Fix kubernetes-csi#128 - Cannot attach raw block volumes

CSI has supported raw block volumes since version 0.1, and Kubernetes since v1.9, but the external-attacher cannot attach a block volume. When attaching a raw block volume we don't even see an error on the external-attacher logs saying it cannot handle it, it just goes ahead assuming it's a mount type of volume. This patch checks the volume mode on the spec to see if it's a raw volume or not. The the volume mode is define and it's PVBlock we'll use the Block access type, in any other case (undefined and Filesystem mode) we'll use the Mount access type.
kbsonlong · Mar 5, 2019 · a525eb9 · a525eb9
1 parent 0e6f5f2
commit a525eb9
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Showing 2 changed files with 53 additions and 11 deletions.
diff --git a/pkg/controller/util.go b/pkg/controller/util.go
@@ -146,19 +146,30 @@ func GetVolumeCapabilities(pv *v1.PersistentVolume, csiSource *v1.CSIPersistentV
 		return nil, fmt.Errorf("CSI volume source was nil")
 	}
 
-	fsType := csiSource.FSType
-	if len(fsType) == 0 {
-		fsType = defaultFSType
-	}
+	var cap *csi.VolumeCapability
+	if pv.Spec.VolumeMode != nil && *pv.Spec.VolumeMode == v1.PersistentVolumeBlock {
+		cap = &csi.VolumeCapability{
+			AccessType: &csi.VolumeCapability_Block{
+				Block: &csi.VolumeCapability_BlockVolume{},
+			},
+			AccessMode: &csi.VolumeCapability_AccessMode{},
+		}
 
-	cap := &csi.VolumeCapability{
-		AccessType: &csi.VolumeCapability_Mount{
-			Mount: &csi.VolumeCapability_MountVolume{
-				FsType:     fsType,
-				MountFlags: pv.Spec.MountOptions,
+	} else {
+		fsType := csiSource.FSType
+		if len(fsType) == 0 {
+			fsType = defaultFSType
+		}
+
+		cap = &csi.VolumeCapability{
+			AccessType: &csi.VolumeCapability_Mount{
+				Mount: &csi.VolumeCapability_MountVolume{
+					FsType:     fsType,
+					MountFlags: pv.Spec.MountOptions,
+				},
 			},
-		},
-		AccessMode: &csi.VolumeCapability_AccessMode{},
+			AccessMode: &csi.VolumeCapability_AccessMode{},
+		}
 	}
 
 	// Translate array of modes into single VolumeCapability

diff --git a/pkg/controller/util_test.go b/pkg/controller/util_test.go
@@ -77,6 +77,17 @@ func TestGetNodeIDFromNode(t *testing.T) {
 	}
 }
 
+func createBlockCapability(mode csi.VolumeCapability_AccessMode_Mode) *csi.VolumeCapability {
+	return &csi.VolumeCapability{
+		AccessType: &csi.VolumeCapability_Block{
+			Block: &csi.VolumeCapability_BlockVolume{},
+		},
+		AccessMode: &csi.VolumeCapability_AccessMode{
+			Mode: mode,
+		},
+	}
+}
+
 func createMountCapability(fsType string, mode csi.VolumeCapability_AccessMode_Mode, mountOptions []string) *csi.VolumeCapability {
 	return &csi.VolumeCapability{
 		AccessType: &csi.VolumeCapability_Mount{
@@ -92,8 +103,12 @@ func createMountCapability(fsType string, mode csi.VolumeCapability_AccessMode_M
 }
 
 func TestGetVolumeCapabilities(t *testing.T) {
+	blockVolumeMode := v1.PersistentVolumeMode(v1.PersistentVolumeBlock)
+	filesystemVolumeMode := v1.PersistentVolumeMode(v1.PersistentVolumeFilesystem)
+
 	tests := []struct {
 		name               string
+		volumeMode         *v1.PersistentVolumeMode
 		fsType             string
 		modes              []v1.PersistentVolumeAccessMode
 		mountOptions       []string
@@ -102,10 +117,18 @@ func TestGetVolumeCapabilities(t *testing.T) {
 	}{
 		{
 			name:               "RWX",
+			volumeMode:         &filesystemVolumeMode,
 			modes:              []v1.PersistentVolumeAccessMode{v1.ReadWriteMany},
 			expectedCapability: createMountCapability(defaultFSType, csi.VolumeCapability_AccessMode_MULTI_NODE_MULTI_WRITER, nil),
 			expectError:        false,
 		},
+		{
+			name:               "Block RWX",
+			volumeMode:         &blockVolumeMode,
+			modes:              []v1.PersistentVolumeAccessMode{v1.ReadWriteMany},
+			expectedCapability: createBlockCapability(csi.VolumeCapability_AccessMode_MULTI_NODE_MULTI_WRITER),
+			expectError:        false,
+		},
 		{
 			name:               "RWX + specified fsType",
 			fsType:             "ext3",
@@ -119,6 +142,13 @@ func TestGetVolumeCapabilities(t *testing.T) {
 			expectedCapability: createMountCapability(defaultFSType, csi.VolumeCapability_AccessMode_SINGLE_NODE_WRITER, nil),
 			expectError:        false,
 		},
+		{
+			name:               "Block RWO",
+			volumeMode:         &blockVolumeMode,
+			modes:              []v1.PersistentVolumeAccessMode{v1.ReadWriteOnce},
+			expectedCapability: createBlockCapability(csi.VolumeCapability_AccessMode_SINGLE_NODE_WRITER),
+			expectError:        false,
+		},
 		{
 			name:               "ROX",
 			modes:              []v1.PersistentVolumeAccessMode{v1.ReadOnlyMany},
@@ -155,6 +185,7 @@ func TestGetVolumeCapabilities(t *testing.T) {
 	for _, test := range tests {
 		pv := &v1.PersistentVolume{
 			Spec: v1.PersistentVolumeSpec{
+				VolumeMode:   test.volumeMode,
 				AccessModes:  test.modes,
 				MountOptions: test.mountOptions,
 				PersistentVolumeSource: v1.PersistentVolumeSource{