Merge pull request #55320 from andrewrynhard/flexvol

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>. kubeadm: Conditionally mount flexvolume **What this PR does / why we need it**: See https://github.com/kubernetes/kubeadm/issues/476 **Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*: Fixes https://github.com/kubernetes/kubeadm/issues/476 ```release-note kubeadm: Fix a bug on some OSes where the kubelet tried to mount a volume path that is non-existent and on a read-only filesystem ``` /cc @luxas

Merge pull request #55320 from andrewrynhard/flexvol
cdf4d8be · Kubernetes Submit Queue · GitHub · 54e60aca · 32f16d2c · cdf4d8be
Unverified Commit cdf4d8be authored Nov 15, 2017 by Kubernetes Submit Queue Committed by GitHub Nov 15, 2017
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Showing with 3 additions and 29 deletions

volumes.go cmd/kubeadm/app/phases/controlplane/volumes.go +3 -1

volumes_test.go cmd/kubeadm/app/phases/controlplane/volumes_test.go +0 -28

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--- a/cmd/kubeadm/app/phases/controlplane/volumes.go
+++ b/cmd/kubeadm/app/phases/controlplane/volumes.go
@@ -72,7 +72,9 @@ func getHostPathVolumesForTheControlPlane(cfg *kubeadmapi.MasterConfiguration) c
 	mounts.NewHostPathMount(kubeadmconstants.KubeControllerManager, kubeadmconstants.KubeConfigVolumeName, controllerManagerKubeConfigFile, controllerManagerKubeConfigFile, true, &hostPathFileOrCreate)
 	// Mount for the flexvolume directory (/usr/libexec/kubernetes/kubelet-plugins/volume/exec) directory
 	// Flexvolume dir must NOT be readonly as it is used for third-party plugins to integrate with their storage backends via unix domain socket.
-	mounts.NewHostPathMount(kubeadmconstants.KubeControllerManager, flexvolumeDirVolumeName, flexvolumeDirVolumePath, flexvolumeDirVolumePath, false, &hostPathDirectoryOrCreate)
+	if stat, err := os.Stat(flexvolumeDirVolumePath); err == nil && stat.IsDir() {
+		mounts.NewHostPathMount(kubeadmconstants.KubeControllerManager, flexvolumeDirVolumeName, flexvolumeDirVolumePath, flexvolumeDirVolumePath, false, &hostPathDirectoryOrCreate)
+	}

 	// HostPath volumes for the scheduler
 	// Read-only mount for the scheduler kubeconfig file

--- a/cmd/kubeadm/app/phases/controlplane/volumes_test.go
+++ b/cmd/kubeadm/app/phases/controlplane/volumes_test.go
@@ -306,15 +306,6 @@ func TestGetHostPathVolumesForTheControlPlane(t *testing.T) {
 			},
 		},
 	}
-	volMap[kubeadmconstants.KubeControllerManager]["flexvolume-dir"] = v1.Volume{
-		Name: "flexvolume-dir",
-		VolumeSource: v1.VolumeSource{
-			HostPath: &v1.HostPathVolumeSource{
-				Path: "/usr/libexec/kubernetes/kubelet-plugins/volume/exec",
-				Type: &hostPathDirectoryOrCreate,
-			},
-		},
-	}
 	volMap[kubeadmconstants.KubeScheduler] = map[string]v1.Volume{}
 	volMap[kubeadmconstants.KubeScheduler]["kubeconfig"] = v1.Volume{
 		Name: "kubeconfig",
@@ -353,11 +344,6 @@ func TestGetHostPathVolumesForTheControlPlane(t *testing.T) {
 		MountPath: "/etc/kubernetes/controller-manager.conf",
 		ReadOnly:  true,
 	}
-	volMountMap[kubeadmconstants.KubeControllerManager]["flexvolume-dir"] = v1.VolumeMount{
-		Name:      "flexvolume-dir",
-		MountPath: "/usr/libexec/kubernetes/kubelet-plugins/volume/exec",
-		ReadOnly:  false,
-	}
 	volMountMap[kubeadmconstants.KubeScheduler] = map[string]v1.VolumeMount{}
 	volMountMap[kubeadmconstants.KubeScheduler]["kubeconfig"] = v1.VolumeMount{
 		Name:      "kubeconfig",
@@ -431,15 +417,6 @@ func TestGetHostPathVolumesForTheControlPlane(t *testing.T) {
 			},
 		},
 	}
-	volMap2[kubeadmconstants.KubeControllerManager]["flexvolume-dir"] = v1.Volume{
-		Name: "flexvolume-dir",
-		VolumeSource: v1.VolumeSource{
-			HostPath: &v1.HostPathVolumeSource{
-				Path: "/usr/libexec/kubernetes/kubelet-plugins/volume/exec",
-				Type: &hostPathDirectoryOrCreate,
-			},
-		},
-	}
 	volMap2[kubeadmconstants.KubeScheduler] = map[string]v1.Volume{}
 	volMap2[kubeadmconstants.KubeScheduler]["kubeconfig"] = v1.Volume{
 		Name: "kubeconfig",
@@ -488,11 +465,6 @@ func TestGetHostPathVolumesForTheControlPlane(t *testing.T) {
 		MountPath: "/etc/kubernetes/controller-manager.conf",
 		ReadOnly:  true,
 	}
-	volMountMap2[kubeadmconstants.KubeControllerManager]["flexvolume-dir"] = v1.VolumeMount{
-		Name:      "flexvolume-dir",
-		MountPath: "/usr/libexec/kubernetes/kubelet-plugins/volume/exec",
-		ReadOnly:  false,
-	}
 	volMountMap2[kubeadmconstants.KubeScheduler] = map[string]v1.VolumeMount{}
 	volMountMap2[kubeadmconstants.KubeScheduler]["kubeconfig"] = v1.VolumeMount{
 		Name:      "kubeconfig",