface{}
-	return Assets{
+	assets := Assets{
 		mustCreateAssetFromTemplate(AssetPathControllerManager, internal.ControllerManagerTemplate, noData),
 		mustCreateAssetFromTemplate(AssetPathScheduler, internal.SchedulerTemplate, noData),
-		mustCreateAssetFromTemplate(AssetPathKubelet, internal.KubeletTemplate, noData),
 		mustCreateAssetFromTemplate(AssetPathProxy, internal.ProxyTemplate, noData),
 		mustCreateAssetFromTemplate(AssetPathKubeDNSDeployment, internal.DNSDeploymentTemplate, noData),
 		mustCreateAssetFromTemplate(AssetPathKubeDNSSvc, internal.DNSSvcTemplate, noData),
 	}
+	if selfHostKubelet {
+		assets = append(assets, mustCreateAssetFromTemplate(AssetPathKubelet, internal.KubeletTemplate, noData))
+	}
+
+	return assets
 }
 
 func newDynamicAssets(conf Config) Assets {

pkg/bootkube/bootkube.go

@@ -24,7 +24,6 @@ const (
 
 var requiredPods = []string{
 	"kube-api-checkpoint",
-	"kubelet",
 	"kube-apiserver",
 	"kube-scheduler",
 	"kube-controller-manager",