kubeadm: do not create etcd datastore if we are in dryrun mode

cmd/kubeadm/app/cmd/join.go

@@ -571,6 +571,11 @@ func (j *joinData) PostInstallControlPlane(initConfiguration *kubeadmapi.InitCon
 
 	// in case of local etcd
 	if initConfiguration.Etcd.External == nil {
+		// creates target folder if doesn't exist already
+		if err := os.MkdirAll(initConfiguration.Etcd.Local.DataDir, 0700); err != nil {
+			return errors.Wrapf(err, "failed to create etcd directory %q", initConfiguration.Etcd.Local.DataDir)
+		}
+
 		// Adds a new etcd instance; in order to do this the new etcd instance should be "announced" to
 		// the existing etcd members before being created.
 		// This operation must be executed after kubelet is already started in order to minimize the time

cmd/kubeadm/app/cmd/phases/init/etcd.go

@@ -18,6 +18,7 @@ package phases
 
 import (
 	"fmt"
+	"os"
 
 	"github.com/pkg/errors"
 	"k8s.io/klog"
@@ -31,7 +32,7 @@ import (
 
 var (
 	etcdLocalExample = normalizer.Examples(`
-		# Generates the static Pod manifest file for etcd, functionally 
+		# Generates the static Pod manifest file for etcd, functionally
 		# equivalent to what is generated by kubeadm init.
 		kubeadm init phase etcd local
 
@@ -43,6 +44,7 @@ var (
 
 type etcdData interface {
 	Cfg() *kubeadmapi.InitConfiguration
+	DryRun() bool
 	ManifestDir() string
 }
 
@@ -89,6 +91,14 @@ func runEtcdPhaseLocal() func(c workflow.RunData) error {
 
 		// Add etcd static pod spec only if external etcd is not configured
 		if cfg.Etcd.External == nil {
+			// creates target folder if doesn't exist already
+			if !data.DryRun() {
+				if err := os.MkdirAll(cfg.Etcd.Local.DataDir, 0700); err != nil {
+					return errors.Wrapf(err, "failed to create etcd directory %q", cfg.Etcd.Local.DataDir)
+				}
+			} else {
+				fmt.Printf("[dryrun] Would ensure that %q directory is present\n", cfg.Etcd.Local.DataDir)
+			}
 			fmt.Printf("[etcd] Creating static Pod manifest for local etcd in %q\n", data.ManifestDir())
 			if err := etcdphase.CreateLocalEtcdStaticPodManifestFile(data.ManifestDir(), cfg.NodeRegistration.Name, &cfg.ClusterConfiguration, &cfg.LocalAPIEndpoint); err != nil {
 				return errors.Wrap(err, "error creating local etcd static pod manifest file")

cmd/kubeadm/app/phases/etcd/local.go

@@ -18,7 +18,6 @@ package etcd
 
 import (
 	"fmt"
-	"os"
 	"path/filepath"
 	"strings"
 	"time"
@@ -51,14 +50,8 @@ func CreateLocalEtcdStaticPodManifestFile(manifestDir string, nodeName string, c
 		return errors.New("etcd static pod manifest cannot be generated for cluster using external etcd")
 	}
 	// gets etcd StaticPodSpec
-	emptyInitialCluster := []etcdutil.Member{}
+	spec := GetEtcdPodSpec(cfg, endpoint, nodeName, []etcdutil.Member{})
 
-	// creates target folder if not already exists
-	if err := os.MkdirAll(cfg.Etcd.Local.DataDir, 0700); err != nil {
-		return errors.Wrapf(err, "failed to create etcd directory %q", cfg.Etcd.Local.DataDir)
-	}
-
-	spec := GetEtcdPodSpec(cfg, endpoint, nodeName, emptyInitialCluster)
 	// writes etcd StaticPod to disk
 	if err := staticpodutil.WriteStaticPodToDisk(kubeadmconstants.Etcd, manifestDir, spec); err != nil {
 		return err
@@ -110,11 +103,6 @@ func CreateStackedEtcdStaticPodManifestFile(client clientset.Interface, manifest
 	fmt.Println("[etcd] Announced new etcd member joining to the existing etcd cluster")
 	klog.V(1).Infof("Updated etcd member list: %v", initialCluster)
 
-	// creates target folder if not already exists
-	if err := os.MkdirAll(cfg.Etcd.Local.DataDir, 0700); err != nil {
-		return errors.Wrapf(err, "failed to create etcd directory %q", cfg.Etcd.Local.DataDir)
-	}
-
 	klog.V(1).Info("Creating local etcd static pod manifest file")
 	// gets etcd StaticPodSpec, actualized for the current InitConfiguration and the new list of etcd members
 	spec := GetEtcdPodSpec(cfg, endpoint, nodeName, initialCluster)